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-   -   bad brake booster and hard to press brakes (https://www.yotatech.com/forums/f116/bad-brake-booster-hard-press-brakes-291713/)

cuaco-ortiz 10-29-2015 10:05 AM

bad brake booster and hard to press brakes
 
hi guys, need some help here.

I've got an 87 4Runner i just bought, but the brakes are bad.
i already replaced the master brakes pump, but know the feeling if spongy and the brakes are still hard to press.

i checked the vacuum going to the brake booster, and there is vacuum there, so what else? the idle does not vary when brakes are applied.

i was thinking that maybe i need a new brake booster, my question is, can i swap one from an 90-95 4 runner?

also, do i need to re-bleed the brake lines because of the spongy feel?

thanks guys..

RJR 10-29-2015 11:39 AM

If the rear brakes are badly out of adjustment you can get similar symptoms. The rear brakes are adjusted when the e-brake is applied. If the previous owner never used the e-brake (common if it has an automatic transmission), they could be pretty far out. Pull off a drum and take a look.

cuaco-ortiz 11-02-2015 10:01 AM

the rear brakes are fine, PO installed new brake shoes, and they are properly adjusted.
As for the emergency brake, there is a lot of length to pull the lever out, so I adjusted it, but still the brakes are hard, and now spongy and it fails to stop quickly.

So i am not driving it right now.

the Brake booster when I apply the brakes, kinda changes the RPMs a bit, but not as if it would die on me, is almost unnoticeable.

the question is? can I use one from a newer 4runner? an 89-95 one?

there are plenty of those in the junk yards around where i live, but no older ones like my truck.

so what do you think?

scope103 11-02-2015 10:25 AM

"spongy" is the classic sign of air in the brake system; it needs to be bled.
Here's the manual section: http://web.archive.org/web/201203161.../3checksan.pdf

cuaco-ortiz 11-03-2015 08:01 AM

I'll need to re-bleed the system prior to finding out if the brake booster is bad.

I'll do that this week, like I said, the truck is parked and will not move it until this brake deal is done, safety first...


Thanks...

In case the booster is bad, does anyone confirmed if a newer one will fit on my 87?


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