hmm, i think your best bet there would be to just remove the anti-lock brake system a long with the LSPV.

 

I have V6 Calipers in the front of my 87 4Runner and the LSPV pulled all the way up and my front brakes always lock up first. It seems like my rear brakes barely work. I prolly need to put the manual proportioning valve on to help fix this problem.

 

Or...

• The LSPV isn't functioning correctly, aside from being essentially by-passed.
  
• The brake shoes need adjusted.
  
• The brake shoes and/or drums need replaced.
  
• The brake drums are full of brake fluid(leaky wheel cylinders).
  
• The brake drums are full of gear oil(leaky axleshaft seals).

If not, then...

• Everything is working just fine, the front brakes should lock up first/before the rear.

I've never heard of anyone needing to install a MPV after just a front V6 caliper upgrade.

 

Old thread!!! but still, good info

 

k i gotta question about the LSP-BV. i have a 94 with a V6 4x4 and 4wheel abs on it and auto trans, im having an issue with the pressure at the rear wheel cylinders. i had a suspension that they were not stoping the truck so i raised it put it on stands, put it in drive and brought it up to 40Km/h, hit the brakes and they nearly stopped. they still turned, no matter how hard i pushed on the pedal, i let off, and pushed slowly, felt a slight pop in the pedal and then this time it actually stoped them.

now 2 years ago i replaced the rear lines, due to rott, stupid routing if u ask me was the reason for failure, anyway i think i might have messed up which line went to what hole in the valve, if someone knows if the routing is different bewteen the 90 and 94 years, plaease let me know, thanks

 

https://www.yotatech.com/forums/f77/.../#post51131879

 

Corax, so this would mean that you could set up the brake pressure distribution by that knob in the pic and drive it safely as is? (kinda like the simple and effective braking systems used on 'older' domestic vehicles?). I have a couple bad lines on my truck with other lines that are still in great original shape inches away, but I have a feeling the bad ones aren't coming out easily if at all
I'd like to just eliminate the retarded factory braking setup and start over with a simple/effective design which I know is possible since any other vehicle I've owned didn't have any issues set up simply the way they were.

 

Exactly, dial in you brake bias once and drive it. I haven't had to mess with the adjust since the day I installed it.

 

Just a little update. I stole the proportioning valve off my Chevelle before a weekend wheeling trip. It was the best thing I could have ever done for the brakes. It has a better pedal feel and stops about 100 times better.

 

I know this will bum some people out, but I would seriously LOVE to swap everything over from a 1998 ext cab Z71 so I could just have my old truck back. Like an idiot, I traded off my old truck to get a more 'economical' truck thinking that toyotas run forever, blah, blah, blah. I can't seem to get more than 15 mpg out of my '95 'ext cab' 4x4 5 speed toyota and that comes with problem after problem of things not working correctly or not at all I know all used vehicles have their problems, but this truck seems to have issue after issue due to cheaply designed parts or it's primitive design in general.
I realize the truck isn't brand new, but I figured with 'just' 121,000 miles I would get another 50,000 more at least. I read about the problems MANY have had with the "3.slow's" head gaskets failing and that worried me at first. Now, thanks to all the other problems this truck seems to have, I have completely forgotten about worrying about the head gaskets. Parts are way too expensive IMO for these trucks also compared to what I am used to paying for any domestic vehicle I've ever owned. And trying to get over the culture shock of working on a foreign vehicle makes it all that much more frustrating, for me anyways.
These little trucks seem to be a great light weight design for playing in the mud/etc, but I just really need something that will drive me to work every day without yet another cheaply made/poorly designed part/feature failing.
Toyota's are great for some people I'm sure, just not me.

 

Ive never found the lspv to ever work properly after any kind of suspension lift. Ive just got the rod caught on trail obstacles and bent it all up anway. On my 84 pickup i simply dissconected the linkage up to the lspv unit under the bed and i still have decent braking back there even with 40" irocks. I just recently removed the same rod up to the unit in my 92 4Runner as it was all bent up after snagging on a branch and i noticed the rubber dust boot was leaking a very small about of bake fluid. After removing all the hardware up to the unit i cleaned it up where gunk was built up and havent noticed any fluid leaks since. My rear brakes have the same amount of pressure as they did with the rod hooked up in the first place. Alot of comments on here about how much of a huge difference it makes but between disconnecting two seperate units on two seperate trucks now i have noticed no difference what so ever at all. Just a cleaner look underneath with less crap to get ripped off when wheelin