Brake Fluid leak

[Dbryscho]

First of all I am new to this forum and just bought my first CJ a few days ago. It is a 86' with the AMC 258 i6 / 4.2l . My question is odd to me but maybe someone has experienced this before. I was at a red light when my brake pedal went to the floor and I started to roll backwards. So I pumped up the pressure and everything seemed normal again. I pulled over to check for a leak. The left rear was leaking right at the drum. Now no matter how hard I press the brakes I can not get it to leak again. I drove it home about 15 miles stop and go, and no issues. I left town and have not had a chance to inspect any further but I will next week. Anyone know why I could lose this pressure and have it come back with no issues? Thanks

 

[dalefan88]

i would get a new wheel cylinder and also check the line going into the wheel cylinder.

 

[BusaDave9]

DaleFan88 hit the nail on the head. It is most likely your cylinder and while you're replacing it closely look over you brake line. Just because you can't get it to leak again doesn't mean you don't have to worry anymore. I think when it started to leak you naturally pressed harder and that made it leak more. Don't try pressing hard again unless your jeep is in the garage where you plan on doing your brake repair.

 

[Old Dog]

i would get a new wheel cylinder and also check the line going into the wheel cylinder.

X2, you don't want it to happen again. might not be so lucky next time.

 

[Dbryscho]

Fantastic. Thanks guys. I wasn't sure at first since it only happened once. But I will be taking care of that Monday. I appreciate your feedback.

 

[dalefan88]

your going to need new shoes to if the fluid got on them. if the brakes havent been done in a long time new hardware to. dam i sound like a parts counter guy lol.

 

[jeffgtoman]

First of all I am new to this forum and just bought my first CJ a few days ago. It is a 86' with the AMC 258 i6 / 4.2l . My question is odd to me but maybe someone has experienced this before. I was at a red light when my brake pedal went to the floor and I started to roll backwards. So I pumped up the pressure and everything seemed normal again. I pulled over to check for a leak. The left rear was leaking right at the drum. Now no matter how hard I press the brakes I can not get it to leak again. I drove it home about 15 miles stop and go, and no issues. I left town and have not had a chance to inspect any further but I will next week. Anyone know why I could lose this pressure and have it come back with no issues? Thanks

Are you sure you have brake fluid leaking at the left rear. It could be rear end oil. Mine had a leaking axle seal there and it coated the shoes and backing plate. It even dripped on the rim. What you described happening at the stop light sounds like a bad master cylinder. The rubber piston inside could be hardened. It will bypass fluid on a light brake application and the pedal can go to the floor but if you push harder, it will spread out and seal. Check your fluid level in the master cylinder. If the fluid is not low, you probably need a new master cylinder.

 

[Old Dog]

Jeff may be on to something here. Check to see what is really leaking in the rear.

 

[fzsk4p]

Brake fluid is thin and watery. Will evaporate.

Axle fluid is thick and heavy. Smelly and does not evaporate.

My first though when reading the post was a master cylinder.

Gotta find out if the leak is brake fluid or axle fluid first.