92 4Runner brake/vacuum issue?

GrizzlyNC · 09-27-09, 08:47 PM

Ok... I have a 92 4Runner SR5 V6, Auto trans, with aprox. 214K on the body and 160k+ on the engine. I recently purchased this rig so I am not all that familiar with the 3.0 vs the 22RE that was in my 91 P/U.

I have searched to see if anyone has had this same issue and could not find anything that matched.

When the brakes are applied (feel a bit spongy) and the vehicle comes to a stop the brake pedal actually rises back up into the cab and pushing my leg up as well. It seems to do this when it is within the last 5 to 10ft of stopping and it doesn't do it all the time. In some cases it will do it while stopped when I just push the brake pedal a little harder a couple of times. Since I have experienced this happening while stopped I am inclined to think that this issue is vacuum based. The MC and the booster have both been replaced, the lines bled, pads are not that old, and the rear brakes look to not be that old. It also looks like a valve block in the rear of the truck has been replaced as well (has rear anti-lock but no anti-lock motor under the hood?). I'm thinking this issue has had others trying to track it down as well.

I have checked the vacuum lines to the booster for cracks, etc.. but do not see any issues. Do any of you have any suggestions as to what I should look at next?

I'm sorry if this is a "noob" question but the brakes just don't seem up to par and I would like to make sure I get the best performance out of them.

Thanks in advance...

Grizz

GrizzlyNC · 09-28-09, 11:32 AM

Any ideas at all?

WristPin · 09-28-09, 01:52 PM

make sure rear shoes are adjusted.
pull out the hose look for oil or brake fluid

GrizzlyNC · 09-28-09, 05:49 PM

Quote:

Originally Posted by WristPin

make sure rear shoes are adjusted.
pull out the hose look for oil or brake fluid

Just had rear drums turned and the shoes were adjusted after re-installation. It did not change anything. :(

I will look at the hose and see if I find any fluids. Thanks..

hardontoyotas · 09-29-09, 05:33 PM

can you hear a hissing noise near the brake pedal when this is happening?

GrizzlyNC · 09-29-09, 05:58 PM

Quote:

Originally Posted by hardontoyotas

can you hear a hissing noise near the brake pedal when this is happening?

No.. It's completely quiet when it happens..

hardontoyotas · 09-29-09, 06:32 PM

you might check to see if you have any collasped rubber brake lines. it might be hard to tell if they ar

aprice2pay · 10-02-09, 05:27 AM

Grizz, from the sound of it, it maybe you just got a bad booster. I replaced the booster on mine twice before I got it working properly. Also sometimes the vaccuum hose on the side of the booster gets pinched during installation.

black95 · 10-04-09, 08:47 AM

Your anti-lock system is driven by the power steering pump, that huge mess on the passenger front framerail, inside the engine bay, is the anti-lock system.

Kinda sounds like you are having trouble with it, but I would be suprised, they just don't really go bad.

Is the brake warning light lit on the gauge cluster? If so get the system checked at toyota dealer.

There is a sensor on the top of the rear axle third member also that "counts" the ring gear teeth to make sure the rear is not locked up. Make sure that the wire going to it is in good shape and that it is still plugged in.

It just sounds to me like something is triggering the Anti-lock system.

Also, there is a check valve on the vaccum line going to the booster, it's bolted to the firewall--maybe check to see if it's working? long shot, but hey, it's worth checking.