Rear brakes dragging slightly

[FiatRunner]

Hello all,

My rear brakes have started dragging the past few days. Not very much, but enough for the brakes to squeak and get a bit warmer than the fronts. I actually noticed this because the handbrake all of the sudden "fixed itself". My handbrake previously did little to nothing at all, and now it is somewhat effective.

I am going to start by replacing the compensator, which is leaking and needs to be replaced anyway, but what else should I check? How do I tell if the rubber lines have swollen? Would they even be swollen if they were replaced 6 years ago, and only used for 10k miles? Did the caliper over-adjust itself? Can it do that?

I'd really rather try and fix things than simply replace parts with the hope that'll fix it.

Sorry, I realize that is a multitude of questions all at once. Any answers are appreciated.

[18Fiatsandcounting]

I am going to start by replacing the compensator, which is leaking and needs to be replaced anyway, but what else should I check? How do I tell if the rubber lines have swollen? Would they even be swollen if they were replaced 6 years ago, and only used for 10k miles? Did the caliper over-adjust itself? Can it do that?

There is a 5th brake hose that is often missed, the one from the metal brake line down the drivetrain tunnel to the "T" junction on top of the rear axle. It's fairly common to replace the four lines to the calipers but forget this 5th one. Over time, the inside can swell shut, causing the rear brakes to drag.

To my knowledge, the rear calipers can't over-adjust themselves.

-Bryan

[FiatRunner]

It's fairly common to replace the four lines to the calipers but forget this 5th one. Over time, the inside can swell shut, causing the rear brakes to drag.

To my knowledge, the rear calipers can't over-adjust themselves.

Good to know. I’ll check all of the lines, and I plan on putting new brake parts grease on the slides as well, they looked pretty dry.

I might also simply try stopping hard a few times. I don’t drive the car too hard and I wonder if a few real fast stops would loosen some things up. Who knows.

[TX82FIAT]

How long has the car sat between use? I could be the brakes just need to free p with use and you already mentioned lubing the slides. I'm not sure i would brake hard so much as brake often for a few miles to see if that works. If you have a leak, you may have air in the system contaminating the fluid, suggest fixing the leak and blead the brake fluid.

[FiatRunner]

I drive the car every day that the weather permits... which ends up being 6 or 7 days a week. Never overly hard or fast.

I greased the slides and drove it around for 10 or 12 miles, including a few hard stops. I think it's better, but there's a chance I'm just telling myself this.

I have ordered a new center brake hose, because why not? It's $12 and can't hurt. Unfortunately, I won't be able to install it for a week or so, because I am dropping off the car at a shop later today to have the suspension completely rebuilt. I'll update when I can.

[rridge]

If your parking brake cable is original or has a damaged rubber or plastic cover, it may have internal corrosion that is not allowing full release.

[FiatRunner]

I’ve got an update.

I ordered the new brake hoses, and they arrived, but as I was taking the wheels off and jacking the car up to replace them, I noticed there was some slack in the handbrake cable.

One of the crank arms on the caliper is stuck, and won’t retract all of the way. The cable isn’t the issue, it moves freely and easily.

How should I go about getting this unstuck? I’d much rather work on the handbrake cable than the actual brake hoses. I’d rather bleed the lines unless I need to.

[18Fiatsandcounting]

One of the crank arms on the caliper is stuck, and won’t retract all of the way. The cable isn’t the issue, it moves freely and easily.

The rear brakes on these cars are somewhat problematic in that the self-adjusting mechanism for the parking brake actuator stops working, and the handbrake works poorly as a result. The solution is a new caliper or rebuilding the old one. There are some subtleties to this, and it's often done incorrectly. Even by "competent" shops.

The other items that cause problems in the rear brakes are the rubber brake line in the center from the metal line in the tunnel to the top of the rear axle where there is a T-connector. This center brake hose is often missed, and often can collapse internally. The rear brake regulator (sort of a poor man's anti-lock brake device) also tends to cause problems as it ages. This generally can't be rebuilt, but new ones aren't that expensive.

-Bryan

[FiatRunner]

The rear brakes on these cars are somewhat problematic in that the self-adjusting mechanism for the parking brake actuator stops working, and the handbrake works poorly as a result. The solution is a new caliper or rebuilding the old one. There are some subtleties to this, and it's often done incorrectly. Even by "competent" shops.

I've replaced the brake compensator and center brake line, and bled the system multiple times. I'm near certain that the issue is the brake caliper sticking.

My question is: How difficult/risky is rebuilding a caliper? The rebuild kit is $6, and a new caliper is $75. Is a new caliper worth the $60 difference? As a student in college, every saved dollar is a tiny little step towards ending debt. Would I be able to rebuild a caliper without professional tools like a press? I just hate replacing original, OEM parts with something new, especially when that part can be rebuilt. But if it's really a pain... a new caliper wouldn't be a big deal at all.

Thank you!

[PaulC]

Not hard at all. Just follow the instructions in the service manual.
And be sure to make note of the orientation of the Belleville springs ( look like dished washers) on the threaded piston rod and the orientation of the long side of the notch at the top of the rod.
If its backwards the actuation lever will not be in the correct position when you assemble it.
This should help
https://mfm.mirafiori.com/faq/content/r ... lipers.htm

The calipers are pretty bullet proof castings and the internals the same. Make sure the piston and bore is smooth and not pitted.

[18Fiatsandcounting]

I concur with Paul that it's not too hard, but as he notes, the actuator rod and the associated "dished washers" that go with it can be tricky to reinstall. My method is to clamp the caliper in a vise and then use a very large set of slip-joint pliers to compress the actuator rod (and thus the washers) as I reinstall the little wedge that goes between the end of the rod and the groove in the actuator arm.

By the way, the correct orientation for the washers is (body of the caliper on the left):

| ) () ()

The flat washer is installed in the recess in the caliper, against the aluminum. There should be 5 Belleville washers installed as noted above. This is a frustrating operation, so it's fairly common to find calipers where someone has previously removed a washer or two to make it easier.

-Bryan

[FiatRunner]

Thank you both for the replies!

I'll buy a rebuild kit. Or maybe two, keep one on the shelf.

I'll post an update when I've got them installed.