jpsstewart3

Im driving to Cali, starting the Rubicon monday so I need to fix my brakes.

I just replaced my front pads (95 4Runner v6 with ABS) and now I practically have no breaks, they were pretty weak before. I bled all 4 corners using a small tube fed to a cup full of break fluid so no air would get back in. Haynes catalogue also said to break each line coming out of the master cylinder to bleed it which I did but I still have practically no breaks. If I pump the pedal up several times it will build pressure but then slowly go back down to the floor when continuing to press the pedal.

What do I do, replace the master cylinder?? The parts store said theres a difference in master cylinders for ABS and non ABS equipped vehicles (I know mine has ABS b/c the light's been on forever). Does it matter which one I use?
Please help, I just need them working enough to hold myself while on obstacles.... thanks.

dropzone

iTrader: (6)

I would have started this earlier than the day before I leave
I would replace it with the abs cylinder. You might find some trouble shooting help using the fsm link in my sig..

Also if you don't have the brakes fixed and functional don't take your truck on the trail where you run the risk of hurting other wheelers...

jpsstewart3

Well of course I won't take it out w/o brakes. Plus I've been traveling/ just finished engine swap, hence why I'm so late on getting to the brakes. But you think replacing that would suddenly give me brakes? I was told the ABS basically just consists of load sensor valves in the rear drum brakes.

angrybob

+1 on the ABS master cylinder.

If you hold constant pressure and it slowly goes to the floor, one of the seals is bad. Pads swap is probably coincidence and they are likely still green...especially since you said your brakes were bad prior to the new pads install.

I would do this before you hit the road so you can do a bench bleed on the m/c (bench bleed instructions usually come with a new m/c). This will make life easier.

Rear ABS has a single sensor that goes into the axle housing over a ring inside. It's a passive sensor that reads the teeth on that ring. It calculates the speed of the axle by the time it measures from ring tooth to ring tooth. When this ring speed is dramatically less than actual vehicle speed, it dumps pressure to the rear circuit. That's all it can do is dump pressure.