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'03 STS, '99 SLS (sold), '02 Yukon, '02 Z28
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Discussion Starter · #1 ·
Do you compress or screw the piston back in
 

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2003 Cadillac Seville STS 73k Miles, '90 Chevy 1500 Reg Cab
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725 Posts
Compress, according to FSM don't compress more than 1mm on rear caliper due to potential damage to internal adjusting mechanism and/or integral park brake mechanism. Torque for the rear brake caliper pin bolt is listed at 27 Nm or 20 lb ft.
 

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'03 STS, '99 SLS (sold), '02 Yukon, '02 Z28
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77 Posts
Discussion Starter · #3 ·
so the piston does not need to be flush with the piston housing like the fronts?
 

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'03 STS, '99 SLS (sold), '02 Yukon, '02 Z28
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77 Posts
Discussion Starter · #4 ·
Alright. Now I am stumped. Opened bleeder valve to allow the caliper fluid to escape and tried to compress the piston with a caliper piston compressor. On both rears, the piston only goes in a smidgen. The piston has to go in to allow for New pads and rotors. WHAT AM I DOING WRONG? Don't tell me both rears are frozen. Is there a release for the parking break mech.
 

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2002 F55 STS, 2014 Explorer XLT, F-150s
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This is the third rear caliper question concerning this problem in a week - and it's all answered elsewhere, BUT:

The rear caliper pucks are also part of the parking brake system. They mechanically ratchet to compensate for brake pad wear. To return them to their "new" position they must be screwed back into the caliper and the indents aligned with the new brake pad face.

You can use a pair of needlenose to screw in the puck, or you can do it the easy way - go to a NAPA and get a "brake cube" - a neat little thingy with various faces used to screw in 6 different varieties of rear caliper pucks. It connects to a socket wrench handle. There's a picture in skiller's thread close by - the one on Seville vibrations. The cube pic is very recent - last 4 posts.
 

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2003 Cadillac Seville STS 73k Miles, '90 Chevy 1500 Reg Cab
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725 Posts
This is the third rear caliper question concerning this problem in a week - and it's all answered elsewhere, BUT:

The rear caliper pucks are also part of the parking brake system. They mechanically ratchet to compensate for brake pad wear. To return them to their "new" position they must be screwed back into the caliper and the indents aligned with the new brake pad face.

You can use a pair of needlenose to screw in the puck, or you can do it the easy way - go to a NAPA and get a "brake cube" - a neat little thingy with various faces used to screw in 6 different varieties of rear caliper pucks. It connects to a socket wrench handle. There's a picture in skiller's thread close by - the one on Seville vibrations. The cube pic is very recent - last 4 posts.
Hum.....missed that in the FSM, gonna have to reread that section
 

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'03 STS, '99 SLS (sold), '02 Yukon, '02 Z28
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77 Posts
Discussion Starter · #7 ·
I am assuming it is still a good procedure to open up the bleeder valve?
 

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'03 STS, '99 SLS (sold), '02 Yukon, '02 Z28
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77 Posts
Discussion Starter · #9 ·
I have searched for break system bleeding procedures but have come up empty handed. Can someone point me in the right direction?

I have bleed brakes before but on this on the peddle is not allowing me to push to the floor. Have the RR set up with a homemade one man bleeder kit and the valve is open.
 

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'03 STS, '99 SLS (sold), '02 Yukon, '02 Z28
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Discussion Starter · #10 ·
does the car need to be running? wouldnt think so
 

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'03 STS, '99 SLS (sold), '02 Yukon, '02 Z28
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Discussion Starter · #12 ·
Everything is on and the car is down. Did not get a chance to bleed the sys because the peddle would not go down.

Started it up and now I have no break peddle. The breaks engage but the peddle has to be on the ground. I don't know how any air could have found its way into the sys. I never gave it a chance.

Shut the car off and the peddle is back. Is there a reset procedure?
 

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'03 STS, '99 SLS (sold), '02 Yukon, '02 Z28
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77 Posts
Discussion Starter · #14 ·
Other than a service manual, because I don't have one, is there in writing as to the step by step procedures to doing a brake job on these cars?
 

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'03 STS, '99 SLS (sold), '02 Yukon, '02 Z28
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Discussion Starter · #15 · (Edited)
Small update. I cleared all codes and unplugged the master cylinder for a couple of seconds. Got some peddle back. Took it for a spin. Feels like the rotors are warped BAD! Going to check over the work and try to re-bleed.

One of the codes in history was:
RIM U1255 - Class 2 Communication Malfunction (Serial Data Line Malfunction)
 

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'03 STS 122K, '01 STS 161K - 3/3/11
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Did you clean the rotor/hub mating surface while the brakes were apart?

Did you use a torque wrench to put the tire back on?
 

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Cadillac Technician
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The pistons screw in.

It is critical that you position the grooves in the piston properly to mate with the pins on the brake pads when reassembling them, also be sure to orient the pads properly on reinstallation.
Finally you need to pump the pedal and apply and release the parking brake repeatedly to "adjust" the piston to the proper position before road testing.
If you now realize you skipped any of this, please start over.

You can open the bleeder screw when forcing the pistons back in, but it isn't required. The MC will accept the fluid but it may overflow if the level is high to begin with.
As for bleeding, unless you got air into the system it isn't necessary but you should have the fluid flushed once in a while to protect the system from moisture damage.
 

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2002 F55 STS, 2014 Explorer XLT, F-150s
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Cast iron rotors do not warp !!! You have either excessive runout from improper assembly, there are pad resin/material deposits on the rotor, or the wheel(s) is/are bent or have their own runout. Caliper, hub, rotor and wheel mounting surface cleanliness is critical to vibration-free ride and braking.

Either get a GM/Helm Factory Service Manual from eBay or www.helminc.com or subscribe your car to www.alldatadiy.com.

Other than reading past threads and others' recent brake jobs, there is no procedure posted: the 3 year/model groups of Seville/Deville/Eldorado we work with in here all have somewhat different brake maintenance requirements.
 

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'03 STS, '99 SLS (sold), '02 Yukon, '02 Z28
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Discussion Starter · #19 ·
Cleaned all surfaces before, during, and after the install with 3M break cleaner. The wheels where torqued @ 30/60/100ftlbs.

I did orient the pistons to accept the pads. I am taking everything apart today just to double check. Did not engage the parking break.

Finally you need to pump the pedal and apply and release the parking brake repeatedly to "adjust" the piston to the proper position before road testing. If you now realize you skipped any of this, please start over.
Did pump peddle but it goes to floor each pump. Are you suggesting new equipment or just run through the paces again?
 

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2002 F55 STS, 2014 Explorer XLT, F-150s
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Until you reset and adjust the rear brake caliper pucks as described by ewill3rd you may well have excessive pedal travel: the ONLY reason you ever have a "hard pedal" is because the brake pads/shoes are clamped against the rotor/drum and the pedal can't go any farther: hydraulic fluid is incompressible, so if all's adjusted correctly you're sort of pressing the pedal against solid steel - there is practically no space between the pad and rotor in a properly adjusted system.
 
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