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Discussion Starter · #1 ·
Thought about doing this for some time, and finally couldn't take the pulsing rotors anymore so... I grabbed the bull by the horns! They look fantastic and stopping power is awesome! No more comments from the passengers as we wobble to a stop. :helpless: That warpage problem was so annoying! :bonkers:

It was a lot of fun too, and I am fortunate enough to have the software and machining center to do the cross-drilling of the rotors. Made a quick setup and machined them after work a while back, and had it all back together the next day. The strategy of the hole size and placement probably took me the most time, :suspect: as my rotors had an uneven number of ribs (41) and it was difficult to get a good looking pattern.

Here are a few pics of the process and results. The first one here is the rotor as I modeled it up in Solidworks to figure out the pattern. You cannot drill thru the ribs, and have to stagger the holes so the entire pad surface is used equally. Those gray lines on the surface are the aprox. pad wear area... ;)
 

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Discussion Starter · #2 ·
Ooops... Here is the graphic rendering!
 

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Discussion Starter · #3 · (Edited)
OK, now I seem to be able to post pics... :bouncy:
 

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Discussion Starter · #4 · (Edited)
Here is a picture of one of the rotors as I am drilling it on the CNC mill. I used a special 3-fluted .218 dia. carbide drill, and then followed up with a small carbide corner radius milling cutter to round the edges of all the holes.

I drilled through the first surface only, and then flipped them over and drilled from the other side. This way I could radius the other side with no alignment problems. :thumbsup:

I mirror-imaged the program at the machine control for the other rotor, so the pattern of holes is swept the opposite direction for the right vs. the left wheel... :yup:
 

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Discussion Starter · #5 ·
This is when I flipped it over and drilled the outside surface. Found it worked better to not spot -drill the holes first... Saved time that way too, took about 11 minutes per side! :sneaky: :yup:
 

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Discussion Starter · #6 ·
Here is the rotor installed on the Eldo. I am indicating to test for run-out of the rotor. These rotors were trued up real nice, had less than .003 run-out. The few nuts and washers are used to hold the rotor in place. :cool:
 

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Discussion Starter · #7 ·
This is some of the things required to service the pads and calipers. The bushings (rubber grommets) were badly worn and sticking. This is what was causing a lot of heat build up and warpage. :rolleyes2 They need to be pulled out (usually won't come out in one piece!), and slide the new ones in with a little silicone grease.

The pins were corroded pretty bad on the heads of the bolts, so I cleaned and polished them up as well. Threads may need to be cleaned up with a 11 x 1.5 die and re-tap the mounting holes to make it easier to thread the bolts back in. A small wire brush is very handy for cleaning inside caliper holes and rotor mounting faces... Assemble this with care not to get any grease on the braking surfaces, and use the brake cleaner spray if you do! :p
 

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Discussion Starter · #8 · (Edited)
Here is a view on a freshly painted assembly. Love the look of that freshly machined rotor with the silver and red! :coolgleam I used POR-20 heat resistant silver paint on the caliper, and Plasticote 500F engine paint of the back of the pads (masked off the pad surface) ;)

I forgot to mention, I re-used the existing pads, until I buy buy a set of ceramic low dust ones... The pads had a ton of life left on them, but were definitely wearing crooked. So I redressed them flat and parallel on a disc sander, and vapor blasted the backs to prep for painting...
 

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Discussion Starter · #9 ·
And the final result with the wheels back on.... Sweet! :coolgleam I'll bet it looks good on the road with the wheels spinning too! I can't wait to do the same to the back wheels now!

The best part of this whole project was I had so much fun doing it and it only cost me $20 rotor resurfacing, $9 for the bushings, and $4 for a can of paint! (I had the silver from doin' the mufflers earlier..)
 

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(rip 92deville rip 94 fwb) 97 ElDog
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so.... how much do u want to do mine :D
 

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Discussion Starter · #11 ·
juiceE said:
so.... how much do u want to do mine :D
Sorry JuiceE, not for hire! :rolleyes: I do wish I had this software and a machine like this at home, then I COULD do some side jobs like that... Hard enough to squeeze in my own stuff during lunch and after work! :helpless:

I also have to get moving on my 70 Firebird restoration project. Have already decided cross-drilled rotors are in the plan there too! :D

If you are looking to upgrade by purchasing new cross-drilled rotors, the Autospecialties Power Stop products look pretty nice. This is kind of what I modelled mine after. Here is a link to someones site who put them on his 97 SLS. Jason gives a lot of good info there about their product. :suspense:

http://jadcock.oldsgmail.com/cadsls/rotors.html
 

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1966 Fleetwood Brougham 2006 STS-4 1999 Deville Concours
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Very nice job! They look so good. Something to be said about..."the right tool for the job!" Can't wait to see all four complete. Good luck!
Paul
 

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I was thinking of slotting my rotors, not sure on what pattern and depth would be best. (I also have access to CNC Mill+Lathe). Need to find a way to make rotors last longer than a year...
 

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Discussion Starter · #14 ·
Thanks Paul, I really like the look too. Actually thought about painting the rear calipers today , but the wash machine broke down... :banghead: Will post a full side pic when I get it done! :cool:

etcCanuch, I originally thought about slotting mine also. The more I read, it sounded like the slotted rotors (usually a forward swept pattern like my holes) ate up the brake pads much quicker. There is more chance of cracking with holes vs. slotting, but keeping the holes smaller and breaking the edges with radii instead of chamfering helps reduce that chance. ;) If you do slot, I wouldn't go much deeper than the min. thickness of the rotor.

As far as the life of the rotors... I believe a lot of the life/warpage of rotors is due to poorly operating calipers and also cheap imported rotors. Make sure that your caliper pins and bushings are operating freely and lubricated with silicone grease. Especially here in winter climates with road salt this is a problem. You can easily check this without disassembly by clamping the piston back aways to produce some clearance between the rotor and pads, and then grabbing the caliper and see if you can easily slide it back and forth on the pins over that clearance. ;)

The cheaper imported castings have a lot of hard spots or inconsistant material, which can cause a pulsing even if it isn't warped or running out significantly. :rant2: I agree with our well-respected BBob who stated a while back that if you resurface used rotors you sometimes have less chance of warpage than throwing new ones on. This is because they have been heat-cycled and stressed relieved while in use, and are more stable once they have been on the car for some time... :thumbsup:
 

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They look great . Excellent job along with a your post :thumbsup: :thumbsup:


On a said note Eastwood makes a Hi Temp Brake Caliper and Drum Coating paint kit that comes in 9 colors. They look nice to . Link
 

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Discussion Starter · #16 ·
rollman said:
They look great . Excellent job along with a your post :thumbsup: :thumbsup:

On a said note Eastwood makes a Hi Temp Brake Caliper and Drum Coating paint kit that comes in 9 colors. They look nice to . Link
Thanks Rollman! Hey, those high-gloss finishes do look pretty nice. I can see that glossy silver with black pads on my Bucaneer Red Firebird! :yup: I'll keep that in mind when I get to that car's brakes. :coolgleam
 

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Sweet!

BTW, I installed powerstop crossed-drilled yesterday on all four corners and greatly appreciate the comments in the forum with regard to getting around the brake block tool needed to compress the rears!

Chris
99STS 95K
 

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Discussion Starter · #18 ·
cguthrie said:
Sweet!

BTW, I installed powerstop crossed-drilled yesterday on all four corners and greatly appreciate the comments in the forum with regard to getting around the brake block tool needed to compress the rears!

Chris
99STS 95K
Hi Chris,

Tried PM'ing you, but didn't work. I had replied to a different post of yours, but in case you didn't have it subscribed... I am looking for any info. or ideas on what hole pattern to put in my rear rotors now. What do your powerstop rears look like? Anything you can show/tell me would help. Thanks! :thumbsup:
 

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Spruce,

Took some photo's of the rear and front, probably won't be too helpful since the wheels are still on. Power Stop Rotors might have some better pics on their site.

What is interesting is that on the rears you can see what little swept area you really have. I chose the gold coating to minimize rusting. The pads immediately swept the coating of the area they cover. On the rears this does not even cover the cross drilling!

Could only get the rear photo attached to this message. /edit/not sharp enough to load the photo apparently!/

Terrific custom work, by the way,

Chris
99STS 98K
 

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Discussion Starter · #20 ·
cguthrie said:
Spruce,

Took some photo's of the rear and front, probably won't be too helpful since the wheels are still on. Power Stop Rotors might have some better pics on their site.

What is interesting is that on the rears you can see what little swept area you really have. I chose the gold coating to minimize rusting. The pads immediately swept the coating of the area they cover. On the rears this does not even cover the cross drilling!

Could only get the rear photo attached to this message. /edit/not sharp enough to load the photo apparently!/

Terrific custom work, by the way,

Chris
99STS 98K
Yup, I had my share of difficulties with attaching photos to this thread to... :hmm: If you could, can you just email them to me at [email protected] I would sure appreciate it.

Yes, that ni-cad plating doesn't take long to wipe off the rotors once the pads hit 'em! It is less than .0005 thick on the surface. They sure have come a long way with platings over the years though. The'll stay looking good for years! :coolgleam

Yes, I was thinking about how little those rear pads are, and what minimal contact area there really is... :rolleyes2 I'm quite sure there is not gonna be too many holes in that set, maybe 24-30?
 
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