ajoebob

i'm having some brake problems. i broke the bottom off the LSPV. the part where the rod is supost to conenct and my master cylinder is going out. i got the new mc but i dont know what to do about the lspv. heres what i was thinking.
1. drive it that way
2. plug the line that goes from the frount to the lspv. that should give me full psi at the rear becuse the valve will think i lost frount brakes.
3. pull it off plug the frount line and put a proportioning valve on it.

now all 3 will work(i think)and i think #3 is best but will 2 work for now?
this is an offroad only truck and is 4 wheel drive 98% of the time. so the the frount and rear are locked together so the frount and back should slow down at the same speed. am i thinking right?
i have an offroad trip this weekend and dont have a proportioning valve, thats why i'm asking.
thanks

GenXr

If I understand what you've described, the rod has broken off near the LSPV and you can't get it out to R/R, right? IF that is the case and there are no leaks the brake system will act as though you have an empty bed, which should operate just fine for you offroad until you can remove or replace it.

It sounds as though Option #1 will work and let you get by until you find a new valve.

4Crawler

iTrader: (3)

I found on my '85 LSPV that the sensing rod end would raise up by itself, I rigged a mechanism to hold it down a ways so I could adjust the brake biasing. But if yours has raised up all he way, then option #1 would work OK. That is full rear brakes, only thing to watch for is the rear end locking up first.

ajoebob

now that i think more i think your right 4crawler. with the rod broke off the valve would be down which would make it think i had a heavy load becuse the rod pushes the valve up when empty. but 1 thing when i'm in 4 wheel drive the rearend should lock up at the same time as the frount becuse the tranfercase locks them together right?

genxr the rod isnt broke the part the rod hooks to is broke off i see what your saying too. if it still had some of the rod it would push the valve up from the rod hanging down. i'm thinking of it like a sea-saw (bad spelling,i know)the rod goes down it pushes the other side down
thanks for the fast help.

4Crawler

iTrader: (3)

Sensing arm attaches to axle, LSPV valve attaches to frame. When axle moves away from the frame (i.e. no load in the bed) rod moves downward, tells LSPV to cut rear brake pressure. When axle moves towards frame (i.e. lots of load in the bed) sensing rod moves up and tells LSPV to increase rear brake pressure. I noted on my '85 that the sensing rod (when cut off) tended to rise on its own.

And yes, in 4WD the front and rear axles are directly coupled via the transfer case.

ajoebob

ok thanks for your help. it helps me to post and get a few other ideas from others to see if i'm seeing it right. hopefully it will help someone else also. i'll run it as is for this weekend till i get the new valve.

jtruck79

hey guys i pulled my lspv out completely and installed a willwood adjustable valve so that i can dial in my rears. way better than unexpected rear lockup. i dont haul ne thing except maybe a cooler. so that was my fix when i broke mine. HAVE FUN MAKE FRIENDS