Brake Booster Diagnosis (1 Viewer)

[NMC_EXP]

50 years ago I did a lot of my own maintencence based on what my Dad taught me. Then the job and family caught up and I outsourced most of my vehicle maintencence. Now at age 71 I cannot remember much of what Dad taught me. And that is a damned shame.

I have a 1985 FJ60 with all the bolt on stuff: ARB bull bar, winch, 7 ft Wilderness roof rack, rear spare swing out plus ladder bumper and a 4" lift. Has the original engine and trans and runs well.

I got busted up 2 years ago and had not driven it much. Now when I drive it it seems the brakes suck. The pedal is hard and it flat does not want to stop.

My fuzzy troubleshooting memory of a hard brake pedal is the vacuum booster is bad.

Already checked, the booster is NLA from Toyota.

I'd appreciate any and all advice on how to troubleshoot and correct this problem.

And yes, I did a search so stuff that smart ass response.

Regards

Jim

 

[klinetime574]

With the engine off does the pedal get firm and gain height when pumped? Or is it just hard?

I’d also be worried about corrosion in the hydraulics after sitting that long. A brake bleed would confirm fluid movement if you wanted to check that.

Glad to have you back. Let’s get that 60 running!

 

[OSS]

Usually a brake booster doesn’t die just sitting unused for years on end. I bet there’s nothing wrong with the booster.
In my experience, the front disc rotors can rust up (they’re unprotected steel) or develop a film of some sort of corrosion on them when unused for years especially if the vehicle is stored outside.

You could try removing the front brake rotors and have them turned (lathed) at a shop and replace the brake pads too.

Could do the same with the drums in the rear too.
New brakes, once they’ve bedded in can stop the vehicle safely.

I know when my cruiser was fully loaded, it’s stopping distance increased a lot compared to when it was empty. Also getting rid of the 125lbs winch really improved braking.

 

[toy_tek]

Hang on... troubleshooting 101... easy/cheap stuff first... confirm vacuum at the booster: Engine running, remove the vacuum hose and plug it with your finger. Inspect the hose for cracks.

 

[Gretsch]

Inspect the hose for cracks.

Recently ran into this with mine. Found a split in my hose right where it was covered up by the clamp off the vacuum supply. Symptoms were no stopping when applying pedal. Not really a hard pedal but truck just wouldn't stop. Replaced hose and its been good since. HTH.

 

[cheeese]

Definitely perform a fluid replacement and bleed if it's been 2 years. I would also pull the calipers, inspect the seals and see if you can easily retract the pistons into their bores. It's possible that some corrosion in the bores has seized the pistons in the bores and they're not extending all the way.

 

[BamaHeel]

Does anyone have the PN handy for a 60?

Mine is a late 85 if that makes a difference at all.

 

[Godwin]

Does anyone have the PN handy for a 60?

Mine is a late 85 if that makes a difference at all.

4461060440​

 

[2mbb]

For the OP, here are the trouble shooting and Checking procedures for Brakes from the FSM.