Pete165
Active Member
- Joined
- June 21, 2013
- Messages
- 79
- Reaction score
- 13
- Location
- Chicago Burbs
- City, State
- Illinois
- Year, Model & Trim Level
- 2017 Sport
Below is how I fixed my rear calipers to prevent the parking brake from dragging, and also fixed a spongy low pedal in the process. This is on a 2017 Sport which has the heavy-duty brakes as standard, but I would imagine all trims and years from this generation would be the same or similar. I'm not sure what the non-heavy-duty setup looks like though. Hope this helps somebody...
Background: I was already aware of the rear caliper sticking being a common issue and I had to replace them on my previous '13 Limited, so I was not surprised to have to replace them on my Sport. I live near Chicago so winters are a factor with road salt, snow, and freezing temps. The 'new' calipers were your typical Autozone re-manufactured. So, back in may I replaced both rear calipers. The passenger side parking brake was stuck in a slightly-engaged position for an unknown length of time, and the pad was down to almost nothing. The driver side was not stuck but was severely corroded so I decided to just replace both. Fast-forward to July and I found that the passenger side caliper slide pins were loose and made a 'clunk' when I braked, so I replace the passenger caliper again (under warranty). Fast-forward to August and I find that the passenger caliper piston seal is leaking, so I AGAIN replace that caliper. This time I put everything together, power-bleed it again, and the pedal ends up mushy and very low. I try re-bleeding.. same issue. After a lot of swears and many more dollars in brake fluid (DOT-4 LV ain't cheap!) I found that the passenger side parking brake was sticking on the brand new (re-man) caliper!!! I fiddled with the mechanism and the nut that holds the arm, but the spring just didn't have enough strength to fully retract the arm. It need just a little more oomf. Now I could have gone and tried a 4th caliper, but how long would that one last? I already knew that the poor design of the parking brake mechanism was the problem.
Fix:
I added a couple extension springs that connect the parking brake arm to the lower caliper bolt, which gives the original return spring some help. I'm now confident that the parking brake will not stick unless it becomes severely corroded. This also fixed the spongy and low pedal because the piston is now fully retracting after disengaging the parking brake. I bought the parts I needed from McMaster-Carr near me, but I'm sure you could find the same parts or a different solution elsewhere. There's probably other ways of accomplishing this too. I thought of just buying a heavier torsion spring to replace the one that's on there, but I feel this is better because the leverage is now pulling the arm straight down.
Parts List:
Zinc Yellow-Chromate Plated Class 10.9 Steel Screws. (Flanged Hex Head, M8 x 1.25mm, 25mm Long)
Washer-Style Tag Holders for 5/16" Screw Size, 5/8" Wide
302 Stainless Steel Extension Springs with Hook Ends 2" Long, 0.75" OD, 0.075" Wire Diameter
302 Stainless Steel Extension Springs with Hook Ends 1.375" Long, 0.5" OD, 0.063" Wire Diameter
You could probably get away with the single 2" spring, but I bought a few sizes initially so I figured I would use these two together. A little extra pull doesn't hurt.
Pictures:
(I ended up using a zinc plated screw instead of the black-oxide screw in the pictures)
Background: I was already aware of the rear caliper sticking being a common issue and I had to replace them on my previous '13 Limited, so I was not surprised to have to replace them on my Sport. I live near Chicago so winters are a factor with road salt, snow, and freezing temps. The 'new' calipers were your typical Autozone re-manufactured. So, back in may I replaced both rear calipers. The passenger side parking brake was stuck in a slightly-engaged position for an unknown length of time, and the pad was down to almost nothing. The driver side was not stuck but was severely corroded so I decided to just replace both. Fast-forward to July and I found that the passenger side caliper slide pins were loose and made a 'clunk' when I braked, so I replace the passenger caliper again (under warranty). Fast-forward to August and I find that the passenger caliper piston seal is leaking, so I AGAIN replace that caliper. This time I put everything together, power-bleed it again, and the pedal ends up mushy and very low. I try re-bleeding.. same issue. After a lot of swears and many more dollars in brake fluid (DOT-4 LV ain't cheap!) I found that the passenger side parking brake was sticking on the brand new (re-man) caliper!!! I fiddled with the mechanism and the nut that holds the arm, but the spring just didn't have enough strength to fully retract the arm. It need just a little more oomf. Now I could have gone and tried a 4th caliper, but how long would that one last? I already knew that the poor design of the parking brake mechanism was the problem.
Fix:
I added a couple extension springs that connect the parking brake arm to the lower caliper bolt, which gives the original return spring some help. I'm now confident that the parking brake will not stick unless it becomes severely corroded. This also fixed the spongy and low pedal because the piston is now fully retracting after disengaging the parking brake. I bought the parts I needed from McMaster-Carr near me, but I'm sure you could find the same parts or a different solution elsewhere. There's probably other ways of accomplishing this too. I thought of just buying a heavier torsion spring to replace the one that's on there, but I feel this is better because the leverage is now pulling the arm straight down.
Parts List:
Zinc Yellow-Chromate Plated Class 10.9 Steel Screws. (Flanged Hex Head, M8 x 1.25mm, 25mm Long)
Washer-Style Tag Holders for 5/16" Screw Size, 5/8" Wide
302 Stainless Steel Extension Springs with Hook Ends 2" Long, 0.75" OD, 0.075" Wire Diameter
302 Stainless Steel Extension Springs with Hook Ends 1.375" Long, 0.5" OD, 0.063" Wire Diameter
You could probably get away with the single 2" spring, but I bought a few sizes initially so I figured I would use these two together. A little extra pull doesn't hurt.
Pictures:
(I ended up using a zinc plated screw instead of the black-oxide screw in the pictures)
