Rear brakes not working

I recently bought this 1996 4runner 3.4 sr5 and the rear brakes were hardly working. I've changed the rear drums and shoes and they work a little better but still the fronts are about 90-95% of the braking power. i thought it could be air in the system so I took it into the shop and had whole system flushed and rebled. Now they're working a little better but not even close to what they should be. Anyone have any advice? I'm thinking possibility the master cylinder? Any advice would be much appreciated

 

Proportioning valve?

 

Yeah I was thinking about that.... I think I'm gonna try adjusting the rear brakes again tomorrow by using the little clicker on the drum (hard to explain). If this doesn't work I'm gonna look into the PV.

 

Definitely try the adjuster first. Use the parking brake in reverse to adjust. Wait till it grabs then turn it back from there.

 

Check adjustment, proportioning valve, wheel cylinders, make sure axle seals aren't leaking and coating the shoes in gear oil.

 

When you've changed the shoes.... what did they look like??

If the shoes are worn thinner on one end than the other - than the adjuster isn't working properly and/or seized up. The adjuster mechanism should be cleaned up, lubed up, and/or replaced.

Is it obvious that the braking is weaker on one side or the other? You could also have a bad cylinder. A truck that old...I'd change both cylinders.

Check for leaks in the lines going to the rear. If you have a hairline leak, will affect the rear but won't necessarily affect the front braking.
Here's something I've done.... With truck in Park and running, press your foot on the brakes as hard as you can. Hold it there.... for a good minute or longer. If the peddle feels like its 'moving downward' as you're holding your foot on it....there's probably a leak.
The pedal should not move when you're holding it down hard.

 

i changed the rear drums and shoes because the passenger side rear axle was leaking and coated the entire drum with oil. when i replaced with drums and shoes i made sure everything was working properly and none of the mechanical parts showed and excessive signs of wear. My pedal is down to the floor basically when i brake....

 

How about pumping the brakes with the truck off? Pedal should become firm and not move...

 

yeah, when the truck is off and i pump the brakes they get super stiff and i cant press them down anymore

 

We know it's not leaking. You cleaned up the mess made by the leaking gasket so your shoes and the drum should have good contact. And I assume you've made sure the automatic adjusters are in clean working condition and are adjusted properly. Next you need to check the cylinders, it's not uncommon for them to seize up.

Also, check the load compensating valve. I lifted my old Taco and had a hell of a time getting this adjusted properly. Read about it here:
http://www.brakeandfrontend.com/Article/72111/tech_feature_brake_job_on_19952004_toyota_tacoma.aspx

 

So, you're saying that you had the rear axle seal replaced? Did you do this work yourself?

Are you absolutely certain that all your brake line connections are tight and not leaking? Are you absolutely certain the cylinders are working properly and not leaking?

Did you press on the brakes like I mentioned earlier? Truck in park & running. Press on brakes AS HARD AS YOU CAN and as far down as you can and HOLD for 30 seconds atleast. That pedal should not move at all once its reached it lower limit. If the pedal moves down at all while you're pressing hard on it - you most likely have a leak.

 

It's a 4Runner. I'm not certain he has a Proportioning valve in the rear like the 1st gen tacomas do.

 

They had it in 97, willing to bet money they had it in 96. They are also referred to as "Load Sensing Proportioning and Bypass Valves."

FYI- The drivetrains, suspensions, and brakes between the two models were eerily similar through those years. I ran 4 Runner springs on my 95.5 Taco, for example.

http://www.autozone.com/autozone/re...-LSP-and-Bypass-Valve-BV/_/P-0900c152802620fa

 

From what I've read....if its a LIMITED and/or has ABS - it won't have the Load proportioning valve. I've read that some 96's didn't have it.

http://www.top4runners.com/runhist/runhist31996.html
ABS is standard on V6's

 

Maybe the OP will crawl under there and check it out?

 

Abs has been disabled. I'm about to go adjust the rear brakes now. Will keep you guys updated

 

Alright so just got done adjusting the brakes and now they were perfect. My parking brake works again and all is good! Thank you guys for your input!