Is my LSPV broken?

ChildrenOfBodom

ChildrenOfBodom

Moderator
Hey guys, today I finished installing my OME 883/890 lift and shocks.

Well, in all honesty, I was thoroughly disappointed in the still resulting brake dive, even with firm springs and Bilstein 5100 shocks up front. It is better than before, but still nosedives pretty bad. My occupants always think I'm slamming the brakes, but I am really just slowing normally. At stoplights, I can make the car rock back and forth while just pulsating the brake lightly, and the whole thing moves like hell.

So I thought to inspect my LSPV for possible fault. The drums I have (while I admit, aren't in the best condition) work fine, they're newly adjusted and the E-Brake is very firm.

My LSPV is very confusing. I have heard that when the vehicle is loaded, it causes the LSPV rod to move up, which sounds correct. Mine is already in the "up" position. It can't go any higher. I even took a ziptie to pull it all the way down and try a quick drive, and nothing was different. What can I even do? I took the spring off to see if it would change anything, the LSPV defaults to "up" and is very easily flopped around before returning to "up."

Meanwhile, all the way up, or all the way down, I sense no difference in hard braking or city driving.

I thought that maybe the extra braking power of the Tundra 231's I've got up front may be to blame, but I figured it must be something else when I can't find the LSPV to do anything.

So far, all I've found is that ABS 3rd gen 4Runners do not have these valves.

I just did new Toyota shoes in the back and I have warped Centric brand brake drums. I figure I should replace them too, when I have money. If that's the problem, then sorry for wasting your time, I'm just going nuts here!
 
Register to hide this ad
how much lift do you have? i know on my old 85 pickup i had to bend the rod, cause it would lock the rear brakes way to prematurely and send my a$$ end out especially if i had to stop fast. so i just adjusted the rod out to its max and bent it upwards. that seamed to fix my issues for the most part of premature lock, i can still do it if im not careful or in a panic stop but yeah

i know its not the same symptom here but i also noticed that the truck stopped nose diving as much after i did that so fwiw...
 
the kid said:
how much lift do you have? i know on my old 85 pickup i had to bend the rod, cause it would lock the rear brakes way to prematurely and send my a$$ end out especially if i had to stop fast. so i just adjusted the rod out to its max and bent it upwards. that seamed to fix my issues for the most part of premature lock, i can still do it if im not careful or in a panic stop but yeah

i know its not the same symptom here but i also noticed that the truck stopped nose diving as much after i did that so fwiw...
Click to expand...

3 inch OME 890's. Just an FYI, been doing it since stock 99 2WD springs.

The thing is, mine is already stuck at max, but my brakes suck in the back. I tried both all the up and down, no difference...

I appreciate the knowledge though. I want mine to do that!
 
http://www.autoshop101.com/forms/brake08.pdf

Page 98

After that read, I am fairly certain something is wrong with mine, then.

It clearly shows the LSPV rod at a lower position when unloaded, and all the way up during a loaded position.

Since mine is ALWAYS at the upper position, is it safe to assume mine is busted? It seems like the only explanation I can come up with.
 
ChildrenOfBodom said:
They're set to low
Click to expand...

ok.. good.

Could be the LSPV...

I dunno much on it other than it's main operation. Troubleshooting and figuring out if it's messed up is beyond my technical support. I know these aren't usual things you see go wrong on our vehicles though.

Good luck.
 
Last edited:
We just tried to do a delete of this valve for DOUS and this system seems overly complicated. There is one line that runs from the the master to the rear LSPV, there is one line that goes to the axle and then there is a third line that goes to the front brakes.

We didn't have enough supplies to remove it. We dissconected it and zip tied it up to body. We tested it and it stopped 100% better. We even tried to do some panic stopping to see if the rear would lock up and it did not.

If you want to do a delete, you will need a union and a plug. The brake lines are 10mmx1 so getting these parts might be hard to find. I think you will have to get 10mmx1 adapter to a 4AN fitting and then get a cap for that.

Remove the LSPV, install union to connect the master to the rear axle. Then , in the front, remove the return line from rear to the 4 way splitter under the master cylinder. Replace with plug. Bleed and test, This procedure should work especially well when you do the tundra brake upgrade.
 
I wondered if my LSPV was not functioning correctly when I first got my Runner, but my lift helped my nose dive so much that I just attributed it to worn out shocks. If you have that lift and the same nose dive then something is definitely wrong.
 
durrell said:
I wondered if my LSPV was not functioning correctly when I first got my Runner, but my lift helped my nose dive so much that I just attributed it to worn out shocks. If you have that lift and the same nose dive then something is definitely wrong.
Click to expand...

Durrell, LSPV only came on 2wd 4runners without electronic traction control. You might be getting the nose dive because the the rear brakes need to be adjusted. Adjusting is easy. Pull up on the parking brake while going backwards. You might have to repeat until have better braking action.
 
Singtoe said:
Durrell, LSPV only came on 2wd 4runners without electronic traction control. You might be getting the nose dive because the the rear brakes need to be adjusted. Adjusting is easy. Pull up on the parking brake while going backwards. You might have to repeat until have better braking action.
Click to expand...

Didn't know that. Thought I had read on YT that it came on all 4R's. Good to know. Thanks.
 
Singtoe said:
We just tried to do a delete of this valve for DOUS and this system seems overly complicated. There is one line that runs from the the master to the rear LSPV, there is one line that goes to the axle and then there is a third line that goes to the front brakes.

We didn't have enough supplies to remove it. We dissconected it and zip tied it up to body. We tested it and it stopped 100% better. We even tried to do some panic stopping to see if the rear would lock up and it did not.

If you want to do a delete, you will need a union and a plug. The brake lines are 10mmx1 so getting these parts might be hard to find. I think you will have to get 10mmx1 adapter to a 4AN fitting and then get a cap for that.

Remove the LSPV, install union to connect the master to the rear axle. Then , in the front, remove the return line from rear to the 4 way splitter under the master cylinder. Replace with plug. Bleed and test, This procedure should work especially well when you do the tundra brake upgrade.
Click to expand...

I should do what the kid said, I will find a junkyard LSPV and swap them, because if his rear brake performance is better after being ziptied up, where mine is currently stuck, then I must need one.

Thanks Singtoe. Top plates worked great, too, btw, thanks for the extra nuts for the studs
 
Singtoe said:
Durrell, LSPV only came on 2wd 4runners without electronic traction control. You might be getting the nose dive because the the rear brakes need to be adjusted. Adjusting is easy. Pull up on the parking brake while going backwards. You might have to repeat until have better braking action.
Click to expand...

Thank you for posting they only come on 2WD, I was reading this thinking WTF, I've never seen one on my 4Runner! I know my 88 has it and my Tacoma had it but my 4Runner definitely doesn't.
 
OP: you can get a piece of 3/16X1" flat stock and make an extension to raise it back up to the stock location, thats what I did on my Tacoma and I made it a little longer than necessary and the brakes felt awesome after that.
 
You must log in or register to reply here.

Members online

Total: 327 (members: 2, guests: 325)

Forum statistics

Threads
278,309
Messages
3,554,075
Members
248,016
Latest member
Advally Service

Share this page

Trending content

Back
Top