Can't/won't stop. Mushy/stiff brakes.

[FauxRunner]

I've poured over this and other sites trying to find a discussion or solution to my problem. While others have described similar problems they're not quite what I'm experiencing.
I have a 99 T4R limited.
When driving, the brake pedal 'hisses' and stiffens up as I apply pressure. The 4R barely (and I mean BARELY) slows down until I mash with great force down on the pedal. If I put the T4R in neutral it's easier to stop but not easy. There is less pressure from the pedal.
When in park there is the same hiss as when in drive.
It has 203,000 miles on the odo.
It has the infamous rear axle shaft seal leak.
Needs shocks and struts all around. Maybe Tundra.
My goal is to do the 231mm tundra brakes mod. It obviously needs brake work.
The dealer said its time for front and rear diff service, tranny flush time, coolant flush and transfer case service.
I wanna have fun with this rig, but $$$ is tight.
My priority is the brakes since they are saying it could be the MC or the Booster and they won't know until they start cracking it. Help please.

 

[shootmymime]

sounds like a stuck valve or a bad booster since you have no power brakes.

 

[LittleCaesar]

I would say that shootmymime is correct in believing it is a bad booster.

Turn off the 4runner on a level surface. Pump up the brakes three or four times rather gently. The next time pump the pedal with all your mite. If you have a vacuum leak (most likely in the booster), the pedal will travel down some distance.

Car-Part.com--Used Auto Parts Market for a cheap used one near you at a local yard.

 

[shootmymime]

When driving, the brake pedal 'hisses' and stiffens up as I apply pressure. The 4R barely (and I mean BARELY) slows down until I mash with great force down on the pedal. If I put the T4R in neutral it's easier to stop but not easy. There is less pressure from the pedal.

Turn off the 4runner on a level surface. Pump up the brakes three or four times rather gently. The next time pump the pedal with all your mite. If you have a vacuum leak (most likely in the booster), the pedal will travel down some distance.

thats a great way to test the booster, never heard of a way to do a quick test but ill have to add this to my tricks.


i think the hiss you are hearing it your booster leaking.

 

[FauxRunner]

Heh. Thanks for the replies. I need all the advice I can get.
Tried the level ground pump then mash with all my might suggestion, and maybe I'm just not sure what it feels like. Should it be effortless when I mash with all my might? The pedal offers quite a bit of resistance when T4R is running, and a little less when not. Thanks again.

 

[Skidmarcx]

Agree on the bad booster

 

[FauxRunner]

Hey, thanks again for the responses. I'll take the advice to the bank.

 

[FauxRunner]

Fixed

Installed the new brake booster. Immediate improvement! Also did the Tundra 231mm upgrade, bled the brakes and bedded the brakes. Night and day. Thanks again!