ok before all you guys rip me out a new (_*_) hole, i actually used the search function on this forum under "brakes" to diagnose my spongy brake problem. I went through 4 pages of "brakes" thread the last couple of days & still have the same spongy brake problem.

here's what's been replaced so far: F&R pads/shoes, rotors, drums, wheel cylinders - all new - 4 months ago. bled the brakes after replacing & the brakes worked fine.

now just last week - my brakes felt spongy & brake pedal went lower than the usual stopping point (where i had to pump twice to stop). so i replaced the MC yesterday & bled both the MC & all 4 wheels. still have the same issue. i looked under the dash & saw that the rubber boot behind the booster was wet but not showing any leakage when i press on the brake pedal.

is it time for a new brake booster? what do you guys think?

 

Sounds like the seals in the booster are shot to me. Disconnect and plug the vacuum line to the booster and see if they're still spongy. The pedal should be hard as with manual brakes. JMO

 

i forgot to mention that the pedal is firm when the engine is off. but when the engine is on, it's spongy. i will try your suggestion dan. tnx.

 

x2

how did you bleed your system?

 

and now would be your chance to upgrade to a dual diaphragm booster. was the best mod i've done so far. 15 bux from the wrecker with the master still attached.

 

i bled it the old fashion way. one person person stepping on the brake while the other open/closed the bleeder.

 

I just had this problem today, For me it was one of my brake lines screwing into the drum cylinder on the back, it was stripped, so I just pulled it off my parts jeep and was good.

Might not be your problem but I know my brakes were going to the floor and had to use the E-Brake. scary stuff lol.

 

thought i'd fill ya'lls in. i changed my brake booster yesterday. now the brakes feel a little better. although now there's some scraping that i'm hearing on the left rear drum. oye vey!!! i'm about to replace my whole XJ. haha