LJ70 2LT No Brakes ! When powered off air leaks out.

[kylepacemt]

Hi All,

I have a 1990 LJ70 (square headlight) with a 2LT and I've been having an issue with the brakes for a while but now its at a point of no return. So for a while when I'm driving and I press the brake for a couple of times, the parking brake light would come on and the brake pedal would be really hard and I thought this was due to the fact I introduced air into the system since I unplugged a hose to connect the 4wd vacuum system.

Around a week ago I decided to bleed the brakes as I also noticed the brake fluid being black and murky in the master cylinder, I bled all 4 wheels and the system got worse no brakes now, I also eliminated the 4wd vacuum for now and I have a direct connection from my alternator > vacuum pump > Brake booster but still the same and when I power off the engine and press the brake pedal I an hear the air leak from the booster area.

My next steps where going to be :

1. bleed the proportioning valve
2. change the brake booster
3. change the master cylinder
4. bleed the entire system allover.

Any suggestions? Thanks a lot

Kyle

 

[Squash]

Make certain you don't have a stuck caliper.
Otherwise swap out the crappy fluid and bleed as fsm.
How are you bleeding?
Old school or vaccum bleeder?

 

[kylepacemt]

Make certain you don't have a stuck caliper.
Otherwise swap out the crappy fluid and bleed as fsm.
How are you bleeding?
Old school or vaccum bleeder?

Thanks ill check for a stuck caliper.

Oldschool bleeding tried the one person bottle method and also 2 person pumping the brake pedal.

 

[clintnz]

As above check the calipers are all working & do a bleed, if you are new to this maybe find a youtube tutorial so you get a good understanding of what you are doing. Don't use a vacuum bleeder, when I tried that on mine it pulled air into the system. Don't worry about the booster until you get the hydraulic side working.

My LJ71 has a small vacuum accumulator hidden under the booster, if you have that plumb it back in & check for leaks if you haven't already, It has the vacuum sensor that triggers the warning light & IIRC there is also a non-return valve in it so you don't loose vac so quickly with the engine off.

Cheers
Clint

 

[kylepacemt]

Hi, quick update. This was solved. 2 Main issues,

vacuum leak caused by torn pipe between vacuum accumulator > brake booster

brake issues > worn master cylinder.

Got a brand new master for 60$ off ebay as an original Toyota one cos almost 400$ here in Malta, but I got a seal re-kit for the original one so I rekit it and kept it as spare

Sorry for the late reply.

Thanks