LSPV Adjustment with Pictures (2 Viewers)

[coax]

IIRC there are some directions in the fsm that use a brake pressure gauge on each caliper to determine the proper ratio between front and back, though all based on stock spring rate. I imagine that is how it would have to be done to get an accurate reading. Though I think a number of folks just go on dirt/snow, disable the abs, get a bit of speed, mash the brakes, and have someone tell them which wheels lock up first.

 

[7schulz]

I couldn't budge mine so I adjusted the other end of the bar, on the axle side. Much easier to move if your LSPV is rusted.

 

[darwink1]

Hows this for a rotten LSPV and twisted mounting bracket? lol. The valve/bracket/mounting bolts were one solid piece even after soaking for a month straight.

Thank god I had an extra bracket and a new valve on stand by. To my surprise the rearmost bracket bolts came off no problem but the 2 behind the gas tank would not budge. Instead of messing around I just cut the old bracket then cut the new one so they overlapped, drilled a hole and bolted the 2 pcs together.

New

I didnt have a reference point for height since my old bracket was mangled so I just guessed when setting the new one up. It did make a noticeable improvement when braking, the rear brakes seem to grab more than before when it felt like the fronts were doing most of the work.

Also, since the studs that hold the valve to the bracket were part of the old bracket/valve now I had to use bolts/nuts to hold the new one on. I had the bolts in my stash and they worked fine.

D

 

[kidglove13]

I have been messing with mine quite a bit lately.
I redid my rear drums and it was def. grabbing way more in the rear than the front.
I have been moving the axle side down in small incraments.
I have about 3.5" of lift the axle bracket was maxed out.
Now it is to much so I started going the other direction.
My rear drums are adjusted correctly.
After driving how hot should my rear drums be?

 

[warpdriv]

Ok. Read a lot of posts. Looks like its .25" per 2.5" lift, so .1" adjustment per 1" lift. So for a 6" lift that would be .6" of adjustment for a starting point? Then test and adjust?

 

[bog925]

I couldn't budge mine so I adjusted the other end of the bar, on the axle side. Much easier to move if your LSPV is rusted.

I agree I did the same with mine. I made a bracket out of aluminum stock, drilled 4 holes and done

 

[warpdriv]

I agree I did the same with mine. I made a bracket out of aluminum stock, drilled 4 holes and done

So you mounted the bar down the same number of lift?

 

[SiRaDuDe]

I got this... MAF 4+Plus 80 Series Suspension Drop Bracket

80 Series Rear Proportioning Arm Bracket
This Bracket will extend the lever for the rear brake proportioning valve 4" to realign the arm for proper function. Sold each. For about $9


Pending Installation (lazy)

 

[jonheld]

Folks,

Moving the connecting rod higher on the diff housing will cause the connecting rod to contact the left upper control arm and bend the rod. This has been discussed many times before.

 

[SiRaDuDe]

Folks,

Moving the connecting rod higher on the diff housing will cause the connecting rod to contact the left upper control arm and bend the rod. This has been discussed many times before.

First I've heard of this...

Could you please point me to a few threads, I would like to know details.

 

[landtoy80]

Folks,

Moving the connecting rod higher on the diff housing will cause the connecting rod to contact the left upper control arm and bend the rod. This has been discussed many times before.

Even .25"?

 

[jonheld]

You'll have to search. Moving the diff end higher was the original way to adjust for lifts when the lifts first came on the market. However if you wheel your junk, the rod will bend rendering your rear brakes with less bias than before. Ask me how know.
You can do a custom bend to get around the control arm, but that never really worked for me. I wound up strapping the Rod to the control arm. I can adjust the bias by tightening the clamp and it still moves with the the rear axle.
Works well.

 

[warpdriv]

You'll have to search. Moving the diff end higher was the original way to adjust for lifts when the lifts first came on the market. However if you wheel your junk, the rod will bend rendering your rear brakes with less bias than before. Ask me how know.
You can do a custom bend to get around the control arm, but that never really worked for me. I wound up strapping the Rod to the control arm. I can adjust the bias by tightening the clamp and it still moves with the the rear axle.
Works well.

Hi Jon, can you please shoot us a pic of how you did this? Tks

 

[Wheelingnoob]

I had no idea the valve was removable mine is a big ball of rust, I fear taking the lines off will break them even.

 

[jonheld]

Hi Jon, can you please shoot us a pic of how you did this? Tks

It's extremely complex and precise and required months of R&D.

I used a hose clamp and strapped the LSPV connecting rod to the left upper control arm. I tightened this hose clamp until I felt that the rear brakes were working the way I wanted.

On road with street tires it stops great. I have yet to test it off road, but my assumption is that the rod will make contact with the control arm and bend again. The hose clamp will re-adjust the bias. I totally made that last part up.

 

[crooozer]

Hi all,

I replaced my LSPV about a year ago, didn't know how to adjust it so of-course didn't know to mark it before removal. Anyway, I just put the new one on and bled the system, no difference to braking performance.

I just adjusted it this afternoon as far as I could pull it down toward the ground in the hope the vehicle will have better braking performance (the 80 brakes are crap standard) Is this ok? Or, how do I set the height of the LSPV from scratch?

 

[medtro]

.... Or, how do I set the height of the LSPV from scratch?

You could use a brake pressure gauge. See write up at https://forum.ih8mud.com/az-copper-...ing-brake-lines-adj-lspv-bleeding-brakes.html

 

[busmup808]

I run 863Js and did the same thing as ed97fzj80. It worked like a charm. When I 1st lifted my truck, I put the extension on the axle side arm. Then I read about this article and went in the garage to change it. Good write up!

 

[crooozer]

Yes!! Made it to work ALIVE. I was thinking that maybe I'd broken a brake line or soething overnight while I was pulling down on the LSPV or that the pressure of it constantly sitting hard on the valve would cause a fluid leak.

So yeah, still alive! And possibly a braking difference but If so It's really no big improvement.

 

[Brentbba]

Just did this after having my OME heavy 2-3" lift plus airbags for a few years now. I'm only a and it was easy for me. Gotta love SoCal, no rust trucks too! Nice difference.

Thanks for a great write up and pictures.