Heres kind of a tricky issue. About two months ago I was driving the jeep, lost almost all of my brake pedal, and it would only stop if I put it all the way to the floor. No fluid loss at all,no leaks in the system. I bled the brakes, had a nice hard pedal again, and drove it 2500 miles since.

Then this weekend I was about 20 miles into my 50 mile trip and again my pedal went to the floor and had to put it to the floor to slow the jeep down. Pulled it over thinking I popped a line. No leaks what soever. Go to check the master and I pull the cap off and it is to the absolute top and overflowed when I pulled the cap off. Drove it the other 30 miles then 50 miles back home, rebled the brakes and all has been fine since. When I had started out this time the master was at the full level, not to the top.

I've done research, I can't figure anything out. When I rebled the brakes the rears had a lot of air in them, while the fronts had none. When I bled them the previous time there was no air in the lines and I had a nice pedal.

New brake parts as of the past 7 months - Pads - Pass Caliper - Driver rear brake cylinder - Front soft lines - Rear soft line - Both rear hard lines - Hard line from master to rear.

Anyone have any ideas on what it is? My brakes are fine currently I just want to prevent this from happening again.

 

Gotta a leak somewhere or a bad master cylinder

 

Reason I don't think it's a leak because two months of daily driving I lost no fluid and my pedal and stopping ability never changed. It could be the master though I'm just confused in the whole thing

 

A bad master cylinder will leak internally which is why one side is overfilled and the other dry.

 

Nobody has asked if you have ABS.

 

Many of us do not have ABS, so it doesn't cross our minds. It is a valid question.

 

I generally don't think of it either.

 

No abs. I don't buy xjs with it lol. I'm assuming air got into the master and made the rear brakes go out completely which made the loss of pedal but still stopping fine. When I say over flowing through I mean the master was overflowing out of the cap when I removed it. Not just the one side. I think I'm just going to replace the master here soon

 

When a master leaks internally, it goes from back to front pulling fluid from that tank and putting it in the other half. The seal is bad inside. I had a new one do that too.

 

I understand now. Thanks! Looks like I'll be changing it out this weekend...

I have one more issue if you have any idea.
When driving and I come to a stop, sometimes the Jeep smells like propane. There are no gas leaks visible, no smell under the hood, or by gas cap or gas tank area. Can't figure it out for the life of me. Mainly smells that way inside.

 

Is the exhaust getting hotter than usual and melting the undercoating?

 

I don't really have much undercoating under there. I ground it off about a month ago when I sent it to hdoffroad to get frame stiffeners sliders and a hybrid cage.

Now that you mentioned that I'm going to take a look anyway when I get a chance. When I sealed the floor around the cage I used seam sealer and kind of gobbed it so no water comes through the holes and some of it might have fallen onto the cat or muffler somehow.. It's not near it but you never know I guess. Problems been consistent about a week and a half now