91 SHO brakes sticking

[Irish Pride]

I have owned several sho's over the past 3 years including 89's, 99's, and several in between. In the past 6 months i've bought two 91's (i love the first gens the best). Both of them are white with black interior. One is a non-plus with a fiberglass hood and a rod shifter and the other is a plus without the rod shifter. Both of them are having brake problems and the problems are exactly the same. The brakes are sticking. After a few minutes of driving you can feel the brakes dragging and a noticable power loss. If you put your foot under the brake petal and lift up the brakes release and the cars run great until you have to apply the brakes again. I have spent several hundred dollars trying to fix them with no avail. I have never had this problem with any other SHO or any other car for that matter. My question is this -Is this a common problem with the SHO's or mayby just the first gen SHO's? Does anybody have any ideas what the problem might be and how to fix it? I find it very odd to have the same problem with two different cars. I would love any input you might have.

 

[93rev2sev]

Have you replaced the rear rubber lines? They will eventually get plugged and become a one way valve.

Are the fronts sticking too? If so, I would have a check under the dash to see if there is a brake pedal return spring. It might be built into the master cylinder. I don't know. I'm sure someone does, though.

 

[Mad Celt]

Have you replaced the rear rubber lines? They will eventually get plugged and become a one way valve.

Are the fronts sticking too? If so, I would have a check under the dash to see if there is a brake pedal return spring. It might be built into the master cylinder. I don't know. I'm sure someone does, though.

Another thing that is common with the rear rubber lines is that when they become old, they will actually collapse when hot and cause the brake to stick badly. After they cool, they can usually open back up and work OK for a little while...then they heat up and it repeats.

 

[Irish Pride]

thats funny, my PLUS car seems to run just fine when it has been sitting for a while. then the brakes will start to mess up. i will check the rear lines on it first. i just bought the plus and have not done anything to it yet, but the other 91 i have had since this past summer and have already replaced all of the brake lines. i guess it might be the same problem with two different causes. the only thing is that they both have the same quick fix. if i lift up on the brake pedal in either car the brakes will release and the car will drive fine.

 

[93rev2sev]

Mad Celt is talking about the same thing I am. The steel brackets(they hold the hose to the strut) are the culprit. They rust and expand, pinching off the line. While your pedal pressure is sufficient to clamp the caliper, the pinch in the line restricts the caliper from rebounding. After a minute or 2 of inactivity, the pressure will bleed off, but by then your brake rotor will be in the 300 degree range.

 

[Storm-Chaser]

The rubber hoses can also swell due to deterioration of the rubber material, as well as contamination of the brake fluid.

The rubber hoses can also fail to properly release brake pressure due to clogging of the hose itself.

Additional problems that can cause the rear brakes to fail to release also include the emergency brake cable, and caliper bracket pins.


The fact that SHOhalo can pull-up on the brake pedal and doing so eliminates the problem suggests that the problem is not related to the flexible rubber hoses, but to the master cylinder or ABS.

 

[bassogre]

brake pedal sticks

i was just given a 91 for free from a friend and it has the same problem havn't had it to the shop yet but it is the same thing lift up on the brake pedal and all is good. so is it the rubber lines or the master cylinder? thanks

 

[dward]

I am having the same proble with my 91. I think it has something to do with the actual pedal assembly. I took an air hose and blew all the dirt and debris out and soaked everthing with wd40 and its seems to help for a few days. I havent had time to get any farther into it.

 

[sperold]

Replace the rubber lines and your problem will go away - guaranteed! It has happened on my 90 as well; and yes, it is the steel mounting tab that surrounds the line. It rusts and swells where you can't see it and becomes a one way check valve. I think they all have this mounting clip so that is why we all have the same problem. It would be nice to seal this area, but how would you ever find something that is compatable with the rubber coating on the flex line?