TheCoffee

Last week I replaced the ball joints, shocks, rotors, and brakes on my 95 4Runner, bled the brakes and they worked fine until the other day the brake pedal would get very hard and would not fully apply braking. This was intermittant for a couple days but now is nearly constant and only occasionally does the brake pedal and braking act normal (ish). Do I still have air in the system or am I losing my vacume assist?


EDIT: Also noticed when cold if I apply the brakes it alters the idle, makes it drop and get rough making me lean towards a vacume problem


thank you!

akwheeler

you either have a big vacuum leak or your brake booster is failing.
Since you mentioned that hitting the brakes makes it run rough I would say it is your booster.

old87yota

x2 what akwheeler said. It does sound like your vacuum assist (brake booster) is not working properly and likely causing a vacuum leak.

Check your brake booster vacuum hose for cracks. Any cracks can cause a vacuum leak and loss of booster performance and is easy to check.

You can try the brake booster operational test in the Factory Repair Manual and see if the booster passes or fails the test: http://htftp.offroadsz.com/marinhake.../3checksan.pdf

TheCoffee

Ordered a reman booster, thanks guys

wallytoo

iTrader: (1)

did you test the one in your truck first?