My brake light came on when I engaged the emergency/parking brake and it is on all the time now. I eliminated the parking brake switch by grounding it out. I removed the rear drums. The right side is OK, but the left side was rusted badly. I pumped the brake then engaged the parking brake to see if everything was working properly. One of the pistons in the wheel cylinder came out and the seal looks torn. Brake fluid is leaking on the ground, so I am trapping it and returning it to the master cylinder so it doesn’t run dry.

Can I replace the wheel cylinder with one from another truck? I have another ’96 Blazer I’ve been using for parts. I can’t drive it like this and I don’t have extra wheels to buy a new cylinder.

 

What year is yours?

 

look up the part on autozone.com or something and see if there the same part number.once you get that done make sure the shoes didnt get soaked with bf if they did your going to have to replace them.

 

they are PROBABLY the same but yeah they are probably like 15 bucks at autozone. brake parts are the one part i hate buying used. if that other truck has been sitting a while it might be crap too. also spray down the brake line with some rust penetrating stuff, i just did 2 wheel cylinders today on a dodge and both brake lines broke, even though i sprayed the day before.

 

Thanks guys. I went ahead and swapped wheel cylinders, because I was in a bind and needed to get somewhere today. My Blazer is '96, same as my parts truck. The replacement cylinder was rusty too, but it still held fluid. The best part is, the brake light went off after braking a couple times and the pedal isn't soft anymore. This might explain why I fish-tailed a couple times braking on turns. I only had one rear brake working.

I suspect, abig84, you are right that the other cylinder is not long for this world. I'll replace both cylinders soon.

Serrasalmus, I think the brakes pads, did get soaked. Not sure. Why is this a problem? Is there any way to clean them? There's hardly any wear.

 

brakes on metal make heat and brake fluid does have a flash point within the range of that can be generated by stopping, i was always taught if they get soaked replace them not worth the safety risk but i have no proof just what Ive been taught