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CTS 3.6L 2005 80,000 Miles
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Correct - here's some shots of it in the car....





Now here's the interesting part (and a confirmation that the ABS Pressure Modulator actually fixed the issue).

I bled the thing like you wouldn't believe. In fact, it was more of a flush then anything else as I ended up putting 2 liters of brake fluid through it. Of course, the master had run dry during the modulator replacement so everything was full of air.

I pressure bled it at first to get it started and then gravity bled the daylights out of it. I then test drove it and bled the master some more until brake operation and the pedal worked perfectly. Now here's the kicker....

I was basing the pedal feel on how the pedal felt prior to repair, which was high and hard. I really liked the feel of the pedal prior to repair. However, after some driving and re-bleeding I was certain I had gotten as much air out of the system as possible, yet the pedal was lower and softer.....

I went down to visit my cousin at the shop and asked him for some of the hoses/fittings used for bench bleeding the master (I was going to re-bleed it that way) but I really felt I might be chasing a ghost as the brakes do work perfectly - it's just that the pedal is not as high or firm as it used to be.

My cousin listened to me describe the bleed procedure I had done and said, literally, that I was chasing a ghost. He said the reason the pedal felt softer was because the brakes were no longer being held on and that it was a confirmation I'd cased the issue. I think he's 100% correct. If there's any air left it's going to be a very small amount...

With respect to trace amounts of air being left, he said drive it for a week, let the air migrate through the system and then crack all the bleeders at that point - if I wanted to be 100% certain there is no air left.

Originally I thought that I would not be able to confirm this issue as 'case closed' due to the intermittent nature of the problem but I think my cousin hit the nail right on the head when he said the pedal should be softer. He likened it to a car with sticky calipers where the pedal is always high and hard and when the calipers are replaced it tends to be lower/softer because the calipers are now free to move.

My conclusion: Case closed. Realistically, we had taken everything out of the equation except for the possibility of a software error on the part of GM (had the pressure modulator not addressed it). Given that the pedal feel and height has changed considerably leads me to believe it's a tactile/tangible sign that the issue has indeed been addressed. In a weeks time I will crack all the bleeders but I already know what I'm going to find - nothing more then the peace of mind that comes from knowing that all the air has indeed been removed from the system :)

So there you have it. Just to recap this thread in one post;

The original issue was that both front brakes were intermittently being applied at the same time during normal driving conditions
The vehicle had no codes whatsoever
The caliper pistons were checked to ensure they weren't seized/seizing - they were free
The caliper slides were checked to ensure they were free - they were
Given that this occurred intermittently to BOTH front brakes at the same time brake hose failures were immediately ruled out
The master cylinder (and the booster and adjustment rod) were ruled out because I was able to get the vehicle to exhibit the problem in the car port and removing the lines to the master cylinder did not free up either wheel (therefore, the pressure must be applied from lower in the system)
Lastly, given that we know that the pressure is not being held to the front brakes from the brake hoses down, and, given that the master cylinder and everything above it is not holding the brakes on, the only component left is the brake pressure modulator.
And finally, concerns were raised that the brakes could be held on by one of the on-board management systems however this was taken off the table by two facts - one, none of those systems were engaged when the vehicle exhibited the problem, and two, when the vehicle exhibited the problem in the car port the ignition was turned off and yet the front brakes remained on. (those systems were not powered up).

So, if anyone encounters the same issue - that's a quasi-troubleshooting flowchart you can follow. Either way, we now know for a fact that the brake pressure modulator can actually cause these issues to occur.

This is an awesome thread with an awesome write up. Wish you were closure to me as I'd make you my go to mechanic.
 

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'03 Cadillac CTS
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Discussion Starter #42
Thanks Briggy - I appreciate the help you've provided through the thread as well :thumbsup:

What surprises me is that I was certain I'd never get real closure from the issue because I didn't foresee the change in the brake pedal travel and feel. When my parents got back into it (it's their car) they immediately noticed the difference and they like it a lot better. So now they know that it has in fact changed and that the issue is solved.

Prior to that understanding we figured the only way we'd know for certain is if the car never did it again. Now that there's a tangible difference we're certain it's cased :yup:
 

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Discussion Starter #45
It did come back (believe it or not) and it happened on the exact same trip at the exact same locations. So, clearly, the issue was NOT cased by replacing the Brake Pressure Modulator - even though everything pointed to it as the most likely candidate and we thought we had it beat.

However, this time, instead of pulling over and waiting for the brakes to cool I continued on to my cousin's shop with it making noise like you wouldn't believe and, as luck would have it, he had an open hoist for me to use.

Due to the intermittent nature of this issue (and it's generally bizarre presentation) he wanted to see it for himself so he duplicated the steps I had already taken by cracking the lines at the master to see if the front wheels would release - they didn't. You could not turn either wheel by hand.

I followed up on this by opening the bleeder on the driver's wheel and what did I find? The wheel did NOT release.

I then went over to the passenger side wheel and opened the bleeder - same thing.

My cousin was in shock when he saw this. This means that the calipers themselves are sticking and holding the front brakes on (no hydraulic pressure is applied with the bleeders wide open).

What floored him though is this fact. The problem is intermittent and when it occurs BOTH front calipers drag at the SAME time. In like manner, once they cool off they both release (at the same time) and then the issue is gone until whenever it decides to arise again.

The rear brakes were, once again, fine. The problem is isolated to the fronts. So, as unlikely as it seems, the only conclusion we can come down to is that both front calipers are prone to sticking, intermittently, at the same time.

It doesn't make sense (he advised me that with luck like that I should be playing the lotto) and we can't really understand why this is occurring. Previous to replacing the Brake Pressure Modulator I had taken the front brakes off and thoroughly cleaned them even though it was not required (both calipers were free as were the pads). To give you an idea;

- I cleaned the stainless pad holders such that there was zero dirt,rust/corrosion on them
- I cleaned and lubed the caliper pin that the caliper slides on (even though it was as free as can be and did not require it)
- I cleaned the parts of the pads that contact both the caliper piston and the ends up the pads that ride in the stainless slots.
- I pushed the caliper pistons back into their bore's with a c-clamp (the same one I've used for years on hundreds of brake jobs) while watching/feeling very closely for ANY obstruction or resistance. Nothing - not a damn thing. The pistons were sooth and required light pressure (similar to new calipers)

At that point I determined that everything was free and as loose as a goose. I then lubed the slide and the ends of the pads and the rear of the pads with SilGluide (special silicon brake lube) designed for just such a purpose.

At that point I wrote off the calipers as a potential cause for the reason that they were clean & free before I cleaned them and that I had manually done due diligence by breaking at down and re-cleaning/lubing the components with no signs of resistance anywhere to be found.

After all, since when do calipers, as a pair, intermittently drag at the exact same time? If anyone can answer that one I'd be impressed.

The only hypothesis we could come up with (and all the journeymen came around to see this thing) was that because the caliper is aluminum and the piston is not then perhaps heat causes a differential in the expansion of the dissimilar materials causing BOTH calipers to drag intermittently (when the brakes heat up).

The thing is, I road-tested this thing extensively prior to ordering the BPM and that included getting the brakes really hot. I beat on it repeatedly in an effort to induce the issue. I was only successful in getting the issue to arise once and at that time I had written off the calipers as a potential cause due to both my checking them and that the problem occurred intermittently at both wheels at the same time.

I have seen many cases where both calipers were always sticky, where one caliper (or the other) was always sticky, where one was intermittently sticky (and pulling the car to one side under breaking) or various combinations of that. But what I've never seen, and could never conceive possible is that both front calipers (only) could intermittently drag at the same damn time as well as release at the same time.

What's interesting to note is that when the journeymen came 'round to see this really weird issue I mentioned to them that years ago, when I was in the trade, Chrysler had created a steel caliper with a phenolic resin piston. It caused enormous problems and it was widely known in the trade that when you encountered these calipers (whether faulty or not) you replaced them with reman units that contained the more standard steel piston.

At that point I had assumed that the Cadillac caliper was aluminum and the piston was steel. When I got home and ordered up some reman calipers I found that the listing showed that they (proudly) came with the OEM phenolic resin pistons :-(

So, it appears that this CTS is using those plastic pistons. Had I known that when I was originally in the front brakes I would surely have replaced them being that I clearly remember the 'phenolic resin' mistake that Chrysler made all those years ago.

Nevertheless, if anyone can offer up some insights into how/why both front calipers would intermittently drag to the extent that you can't turn the wheels by hand, at the same time, I would sure like to hear it because now I'm really interested in this issue.
 

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2003 CTS 3.2/2004 GTO/2004 GMC Yukon
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I am not surprised by this..... don't take this the wrong way at all... I am ASE certified in brakes and steering and suspension. Do I know everything there is to know about brakes, steering and suspension? No, but I had a feeling that the mod pump wasn't the problem. Usually when those go bad, when you apply the brakes, the pedal will kick back at you as if there was a rubber ball between the pedal and the floor. I did initially rule out both calipers being bad because it is just weird that both would do it at the exact same time. Even harder is trying to explain it to the customer.... they think you are trying to rip them off. Anyway, when someone comes into the shop with an issue like this, or I am doing a brake check, I will take a c-clamp and squeeze the caliper piston back with the caliper still attached. If there is unusual resistance, then I suspect a caliper that sticks. Uneven brake pad wear is usually a symptom. You can free the calipers by opening the bleeder screw and gravity bleeding. If the caliper pistons aren't welded to the calipers, they will free up, as you already know through your diagnosis. Yes, it is weird that it happened to both calipers as the same time, unbelievable, but it is possible. There really is no concrete answer to give you regarding why both calipers did it at the same time. What I can suggest is that if the core charge isn't too bad on the reman'd calipers, keep your stockers, open them up and see what failed. You may see corrosion and buildup in the caliper bores that is not allowing the piston to return freely. Brake fluid that is not changed on a regular basis can cause this. People that don't open up brake bleeders prior to squeezing the caliper piston back into the bore can inadvertantly jam a piston up because the sediment that is resting in there has no place to go so it remains in the bore, with potential to cause future problems.

You're diagnosis procedures, I will say, were awesome. I wish more technicians thought like you did during this process. There woud be more cars fixed right the first time. I am still learning.... I only work in a shop part time on the weekends. I work 7 days a week and am trying to leave my main job, a tractor trailer driver hauling chemicals and hazardous waste, and go full time into automotive repair. In the 2.5 years I have been working weekends, I have grabbed two ASE certs, mobile A/C certification and have gone from knowing next to nothing about suspensions to now diagnosising, replacing, and wheel alignment. I love it and can't wait to get there full time. Again, I can't answer why both calipers did it at the same time and at the exact same locations that this happened, but it did. I wish I could have given better advice but sometimes I can't think straight with the long hours I put in and a two and half year old that wants my undivided attention. Again, your ideas and diagnosis are simply spot on... I would just chalk this one up to total rareness. The only thing I can think of is that if you open up the calipers, you may find distorted plastic pistons that have been degraded over time, on both sides, that will cause the intermittant sticking. Glad you found the problem once and for all.
 

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Discussion Starter #47
Thanks Goat - no worries about your thinking it wasn't the modulator pump assembly. For myself, I don't feel bad about it as I had done as much research on it as could possibly be done, and we're in agreement about rarity of calipers presenting this way.
That was a great post, by the way!

With respect to why it happened on the exact same trip and at the exact same spot - it must be that my driving style and the conditions on that trip happen to cause the issue to show up. Perhaps the brakes get to just the right condition for the problem to present.

I think your idea of breaking apart the calipers is a good one and historically I've never an issue with core charges when I strip things down so I will definitely pull 'em apart, photo them, and post up the pics.

Prior to going the abs pump route I had taken the calipers off and pushed all 4 pistons back into their bores and they were smooth as silk. That's why I ruled them out right off the bat. In addition, break pad wear on all 4 pads was perfect. So there was no indication at all that anything was even remotely worn. This is why I ruled out calipers but the clencher was that calipers don't, as a rule, intermittently drag, as a pair, at the same time.

That, combined with the fact that everything looked, felt & worked perfectly meant, to me, that the calipers could be ruled out completely. It was, and still is, my opinion that for both calipers to exhibit this behavior on an intermittent basis, as a pair, is very nearly impossible. And by that I mean that a person really should have a better chance at winning the lottery then seeing this kind of behavior on a repeatable, yet intermittent basis.

The fluid has been flushed (at least 3 liters through the system) so I'm certain that moisture/contamination is not an issue.

Nevertheless, given that when the car did this yesterday it once again occurred at both front wheels and this time, we got to find out that releasing the bleeders did not free up the wheels. Therefore, it has to be that the calipers are mechanically locked - no matter how rare or bizarre the presentation of the problem is.

I also ordered up a new set of brake hoses because if I'm winning the lottery with respect to both calipers intermittently dragging at the same time then it's entirely possible that I'm also going to win with something like brakes hoses doing something that's not physically impossible too - hahaha!

At any rate, I'll post back as we go along and I'm certainly going to pop the pistons and see what the old calipers look like on the inside. Thanks for the great post and the encouragement!
 

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Thanks Goat - no worries about your thinking it wasn't the modulator pump assembly. For myself, I don't feel bad about it as I had done as much research on it as could possibly be done, and we're in agreement about rarity of calipers presenting this way.
That was a great post, by the way!....


.....Nevertheless, given that when the car did this yesterday it once again occurred at both front wheels and this time, we got to find out that releasing the bleeders did not free up the wheels. Therefore, it has to be that the calipers are mechanically locked - no matter how rare or bizarre the presentation of the problem is.

I also ordered up a new set of brake hoses because if I'm winning the lottery with respect to both calipers intermittently dragging at the same time then it's entirely possible that I'm also going to win with something like brakes hoses doing something that's not physically impossible too - hahaha!

At any rate, I'll post back as we go along and I'm certainly going to pop the pistons and see what the old calipers look like on the inside. Thanks for the great post and the encouragement!

One thing to consider. You said you drove it to your cousins shop to show him the problem. Which means during that drive teh brakes were binding, and overheating. Is it possible that the sticking calipers were really from the over heating. As opposed to the original problem ? Just a thought.

Question when you bled the front calipers at the caliper, was the fluid pressurized or no ? My thinking is the calipers my have got bound up from the over heating. However the problem may still be upstream in the fluid line ? The answer to this would lay in whether the line was pressurized. No pressure = caliper problem. Pressure = upstream problem.

I'm with wicked your method was sound. Is there a solution for the plastic pistons .. ie replacement metal ones, or would you have to install whole new calipers ?
 

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Discussion Starter #49
One thing to consider. You said you drove it to your cousins shop to show him the problem. Which means during that drive teh brakes were binding, and overheating. Is it possible that the sticking calipers were really from the over heating. As opposed to the original problem ? Just a thought.
Good suggestion but I'd have to say no. There was no hard/extended braking on the drive, the ambient temperature was at 10c (0 is freezing) and the car has drilled and slotted rotors along with ceramic pads. In addition, it's got the optional 17" wheels that are, literally, wide open. So, an enormous amount of air goes through them. To give you an idea as to how well they dissipate heat, the rotors have not warped during any of these extended braking periods ;-)

Question when you bled the front calipers at the caliper, was the fluid pressurized or no ? My thinking is the calipers my have got bound up from the over heating. However the problem may still be upstream in the fluid line ? The answer to this would lay in whether the line was pressurized. No pressure = caliper problem. Pressure = upstream problem.
When I cracked the bleeders on the front brakes when the wheels were still locked there was zero pressure. This would indicate that the calipers themselves are mechanically being clamped on (stuck).

When I looked into reman calipers I found that all the listings available to me proudly included the blurb, "Comes with OE Phenolic Resin Piston". I then checked to see if I could buy pistons themselves (thinking I would re-build them myself and then change them over to a steel piston) only to find that I have zero listings for caliper parts for this vehicle. So what I did is order up a set of reman's (these ones come complete with the brackets - I couldn't find a listing without) and just for kicks I ordered up hoses too (even though they aren't causing an issue).

I would agree with your thoughts on heat causing them to drag but the thing is, I test drove this thing for an entire day (fully half a tank of gas) trying to get it to act up prior to ordering up the ABS Pressure Modulator. During that time I ranked on the brakes and got them cooking hot many times. I also simulated normal driving, highway driving, town driving, you name it. It was only at the very end of that test drive that, on my way home, it acted up.

At different times during that test drive I had the car up to maximum speed (speed limited?) and then nailed the brakes as hard as possible to bring it to a complete stop. I did this several times and all sorts of other things but it wasn't until much later that it acted up.

The two times it acted up coming back from the neighboring town are quite strange. There is no appreciable braking on that drive - it's almost entirely 'freeway' driving with 3 lights spread out over a 20 minute drive. So, at most, there is only a few brake applications and they tend to be light. As such, the brakes really should be stone cold during the entire trip unless you hit a light. So, to answer your question, it doesn't really seem to be related to heat. You can get them cooking hot and they won't do it and they will also do it when there has been light brake action.

What makes this even stranger is that all 4 pads are evenly worn. Either way, I think at this point it's important to keep holding on to the fact that cracking the bleeders did not result in the wheels being freed up. That does indicate that the calipers themselves are mechanically locked on no matter how strange the cause of it is. So out they go, along with the hoses, and then we'll see again. If the problem occurs again the car will be the next part changed, which is a shame, because it's largely perfect. It's probably one of the cleanest and otherwise trouble-free CTS's out there.
 

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Discussion Starter #50 (Edited)
Hi Folks - hopefully my last update on this job :bonkers:

The reman calipers showed up and one of the two had new pistons and one did not. I sent the one with the used pistons back and got another - same thing (used). In the end the warehouse only had one caliper left and it was doubtful that it would have new pistons so I just installed 'em.

The OEM Ceramic pads I installed a couple of years ago had heat cracks in them so I just went with what they had in stock which was Raybestos professional grade ceramic's.

Anyway, I installed new brakes hoses (just for the sake of completion) and the calipers/pads, bled the system and found that the pedal was mushy and the brake performance was sub-par (stopping distance was roughly twice what it was before the job). Brought it back home and went to remove the wheels to re-bleed the system (to ensure there really was no air) and promptly rounded off one of the stainless lug nut caps which ultimately resulted in a new cap and nut :thepan:

Re-bled the system, put the wheels back on and found the same thing. Spongy pedal and increased stopping distance. At that point (in a fit of frustration, after all, this is only brakes!) I went to see my cousin at the shop and he mentioned to me that he changed over from Raybestos to Wagner (as a general rule) due to the exact same issue - soft pedal. In fact, he had several customer complaints of soft pedal which, when he looked into it, cased by changing over the Wagner's. In the end he tracked it back to the metal shim on the backs of the pad - in simple terms the Raybestos pad's backing is more spongy resulting in a softer pedal and the Wagner's actually bond some of the pad material to the backside of the pad (I haven't seen this myself) and that results in a way firmer pedal.

He oughta know as he does an awful lot of brakes and has a lot of experience with different pads etc. So, I ordered up the OEM's that I had before (I liked 'em) and then popped 'em in today.

Point of interest (other the pad/pedal/performance issue with the Raybestos pads) is that the new OEM ceramic's have re-designed caliper abutment clips. The new design features a new rubberized backing designed to eliminate rattles and such. It's a very slick setup and I could see that it would be WAY better then the original design clips.

Problem is, once again, shipping damage killed my new design clips. The clips are put in a bag and then thrown in the box with the pads. The pads are clumped together in a vacuum sealed type wrapper. That means the as the package is in transit the pads move around inside the box and bent the clips :helpless: Trying to bend them back into shape results in broken clips :helpless:

So, in the end I could see the new design clips, appreciate them but not install them because of the way GM puts the package together (I've been here before with the Brake Pressure Modulator and shipping damage).

Anyway, long story short, changing out the Raybestos pads and re-installing the identical OEM pads I had used before resulted in an immediately firmer brake pedal (literally as hard as a rock) before I even hit the road for a test drive. Not only that but the brake performance (with respect to stopping distance) halved right off the bat. The OEM pads are noisier (due to the drilled/slotted rotors) but that doesn't really matter to me. I'm just glad we're back to the land of performance brakes with the corresponding pedal to go with it (I really couldn't stand the pillow pedal that came with the aftermarket pads).

Anyway, here's some parting shots (so to speak!) BTW, check out the rubberized clips - they are the smartest thing I've seen in some time - wish I could have used them!



New brake hose, caliper, OEM pads and, in the background, you can just see the brake pressure modulator



The re-designed new clips (complete with bends from shipping damage)



The backside of the new clips - note the rubberized coating to prevent clicks, squeaks and what have you - very cool. Note also the bent tabs that rendered them unusable...



Just some of the shipping damage :nono: Trying to repair it was useless as the clips break as soon as you bend them back into shape :thepan:

Last thoughts, I ended up with new clips that came with the calipers. These seemed to be identical to the OEM ones that came with the last set of OEM pads I installed a couple of years ago. The Raybestos replacement pads came with clips that were identical in shape but clearly made of a different material. They looked/felt cheaper and so I didn't use them. The OEM clips with the latest OEM pads were the re-designed units - I can't recommend using the OEM ceramic pads enough. For the most part Raybestos has been good to me but the difference between the two (in this case) was night and day. For the record, the OEM ceramic pads I used were A/C Delco D921CH - the only issue with them is that they seem to, if anything, slow the car down too fast although one can easily adjust their braking habits to compensate. It's also worth noting that the D921CH's were on the car every time the brakes heated up and so they were subjected to extreme temps at least 5 times that I know of and I did measure the new OEM's against the old ones and found that after 3 years and several sticking caliper incidents the old pads were worn less then 1mm from the new ones..... I find that to be remarkable performance. Were it not for the heat cracks I never would have changed them.

Lastly, it was mentioned that I should pop the pistons out of the old calipers and inspect them to try and determine exactly why both calipers were intermittently sticking at the same time. I did pop one piston out and did not see any damage of significance to either the bore or the piston. I know, 1 out of 4 is no way to check for the cause but, quite frankly, I'm sick of doing brakes on this car. I'm just holding fast to one fact which is that when I released the bleeder screws on both calipers (when the intermittent dragging was occurring) neither caliper let go. That's got to mean that the calipers were mechanically stuck no matter how rare/odd/strange it was that both would intermittently (and repeatedly) stick at the same time.

Case closed!
 

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Hi Folks - hopefully my last update on this job :bonkers:

The reman calipers showed up and one of the two had new pistons and one did not. I sent the one with the used pistons back and got another - same thing (used). In the end the warehouse only had one caliper left and it was doubtful that it would have new pistons so I just installed 'em.

The OEM Ceramic pads I installed a couple of years ago had heat cracks in them so I just went with what they had in stock which was Raybestos professional grade ceramic's.

Anyway, I installed new brakes hoses (just for the sake of completion) and the calipers/pads, bled the system and found that the pedal was mushy and the brake performance was sub-par (stopping distance was roughly twice what it was before the job). Brought it back home and went to remove the wheels to re-bleed the system (to ensure there really was no air) and promptly rounded off one of the stainless lug nut caps which ultimately resulted in a new cap and nut :thepan:

Re-bled the system, put the wheels back on and found the same thing. Spongy pedal and increased stopping distance. At that point (in a fit of frustration, after all, this is only brakes!) I went to see my cousin at the shop and he mentioned to me that he changed over from Raybestos to Wagner (as a general rule) due to the exact same issue - soft pedal. In fact, he had several customer complaints of soft pedal which, when he looked into it, cased by changing over the Wagner's. In the end he tracked it back to the metal shim on the backs of the pad - in simple terms the Raybestos pad's backing is more spongy resulting in a softer pedal and the Wagner's actually bond some of the pad material to the backside of the pad (I haven't seen this myself) and that results in a way firmer pedal.

He oughta know as he does an awful lot of brakes and has a lot of experience with different pads etc. So, I ordered up the OEM's that I had before (I liked 'em) and then popped 'em in today.

Point of interest (other the pad/pedal/performance issue with the Raybestos pads) is that the new OEM ceramic's have re-designed caliper abutment clips. The new design features a new rubberized backing designed to eliminate rattles and such. It's a very slick setup and I could see that it would be WAY better then the original design clips.

Problem is, once again, shipping damage killed my new design clips. The clips are put in a bag and then thrown in the box with the pads. The pads are clumped together in a vacuum sealed type wrapper. That means the as the package is in transit the pads move around inside the box and bent the clips :helpless: Trying to bend them back into shape results in broken clips :helpless:

So, in the end I could see the new design clips, appreciate them but not install them because of the way GM puts the package together (I've been here before with the Brake Pressure Modulator and shipping damage).

Anyway, long story short, changing out the Raybestos pads and re-installing the identical OEM pads I had used before resulted in an immediately firmer brake pedal (literally as hard as a rock) before I even hit the road for a test drive. Not only that but the brake performance (with respect to stopping distance) halved right off the bat. The OEM pads are noisier (due to the drilled/slotted rotors) but that doesn't really matter to me. I'm just glad we're back to the land of performance brakes with the corresponding pedal to go with it (I really couldn't stand the pillow pedal that came with the aftermarket pads).

Anyway, here's some parting shots (so to speak!) BTW, check out the rubberized clips - they are the smartest thing I've seen in some time - wish I could have used them!



New brake hose, caliper, OEM pads and, in the background, you can just see the brake pressure modulator



The re-designed new clips (complete with bends from shipping damage)



The backside of the new clips - note the rubberized coating to prevent clicks, squeaks and what have you - very cool. Note also the bent tabs that rendered them unusable...



Just some of the shipping damage :nono: Trying to repair it was useless as the clips break as soon as you bend them back into shape :thepan:

Last thoughts, I ended up with new clips that came with the calipers. These seemed to be identical to the OEM ones that came with the last set of OEM pads I installed a couple of years ago. The Raybestos replacement pads came with clips that were identical in shape but clearly made of a different material. They looked/felt cheaper and so I didn't use them. The OEM clips with the latest OEM pads were the re-designed units - I can't recommend using the OEM ceramic pads enough. For the most part Raybestos has been good to me but the difference between the two (in this case) was night and day. For the record, the OEM ceramic pads I used were A/C Delco D921CH - the only issue with them is that they seem to, if anything, slow the car down too fast although one can easily adjust their braking habits to compensate. It's also worth noting that the D921CH's were on the car every time the brakes heated up and so they were subjected to extreme temps at least 5 times that I know of and I did measure the new OEM's against the old ones and found that after 3 years and several sticking caliper incidents the old pads were worn less then 1mm from the new ones..... I find that to be remarkable performance. Were it not for the heat cracks I never would have changed them.

Lastly, it was mentioned that I should pop the pistons out of the old calipers and inspect them to try and determine exactly why both calipers were intermittently sticking at the same time. I did pop one piston out and did not see any damage of significance to either the bore or the piston. I know, 1 out of 4 is no way to check for the cause but, quite frankly, I'm sick of doing brakes on this car. I'm just holding fast to one fact which is that when I released the bleeder screws on both calipers (when the intermittent dragging was occurring) neither caliper let go. That's got to mean that the calipers were mechanically stuck no matter how rare/odd/strange it was that both would intermittently (and repeatedly) stick at the same time.

Case closed!
nice work, by the way you must have pissed of the gremlins man, ... cause you have no luck lol.
 

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nice work, by the way you must have pissed of the gremlins man, ... cause you have no luck lol.
You got it. I've never seen so many parts arrive with shipping damage before. I've never seen calipers do this before. I never knew about the Raybestos pads issue before. This job went on, and on, and on, and on.

Right after doing this job I bit the bullet and replaced the rad on my own car. I had replaced it about 3 years back with a new one. The reason for replacing an already replaced rad? When I installed the new one 3 years back I found that it leaked intermittently around the lower rad hose. I tightened it up and waited to see. Eventually it leaked again. However, I could never pin it down because it was also intermittent and it was a small leak. It seemed to only leak at certain temperatures.

By the time I figured out that it was the gasket between the plastic tank and the radiator core the warranty on it had expired. Nice. No rad shop around here would replace the gasket for me :) After the Cadillac I thought I should go after that one too and be done with them all :)

But you're right - there's been little luck with respect to myself and mechanical devices lately. It's time to move on :)
 

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We are getting a 67k mile CTS and it has had this strange intermittent vibration issue. You drive at constant speed and after 20 min or so it starts this terrible vibration in the front steering wheel and then it vanishes with no change in speed, etc. Well, the car is out of town at a relatives and will become part of our family. They had the original pads and rotors were just replaced and on the maiden voyage the front brakes were literally smoking. The shop now says the calipers are sticking. It reads almost exactly as the problem described here except that the right rear is also doing it.
 

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Just in case anyone finds this thread and is looking for another outcome, all 4 calipers were sticking. We swapped them out, replaced rotors and pads as well and zero issues since.
 

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I've read through the Posts about this issue and have heard quite a few ideas. But was there ever a definitive "Cure" for this particular problem? I seem to be experiencing this issue right now.

Thanks!
 

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I know this is an old thread but I was having the exact same problem.

Problem solved.

I replaced all of my brake lines, due to rust and had the same problem. Bled brakes more times than I can count. Replaced front calipers, rotors and pads. Replaced all brake pad hardware (pins and spring plates). Pulled abs fuse...... Nothing worked.

Finally replaced brake booster. FIXED! It looks like it was hanging up internally and not returning all the way. There is evidence of an old matter cylinder lead down the front of the brake booster.

Now I am debating putting the old front calipers on back of the car.

I would have never thought brake booster for this kind of failure.......

I hope this helps someone else.
 

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I know this is an old thread but I was having the exact same problem.

Problem solved.

I replaced all of my brake lines, due to rust and had the same problem. Bled brakes more times than I can count. Replaced front calipers, rotors and pads. Replaced all brake pad hardware (pins and spring plates). Pulled abs fuse...... Nothing worked.

Finally replaced brake booster. FIXED! It looks like it was hanging up internally and not returning all the way. There is evidence of an old matter cylinder lead down the front of the brake booster.

Now I am debating putting the old front calipers on back of the car.

I would have never thought brake booster for this kind of failure.......

I hope this helps someone else.
Was it just your front brakes hanging up? And had you tried loosening the lines at the master cylinder to see if that released your brakes? I ask because I'm trying to solve my own problem, and loosening the lines at the master cylinder did not release my front brakes, so I'm assuming it isn't anything before that point in the system.
 
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