BJ70 brake and LSPV problem (1 Viewer)

[vicious77]

I am facing brake problem in my bj70.
First of all i replaced master brake cylinder from a pzj70.replaced rear wheel cylinders.brakes improved a lot.but rear wheels were not working at all.so i replaced LSPV.after replacing LSPV rear wheel brakes become more agressive and bj70 started rear wheel skiding.the rear of my bj70 turned completely with brakes.
Then i removed LSPV and installed a T but same skidding problem and rear of bj70 turned with brakes.
Then i installed another LSPV from 4runner or toyota pickup but installed the orignal rod.as the rod on 4runner LSPV was short.
my bj70 is 2.5 to 3 inch lifted
i am attaching pictures of LSPV kindly help me how to adjust it properly.i think there is adjust nut on LSPV can it be adjusted from there?or i have to make a bracket?
Please guide me how to adjust it properly

 

[ozcrusier]

When you load your truck the body/tray will compress the suspension making the rod move up applying more braking force to the rear brakes.
If your leaf springs are sagged this may also cause your problems with the brakes locking up but back to your questing you need to adjust the rod closer to the drive axle and or raise the LSPV valve.

 

[Malahki]

My advise it to get rid of the LSPV all together by changing the 3 way tee at the front to an elbow and eliminate the 2nd brake line. Join your hard line to your soft line at the back with another fitting mounted to the frame and your done.
If your still not happy add a manual brake proportion valve to adjust it to your liking: Wilwood High-Performance Disc Brakes - Porportioning Valves & Pressure Valves

 

[jblueridge]

I was not sure what to do with mine in my 2 inch lifted BJ74. On the axle near the differential, I disconnected the LSPV Rod, then used the threaded part to spin the bracket around and around to make it go up higher from the axle. This is the opposite from what Oz wrote, but I was thinking about my truck's lift.
You wrote that your truck was lifted also.

Before I tried to adjust anything, I disconnected the rod, then used some wire to hold that end all the way up to the body. I drove a short way and tried the brakes. Next I used the wire to tie the end of the rod very low on the axle... I drove some more as a test. I was then sure that the LSPV and rod were working.

Raising the rod higher seemed to be the right thing for me.

 

[ozcrusier]

I missed the part about the lift but with lift you normally lose brakes so you need to extend the bolt on the diff housing raising the rod. The OP has the problem that his rear brakes are locking up to early so my thinking is he needs to lower the rod maybe I have got it arse about.
I will pull a manual and have a read.

 

[Malahki]

Yeah when I first lifted mine with the 2.5" OME and extended shackles I added this 3" spacer to the LSPV to compensate for the lift and still give me adjustability.

 

[ozcrusier]

https://www.superiorengineering.com.au/image/data/pdf files/big-lift-brake-bias.pdf

 

[dabasscow]

Dobinsons have a brake adjuster as well

 

[vicious77]

Thanks for your help.
but my problem solved strangely.
i fully loaded my bj70 as i was on a week trip.brake became awsome.after i came back unloaded it and brakes are perfect now

 

[ozcrusier]

That's good news but strange as it may have been gummed with crap and the good work out got it freed up again might be a good time to swap brake fluids.

 

[jblueridge]

I hate it when something fixes itself for no reason.
Oz is right about flushing/changing out the fluid.