Hello All,

Recently I noticed my brakes feel a bit spongy. I can hear a hissing sound as I apply pressure to my brake pedal. This morning I noticed a puddle of fluid under the drivers side firewall. Could this mean Master Cylinder needs replacing? I can't tell where it may be leaking from. I also noticed the rubber seal under the master cylinder cap wasn't fastened properly. I'm gonna see if this fixes my problem. haha!

 

hijacking this thread so I get updates about it. I have something similar on my 2000. Hit my brakes and it almost sounds like a puff of air from near the pedal. No brake fluid leaks, everything is perfectly full, nothing seems wrong other than having to brake a little sooner. Hopefully someone has something !

 

you sound like you need to bleed the master cylinder

 

fix the cap as that is a pressurized system, then see from there what you've got for leaks .. Brake clean everything and have a buddy sit in it and pump the brakes while you look for leaks. It's probably a line fitting leaking.

 

This is actually on the list for this weekend! Just bought a bleeder kit so I'm having the girlfriend helping me out. good to know I'm on the right track with it

 

I'm betting the leaking master cylinder has taken it's toll on the innards of the booster.

Both are probably in need of replacement.

 

My 1992 MC was leaking and it ate the booster guts and the paint on the firewall.

I pulled a 2002 GC booster and MC and did the conversion.

Its like night and day. My XJ now has nice firm brakes that will stop on a dime and give you change back.

I suggest finding a local salvage yard and doing the booster/MC upgrade. You will also need the MC brake lines that run to the prop-valve. They will need to be bent to line up.

WELL worth it. I think I spent under $50 for the entire project. Look into it.

 

You are correct.

 

It was the MC Rubber Seal. I seated it properly and cleaned up the surrounding areas with brake cleaner. DUH!!! No More Leaks!!

 

awesome glad to hear it!

 

That rubber seal in the master cylinder cap is actually a seal and a water separator. It's a good idea to remove the rubber and clean it off a few times a year, especially in high humidity areas.

 

Noticed spot at my front passenger tire today while clearing snow. It snowed all day so the leak is current, if that's what it is. First thought was a dog relieved itself on my tire but there were no tracks at all. Picture for context. I'm thinking break line or master cylinder but I am not a gear head.

 

Not master cyl, more like wheel caliper in that location, get under and have a look with a good light

looks like you have a later model ?

XJs finished production in 2001