Brake booster gone bad, what to replace it with

[arcteryx]

Truck- 86 4runner SR5, 31s and the rest is stock for now.

I am almost positive my booster has gone bad. I have a hard pedal when driving and in a fast break situation, I can lock them too easily.

My question is, will any booster from 86-89 work? Or is this an opportunity to upgrade my booster? Are there any recommended dual diaphragm boosters available? If so, can I upgrade the booster alone or will I need to do the calipers/pads too?

TIA

 

[KLF]

Definitely upgrade, it's worth it (at least it was for me). V6 trucks, esp. 90+ are good, T100 I think it even a little bigger. Do the front calipers too.

 

[arcteryx]

Would a FZJ80 booster work? I have 3 of them.

 

[Combat Chuck]

I don't know if the FZJ booster will work.

I second the T100 booser idea, that's gonna be dual diaphragm.

 

[unorthodox]

Why not a hydroboost booster from a diesel truck or Astrovan? It would be smaller, and the accumulator would give you a few extra power brakes if the engine cuts out or something, you would just need the extra hydraulic line from the booster to the steering box then...

I have seen it done on mini-trucks over @ toyotaminis.com and on bigger trucks on Pirate, but for whatever reason not on offroad pickups like this, is there a reason?

 

[Mr DJ]

If you go the 80 booster, the master will be too small.
Maybe 15/16 master will work better with it.

 

[Combat Chuck]

Why not a hydroboost booster from a diesel truck or Astrovan? It would be smaller, and the accumulator would give you a few extra power brakes if the engine cuts out or something, you would just need the extra hydraulic line from the booster to the steering box then...

I have seen it done on mini-trucks over @ toyotaminis.com and on bigger trucks on Pirate, but for whatever reason not on offroad pickups like this, is there a reason?

That sounds like way too much work for a repair that could easily be done in a driveway.

I'm all for reinventing the wheel sometimes, but things like boosters rarely change because they don't often need to.

 

[ridgerunner]

Why not a hydroboost booster from a diesel truck or Astrovan? It would be smaller, and the accumulator would give you a few extra power brakes if the engine cuts out or something, you would just need the extra hydraulic line from the booster to the steering box then...

I have seen it done on mini-trucks over @ toyotaminis.com and on bigger trucks on Pirate, but for whatever reason not on offroad pickups like this, is there a reason?

I installed a hydroboost unit on my former diesel 55, and while the stopping power was great, you could probably swap the V6 stuff instead and be done with it, for less money. Bolt in stuff vs. modifying brake lines, making custom hydraulic lines, and potentially needing to "upgrade" to a larger saginaw pump. The accumulator is only good for a extra pump or so and then your brakes become even stiffer than the vacuum booster.

There is nothing wrong with the Toyota setup- I did the hydroboost simply because my engine didn't draw any vacuum.

 

[quasi]

You may want to replace the vacuum check valve in the supply line to the booster. This can cause a hard pedal/no boost.

 

[benrold]

T100 booster is a good upgrade, i had one in my old rig. It worked GREAT.

 

[arcteryx]

I have a used stocker en route. I will give it a try.

As far as the T100, what benefits do you get with that? I take it you can run larger calipers. Do you use the T100 MC too?

 

[Combat Chuck]

You can run a larger master if you want- Toyota MC's are 4-bolt all around, and you can run V6 calipers if you want - if your master can manage the output.

The biigest advantages of the T100 booster are: easier pedal. Dual diaphragm means more power to the master with less leverage on the pedal. Smaller. T100 booster's are about 2/3 the depth of the stock 22R/22RE booster, but it is an inchor or two wider, which may cause other fitment issues.

 

[oestr77]

booster, calipers and M/C upgrade

I have an 85 4 runner 4cil manual trans. can I upgrade to a 95 4 runner 6cil booster, master cilinder and front calipers which I already have?
will this hinder with a future hi-steer.
33" tires future 35"

 

[KLF]

I have an 85 4 runner 4cil manual trans. can I upgrade to a 95 4 runner 6cil booster, master cilinder and front calipers which I already have?
will this hinder with a future hi-steer.
33" tires future 35"

No it won't hinder the hi-steer upgrade, but your wheels might rub on the calipers. You will also need to trim the "dust shields" a little behind the rotors.