FJ62 Brakes - three things that really improved mine (1 Viewer)

[EscapeWagon62]

I’ve been trying to get good braking performance on my truck since I bought it a little over a year ago. I figured I”d share some of this adventure in the hopes that it helps someone out.

Obviously start by adjusting rear drums properly and bleed all four corners plus the LSPV

1. Brake booster pin adjustment. I had to install a brake booster and master and I adjusted the booster pin by using the DAB of grease method shown in another thread. Brake pedal still felt spongy, went and got the proper booster pin tool and found that I still had 4mm of gap when spec is zero gap. IMPROVEMENT = good.
2. LSPV - I know many folks bypass it but I wanted to keep it. I also didn’t know if mine was working properly so I borrowed some brake pressure gauges and performed the LSPV test as shown in the manual. I have to adjust mine at the valve vs on the axle shackles. I WAS SHOCKED at how little movement of the valve was needed to cause 100PSI changes in pressure. I moved the valve in 1/16th inch increments until I could meet the PSI levels shown in the manual. IMPROVEMENT = dramatic
3. Pedal feel. I still had travel (not play)in my brake pedal. I loosened the nut on the pedal and lengthened the rod by turning clockwise util it felt right. This part takes some trial and error. Extend it too far and once your brakes heat up they wil start to drag.after a few miles of driving Too far the other way and your brakes engage too late in your pedal stroke. Took me four tries but I have where it works great now but if they do act up I carry a 14mm wrench and can readjust. Improvement = pedal feel is dramatically bettter.

I almost can’t believe I’m going to say this but the brakes feel close to a modern car now.

Hope this helps someone.

 

[Kleatus]

Nice work. Great to see someone taking the time to adjust things property instead of swapping in a bunch of "better" parts.

 

[Ocho77]

Haven’t seen “Baer” since my racing days! They produce some killer brake systems.

Nice work on the 60!

 

[60Works]

Very good information. Thank you.

 

[Skniper]

Really good info. Thank you.

I made my own booster adjust tool out of some metal strap and three long screws with lock nuts JB Weld'd to the strap. Seemed to worked really well.

Interesting info on the LSPV adjustment. I'll bet most people see that page in the FSM and just skip past when they see SST gauges, etc...I know I do. I'll bet most LSPVs are out of adjustment too, especially if the truck has been lifted. If lifted, the LSPV should be lifted too with ~2" spacer block. Even with the spacer, I think your testing above would prove the LSPV needs a more "scientific" fine adjustment.

I can attest that the LSPV definitely works....before my lift the rear springs were completely flattened out with the rear of the truck squatting down, simulating a heavy load. My rear brakes would lock up very quickly under hard braking as the LSPV was distributing a lot more (too much) pressure to the rear brakes. After lift install and a spacer under the LSPV, braking became much more evenly distributed front/rear. I'd really like to perform the test you detailed above.

Don't quite understand what the pedal adjustment does. I thought that was more about adjusting the pedal arm to engage the brake light switch properly. Need to go stare at mine to understand that.

Great info, thanks.

 

[Skniper]

@EscapeWagon62 just noticed you're in H-town. Maybe my precision adjustment guy is closer than I thought. Lol.

 

[EscapeWagon62]

Really good info. Thank you.

I made my own booster adjust tool out of some metal strap and three long screws with lock nuts JB Weld'd to the strap. Seemed to worked really well.

Interesting info on the LSPV adjustment. I'll bet most people see that page in the FSM and just skip past when they see SST gauges, etc...I know I do. I'll bet most LSPVs are out of adjustment too, especially if the truck has been lifted. If lifted, the LSPV should be lifted too with ~2" spacer block. Even with the spacer, I think your testing above would prove the LSPV needs a more "scientific" fine adjustment.

I can attest that the LSPV definitely works....before my lift the rear springs were completely flattened out with the rear of the truck squatting down, simulating a heavy load. My rear brakes would lock up very quickly under hard braking as the LSPV was distributing a lot more (too much) pressure to the rear brakes. After lift install and a spacer under the LSPV, braking became much more evenly distributed front/rear. I'd really like to perform the test you detailed above.

Don't quite understand what the pedal adjustment does. I thought that was more about adjusting the pedal arm to engage the brake light switch properly. Need to go stare at mine to understand that.

Great info, thanks.

In my case the brake pedal adjustment was used to take up what I will call slack in my booster. It’s an aftermarket Unit and and the rod needs to travel a bit before it engages the vaccumum. May just be an issue with the type of u it I bought. My brake switch was set correctly and the pedal sat at the right height from the metal floor. When I depressed the pedal it traveled 1.5-2 inches before any brake pressure registered on the gauge.

 

[EscapeWagon62]

@EscapeWagon62 just noticed you're in H-town. Maybe my precision adjustment guy is closer than I thought. Lol.

Feel free to PM me if I can help. I borrowed the gauges from the regional Toyota office tech center (I know a guy ther) and will be returning them Monday.

 

[FJACS]

Maybe take a few more photos of the sst. It doesn’t look too complex. Two 160psi gauges adapted to some flex brake hose might work.

 

[EscapeWagon62]

Maybe take a few more photos of the sst. It doesn’t look too complex. Two 160psi gauges adapted to some flex brake hose might work.

Here you go. I think you are correct with the exception of having to get to 1400 PSI for the test and the gauges need to have a brake bleeder
Photos attached