dwh91102

Couple questions about removing the porportioning valve. I just finished up doing the chevy swap on my rear, and was going to do away with the lspv, but after some research have a few questions. I've read about it being done both ways, 1 without a aftermarket manual porportioning valve, and 1 with it. I'm looking for anyone that has done this mod (either way), and has any pics or feedback about how it works. The main thing i'm having trouble with is what the guys are doing to the "high pressure return line" at the front, most of the write ups I read weren't very clear. As alway I really appreciate any help you guys can provide.

dwh91102

I hate to bump this, but this is one of the last few bugs to work out of my build. Thanks guys

wrenchmonster

I've never done the particular swap you are talking about, but I would suggest going with the proportioning valve. I'm assuming you know its function. That said, wildwood sells a racing, adjustable proportioning valve that is very nice.

dwh91102

thanks, waskly got me straightened out lol

snap-on

i was going to say, there was a recent artical in petersons were they did this on a yota truck

if you look at the passanger side wheel well at the back, on top of the frame rail youll see the T fitting were the high presssure return line ties in.

If you remove the rear LSPV then you can remove the return line, use a coupler in the rear to run right from hardline to hardline, then put your new wildwood manual proportioning valve up in the wheel wheel instead of the T fitting. as 1) you can use the new valve as the splice, 2) its relitivly easy to get to inorder to tweek the setting and 3) its out of the way.

dwh91102

thanks snapon, thats basicly what brian did, he just has his mpv up by the mc. The articles I found online weren't really sayin what they did with the return line.. Thanks for everyones help.

4runnerluver

I would love to know what everyone has done with the proportioning valve issue. I am at this stage in my 4Runner rebuild and have heard arguments for keeping, replacing or getting rid of it completely. Please explain what you have done, what the results are and if you would do anything differant... Thanks in advance!!!!
-T

tc

I got rid of mine in favor of a manual one, and the brakes have never worked better.

BigBluePile

iTrader: (3)

I use a manual valve by the MC. Works great.

abecedarian

What return line? There isn't a return line on the LSPV.

abecedarian

there's a pressure line from the rear brake circuit
there's a pressure line from the front brake circuit
and a distribution line to the rear brake cylinders....
where's the return line?

red97taco

x2

I don't know if it is the same for your trucks, but the tacomas do have one. There are two lines that run from the driverside all the way back to the lspv. One of them goes from the master cylinder to the lspv, the lspv takes this pressure and adjusts it according to the load(weight in the back of the truck). It takes what pressure is needed and puts it towards the wheel cylinders. The extra pressure from the lspv is then redirected towards the front brake circuit through the return line(maybe it is not called a return line). It goes through this second line, and enters the front circuit at the T fitting for the driverside front brake line.

tc

Do a search - someone had posted a great picture of the whole system that worked great when I was looking at mine.

But, to sum up, red97taco has it right.

Also, if you put in standard proportioning valve and eliminate that return line to the front, you will have MUCH better isolation between front and rear.

Flash319

I yanked all that crap off and ran new lines from the master to each front wheel and one to the back wheels. All the ABS and LSPV gone. Works great. This is on my Pickup and I have no problems with the back locking up. Those aftermarket valves are not "proportioning valves". They are flow control valves and just delay the back brakes until the weight of the truck shifts forward.
I am in the middle of doing the same thing to my 92 Runner because all those lines are rotting off.

4runnerluver

Thanks guys! Your great as always... -T