Help! Odd brake issue...

[thetimmy]

I have an 02 wrangler x and I am losing brake fluid... Most of the time I have a good solid pedal but every once in a while my brakes are just gone and the master cylinder is almost empty. I cannot find any leaks or signs of leaks, and after I refill the master and pump the pedal a few times I get my brakes back... I even pulled the vacuum line from the booster to see if fluid was leaking back into the booster and being pulled into the vacuum line but it is clean and dry.. Has anyone seen this issue before or maybe have any idea what is going on with my brakes?

 

[greg92jeepxj]

Hello and welcome to JEEPZ.com . That was a good check for the master cylinder to see if the master leaks from the rear which would also cause fluid to seep past the mounting to the booster. Ok , so you cannot find any leaks from any steel lines or hydraulic hoses or even the caliper Pistons either . The only other place I can suggest to look is the rear brake cylinders . You'll have to pull the wheels off and the drums and check for any signs of moisture and paint fatigue of the backing plate which may indicate the brake fluid has corroded at the paint. Try peeling back a rubber seal to see if brake fluid is present which will tell you've got a leak. If these are the original wheel cylinders , they're probably in need of replacement but check them since your trying to verify where the leak is. Take a good look at the caliper piston seals to. Anywhere that is wet from brake fluid is not normal of course since the brake system is a closed system and can certainly be considered a leak. Before pulling off the rear drums , pump the brake pedal several times and check . Let us know what you find. Hope this helps . Thanks for your membership here at JEEPZ.com .

 

[JPNinPA]

I have an 02 wrangler x and I am losing brake fluid... Most of the time I have a good solid pedal but every once in a while my brakes are just gone and the master cylinder is almost empty. I cannot find any leaks or signs of leaks, and after I refill the master and pump the pedal a few times I get my brakes back... I even pulled the vacuum line from the booster to see if fluid was leaking back into the booster and being pulled into the vacuum line but it is clean and dry.. Has anyone seen this issue before or maybe have any idea what is going on with my brakes?

Based on your exact description I have to ask...Did you bleed the brakes after filling the master cylinder? Was the Master cylinder dry, or just a bit low and you could see lots of fluid?