Sticking rear caliper (HELP)
Thread Starter
Newbie
Joined: Nov 2018
Posts: 12
Likes: 0
From: Birmingham, Al
E 63 AMG
Sticking rear caliper (HELP)
I have a slight break dilemma. Sorry for the long message. I just wanted to be as detailed as possible.
I have a 2004 E320 with 52k miles on it. About 8 months ago I swapped out the Caliper and rotors for E55 AMG calipers and rotors. I bought all new caliper seals, piston boots, hardware, and pins from the dealer. I completely stripped the calipers and had them powder coated and I rebuilt them which was not hard at all.
I was driving and all of a sudden I felt heavy pulsating upon braking. When got off the interstate all I heard was a loud continuous squeal coming from the rear. When I made it home I used my infrared temperature gun to measure the temperature of each rotor. 3 measured within a few degrees of each other (170*). The rear passenger caliper measured 380* indicating possibly being seized.
I removed the hardware and pads and the piston moved back with ease. I then put the pads back in a pressed the brakes to extend the caliper pistons and all 4 came out with no issue. I also bled the caliper and it did seem to have some air bubbles.
I put everything back on and went on a test drive and everything was fine until and 30 minutes of brake testing. The same caliper is having I sticking issue. I don’t know what it is at this point. And I don’t thick the SBC pump is the problem. I can hear it activate and I don’t have any dash codes or errors.
I have a 2004 E320 with 52k miles on it. About 8 months ago I swapped out the Caliper and rotors for E55 AMG calipers and rotors. I bought all new caliper seals, piston boots, hardware, and pins from the dealer. I completely stripped the calipers and had them powder coated and I rebuilt them which was not hard at all.
I was driving and all of a sudden I felt heavy pulsating upon braking. When got off the interstate all I heard was a loud continuous squeal coming from the rear. When I made it home I used my infrared temperature gun to measure the temperature of each rotor. 3 measured within a few degrees of each other (170*). The rear passenger caliper measured 380* indicating possibly being seized.
I removed the hardware and pads and the piston moved back with ease. I then put the pads back in a pressed the brakes to extend the caliper pistons and all 4 came out with no issue. I also bled the caliper and it did seem to have some air bubbles.
I put everything back on and went on a test drive and everything was fine until and 30 minutes of brake testing. The same caliper is having I sticking issue. I don’t know what it is at this point. And I don’t thick the SBC pump is the problem. I can hear it activate and I don’t have any dash codes or errors.
MBWorld Fanatic!
Joined: Jan 2014
Posts: 3,966
Likes: 1,315
From: Republic of Texas
'99 and '05 E55 AMG
No codes? Replace caliper as lowest cost option. Inspect brake lines. Heck, just for grins and giggles, reinstall the original brake disc and caliper and see what happens. Yes, I realize that you would have different discs and calipers from left to right; this would be temporary to determine if it is the caliper or the rest of the brake system. If no issues after returning that corner to stock, I would reinstall the E55 brake rotor and a different caliper.
Air bubbles would not cause the caliper pistons to lock onto the brake rotor; if anything, they would allow the pistons to retract.
Air bubbles would not cause the caliper pistons to lock onto the brake rotor; if anything, they would allow the pistons to retract.
MBWorld Fanatic!
Joined: Jun 2020
Posts: 1,177
Likes: 314
2006 CLS55 AMG, 2005 SLK 350 AMG
Based on the age of the car I would suspect the rubber brake hose/line that connects to the caliper. Did you use any brake clean or any other non-brake fluid with the rebuild of the calipers and the system? If any non-brake fluid has been mixed with brake fluid you could have the problem conidtions you are having.
Thread Starter
Newbie
Joined: Nov 2018
Posts: 12
Likes: 0
From: Birmingham, Al
E 63 AMG
No codes? Replace caliper as lowest cost option. Inspect brake lines. Heck, just for grins and giggles, reinstall the original brake disc and caliper and see what happens. Yes, I realize that you would have different discs and calipers from left to right; this would be temporary to determine if it is the caliper or the rest of the brake system. If no issues after returning that corner to stock, I would reinstall the E55 brake rotor and a different caliper.
Air bubbles would not cause the caliper pistons to lock onto the brake rotor; if anything, they would allow the pistons to retract.
Air bubbles would not cause the caliper pistons to lock onto the brake rotor; if anything, they would allow the pistons to retract.
Thread Starter
Newbie
Joined: Nov 2018
Posts: 12
Likes: 0
From: Birmingham, Al
E 63 AMG
Based on the age of the car I would suspect the rubber brake hose/line that connects to the caliper. Did you use any brake clean or any other non-brake fluid with the rebuild of the calipers and the system? If any non-brake fluid has been mixed with brake fluid you could have the problem conidtions you are having.
MBWorld Fanatic!
Joined: Jun 2020
Posts: 1,177
Likes: 314
2006 CLS55 AMG, 2005 SLK 350 AMG
The E55 uses DOT 4+ brake fluid. This is due to having the electronic braking system. Does your E320 have conventional braking system or does it also have the electronic braking system? When you changed the calipers and disconnected the rubber line from the caliper, was brake fluid dripping out of the rubber line until you had it reconnected to the new capiler? If the rubber line is not clogged then there would have been continous fluid coming out of the line while it was disconnected. If not, then the line would be clogged and is an issue with insufficient regular brake fluid flushing and replacement.
Thread Starter
Newbie
Joined: Nov 2018
Posts: 12
Likes: 0
From: Birmingham, Al
E 63 AMG
My car is equipped with an SBC pump and also uses DOT4+ brake fluid. When I got all of the parts I also ordered new brake hoses just as a precaution, but the factory lines looked great with no cracks or brittleness. when I disconnected the lines there was a steady flow of fluid releasing from all of them. Everything has worked great over the past 8 months up until recently. Even just yesterday, I bled the caliper, and the fluid drained with no issue. I am also able to move the caliper pistons with ease. I'm going to remove the caliper next and break it down again to see if the piston rings are still good. The main issue is that the caliper pistons aren't retracting causing it to drag on the rotors thus making heat.
Trending Topics
MBWorld Fanatic!
Joined: Jun 2020
Posts: 1,177
Likes: 314
2006 CLS55 AMG, 2005 SLK 350 AMG
My car is equipped with an SBC pump and also uses DOT4+ brake fluid. When I got all of the parts I also ordered new brake hoses just as a precaution, but the factory lines looked great with no cracks or brittleness. when I disconnected the lines there was a steady flow of fluid releasing from all of them. Everything has worked great over the past 8 months up until recently. Even just yesterday, I bled the caliper, and the fluid drained with no issue. I am also able to move the caliper pistons with ease. I'm going to remove the caliper next and break it down again to see if the piston rings are still good. The main issue is that the caliper pistons aren't retracting causing it to drag on the rotors thus making heat.
If the lines are clear, but there is still an issue of the caliper not relasing, I'm wonding if you had to do any modifications to mount the non-stock calipers? Some of the AMG calipers use larger diameter mounting bolts than what your stock calipers used? Was that the case in your situation? If so, how did you address that situation?
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
