qdude79

Hey All-

Just installed 1.5" coil spacers in the back of my '90 Runner 2wd and have some questions as to how best utilize my rear brakes, considering two things: 1) the coil spacers 2) 18+ year old coil springs.

Reasons: It seems simple. "Add 1.5" spacers, raise LSPV 1.5"." But, what about the fact that my springs have probably dropped some over the years (hence the need for the spacers)?

Better question IMO, how can I test my LSPV to see that any adjustments I make to it to accomodate my "new ride height" are making it functional?

Laymans terms: how do I know when my rear drums are working to their potential?

Jay351

Make a small bracket and lift it up. I didnt think mine worked at all but it did!

If your truck dives to the front alot during braking chances are your rear brakes are hardly working. If you raised your truck 1.5" from its saggy state then make your lift bracket around 2".

iamsuperbleeder

With only 1.5" lift, you may be able to get away with the redneck way and just rebend it, lol. I put on new shackles and did the same thing, no issues here, but the right way would be to make a bracket and raise the mounting point on the axle as mentioned and shown above. As far as compensating for the droop from aged springs, how far to you think it's sagged down? Add 1.5" to that, and that's how much your bracket has to raise the bar up.

abecedarian

the LPSV shouldn't need adjusted if the ride height is stock.

dirtoyboy

You really need to adjust it for safety reasons........having your ass end end up in front of you is not cool.....

The proportioning valve is designed to prevent rear wheel lockup during panic braking. The most important point to understand about proportioning valves is when they work - only during panic braking. This means that a vehicle could potentially go its whole life without ever using its proportioning valve.

Go to a gravel road with an assistant and get the truck up to about 20-25 mph and hit the brakes...have your assistant watching to see which (front or rear) lock up first and adjust the heigth of the LPSV accordingly. You want the fronts to lock up just before the rears

mt_goat

I test my brakes on a rainy day on an asphalt road. If the rear locks up before the front I adjust the arm lower. My arm is cut off and wired in place from the bottom of the bed (I know "redneck" right? )

dirtoyboy

Hey, whatever works! I usually recommend removing the LPSV completely and replacing with a Wilwood Proportioning valve. Eliminates the LPSV and return brake line completely simplifying the entire system.

Red_Chili

If Roger Brown does it, it ain't redneck.

With larger tires the LSPV is virtually worthless. Doesn't help that the rear brakes are just OK. LSPVs DO affect normal braking as well as panic braking.

I did what you did. When I went to a full floater and disks I also went with FRORF's manual prop valve which works REALLY well and very precisely.

thook

X2....

If you've added the spacers to remedy a sagging rear end and all it's done is returned the vehicle to stock height (or even a tad more than that), then there's really no need to mess with the LSPV.

I put some added coils on the rear leaf pack of my '86. Gave the truck maybe a 1/2"-1" of rake towards the front. My braking power and load distribution is still great. Could be a little better with a heavy trailer, but that's a heavy trailer for you.

latitude777

Please forgive me for my need for clarificaiton but its taken me ages to get as far as finding out i even have an LSPV let alone that it needed adjustment. I found out the hard way the other day when i needed to smack on the anchors in the wet when the front dived and locked up while the rear happily plodded away doing NOTHING! Luckily no-one and nothing was hurt..

So i bought the truck (1991 4runner 3.0 V6) about a month ago already with 2 inch body lift, some sort of aftermarket suspension kit (which is quite old by now) and has another 2/1/2 inch rear spacer going into it this week. Im trying to figure out how much i need to adjust my LSPV by to compensate as im guessing the aftermarket springs were 2 inch lift are now only maybe 1 in the rear...

Do i need to adjust by body + spring+ spacer meaning a total of 5 inches or.. Just the spring and spacer adjustment meaning only 3 inches?

I looked at the picture above and mine seems to be different.. Sorry for the late correction.. Is the circled item my LSPV? And seeing as though im changing to an adjustable panhard rod in the next couple of days.. Where do i mount it? Adjust it to etc??

Any help would be awesome thanks guys!

mt_goat

Nope, that is just the adjustment for it. The LSPV is at the other end of that rod.

latitude777

Ok so forgive the idiot!! (ME!!!)

Turns out after i did some looking about on my own truck and the panhard rod which recently turned up that i do have a bracket already there which will raise the LSPV sensor up about an inch. If you look at the adjustment that is already there, i'll get another inch.. If i get stuck after that i'll just add a small piece of flat bar and extend it higher. Sorry to take up space on the thread for nothing! Will post pics of the result.

RustBucket

iTrader: (1)

Keep in mind the space in your fender well is not important. It's the distance from your frame to your axle.

latitude777

Cool thanks mate! A 2-3 inches adjusment should do it then.

RobD

I adjusted mine right out from under my truck. Removed the line for the front proportioning and ran a new line for the rear brakes.

Magnusian

PO of my truck replaced the slagged LSPV with a manual valve mounted along the firewall though I think I'll be moving it to an in-cab location when I replace all my hard-lines with stainless.

Flash319

Rip it off and throw it in the garbage. DDS (Don't do @#it)

Flash319

[oops

latitude777

Wow how slack have I been? I managed to do the LSPV mod and havent had any probs what so ever with my brakes since. Adjusted the lspv almost all the way up included a flat bar extender upwards and all is sweet. Work great on and off road and everything seems to be going sweet. Oh and i dropped a braided extended brake line in the rear for good measure though you wont see it in this pic.

Oh i also threw in some Rancho shocks to go with the 2 inch lifted springs and 2.5 inch coil spacers (soon to be replaced with 80 series landcruiser coils).

thook

Just as a point of reference, and since I didn't see it mentioned anywhere, one can adjust the LSPV by also dropping the height of the valve body on the frame rail. IOW, you can raise the height of the spring by adjusting the bolt on the axle, but you can also lower the valve body position to get it to work right with a suspension lift.