Leaking Load Sensing Proportioning Valve (LSPV), '79 pickup (1 Viewer)

[MrClean]

It's been leaking a little for months, but I came out today to find a large puddle of brake fluid. It appears that I am missing parts to this that would actually make if function properly (see pic). Isn't there supposed to be an arm that attaches to the LSPV to allow for it to sense a load? Anyhow, I'm posting this to ask what the general consensus is on these devices? I've read a number of posts where they just remove it entirely and then I've read a number of posts where an aftermarket manual valve is installed (Summit, Willwood, etc...). I don't plan on really hauling any large loads and the brakes seemed to work fine before this failure. Would I even notice any difference if an aftermarket valve were installed? Thanks for any input.

 

[toyotaboy80]

Yeah, theres supposed to be an arm and lever that changes the output of the valve based on how much weight is in the bed.

Mine was pretty rotten and I have zero intention of installing the OE set up.

My plan is to delete it, plug the return port at the front brake junction, and run my rear brakes hardlined direct off the master. If I run into an issue where I have too much rear brake, I'll put in a dial adjustable valve somewhere at the firewall. I have the v6 upgrade front calipers. Unless I do rear discs, I dont think I'll get too much rear brake with the drums.

I'd recommend you just delete it and reassess later whether you need to turn down the line pressure. OR just install the valve when its all torn apart... worst case you didnt need the valve and just run it wide open.

I have my doubts anyone ever needs adjustability in the rear brakes on this truck, unless the adjustability was to tune down the pressure to prevent rear lock up before the front locking up. Load wise, if your front brakes werent going to stop you, you were probably fk'd anyways.

Edit: looking at your valve, doesnt look like it has the return to the front brakes...?

 

[gnob]

Early doesn't have the return line.
OP, Just delete the valve. One of the best free Toyota mods.

 

[yotadude520]

I second deleting it completely. If you'd like you can put a manual proportioning valve in it's place but that's up to you!

 

[Manhattan]

I've been considering deleting Patty's arm/valve. Currently, the spring (lever) is out of the axle bracket and zip-tied in a position to mimic a load... Hard to tell if it made a difference. The back of the truck is currently so light that the tires lock up pretty easily.

Was that valve every useful - like when it was new, the truck was stock, etc.?

 

[gnob]

It is/was a band aid for people who can't drive.
When Toyota brakes feel like shyt, this is typically the most common issue.
That or improper adjustment of rear shoes.

 

[MrClean]

Thanks for the responses. I'm going to just remove it like ya'll said. Hopefully that will be one less drip on my garage floor...