One of the lines going to the LSBPV rusted through and burst right at the gas tank. Salt spray off the right rear tire was likely the cause. I decided to eliminate the LSBPV and remove both old lines all the way to the front. 12mm socket gets the line holders off. The one near the rear of the tank was tough to get at but not bad.
I then noticed that my two short lines going from the brake line junction behind the RF wheel to the ABS (w/ power steering assist I guess?) box up front were just about to blow, were all wet looking... again likely from salt spray off the R CV joint. Lovely Maine winters! These lines are tough to see so remove your skid plate and look yours over if you are in the northeast!
I then ran a new line from the rear brake common flex line all the way to the ABS box (to the port on the driver side). I also replaced the line from the passenger side port of the ABS box to the L connector behind the RF wheel. I then plugged the left side of the T in that same area. A 1" piece of line, flared and with a new nut, and a small nail with a nice flat head (must be correct diameter) inserted into the tube works great as a plug.
Everything bled off great and breaks work ever better than before. Almost like the rear brakes were not working properly before, maybe LSBPV was faulty?
3/16" teflon coated tubing from napa was $20 for a 25ft roll and the metric end pieces were $1.20 ea. Make sure you have a double flare tool as well.

Thanks to this forum for the previous posts for me to search from. Excellent info, considering I did not know what a LSBPV was yesterday!
Later,
Ed

 

maybe i missed it but what did you put in place of the lspv?

 

Nothing. I just did the exact same thing for the exact same reason two weeks ago. I burst the hard line that runs just behind the gas tank (plastic clip had rubbed through the line).

There are two lines that run from the front, just behind the passenger side front tire. One has a T junction, on has an L. The L feeds pressure for your rear brakes and the T feeds pressure from the front to the LSPV. The LSPV (or more correctly, the LSBPV) allows more or less pressure to the rear brakes depending on load.

I, too, ripped it out, plus all the lines going to the back, clamped off the front line at the T junction, and ran new line (also from NAPA) all the way back to the bracket for the the LSPV. There is a rubber brake hose (which I replaced, since I was there) from the bracked to the top of the rear diff.

I now have way more braking force than ever (and the rear ABS keeps the back in line, for those of you who were worried about having too much rear braking force). It stops way, way better than it did before the line went out. You could put in a manual proportioning valve to keep the backs from skidding past you.

 

Right on RobD, aye. The L junction actually goes through the ABS/power steering assist module and then a homerun line to the rear brakes, which you know, I just wanted to clear it up for others.
No excessive braking in the rear that I can tell on tar. My ABS light does not come on so I trust they are works ok for the rear. Will see how she handles in the snow. The brakes are more touchy, since they actually work now, so it will be different this winter!

May end up selling it by then and going back to jeeps.... I know, I know, but these things are a PITA to work on! Up north where I am they just rust too much.
Ed

 

Hey Ed, I can almost guarantee you will notice a big difference on snow... you should sell that runner to me so you dont have a wreck...lol

 

I can actually get the rear ABS to engage on dry pavement at 60 mph, something I never, ever felt it do before. I used to get it to activate a couple times on gravel and snow, but the rears actually feel like they're doing something now. I no longer time my braking with a calendar.

 

I am just getting ready to go through the exercise of replacing the brake lines to the rear.

So, basically by eliminating the LSPBV, I can basically cut my work in half (from 2 runs to 1).

What is the downside to bypassing the LSPBV?

Thanks

 

The downside can be a potentially huge one. The LSBPV varies the amount of pressure to your rear brakes. If there is no weight in the back of your truck, it allows for less pressure to the rears, keeping them from prematurely locking in a hard brake application and then allowing your back end to out-run your front end and put you into a nasty rear-wheel skid.

Now, I did the removal for a couple reasons. Like you, I wanted to cut my work load in half, so pulling both lines to run one seemed easier. But the other reason is that I plan on doing the rear disc upgrade at some point and was going to put in a manual proportioning valve (which you can still do if you want control over your rear brakes).

I've found that the ABS is doing a good job so far. I've done several hard brake applications on dry, wet, and gravel roads getting a feel for how it responds. The brakes grab way better than ever, so I'm not going to change anything at this point.

That might all change, however, when the snow and ice hit in a few months. I will re-evaluate then.

 

Thanks for the response.

It looks like $40 for the summit manual adjusting valve may be worth it.

 

I don't get why everyone ditches the LSPV. Its there for a reason. I don't know about other people, but I carry 500lbs of cement and lumber one day and my 5oz. fly rod the next- often in the rain. The LSPV is sort of critical for me.

 

I ditched it because it was going to be a pain to route two lines to the back, plus I wasn't sure it was even doing anything.

I have rear ABS and wasn't really worried about having more rear-bias. I have way better brakes now than I did before.

It's a personal call. There are ups and downs to it and I wouldn't recommend it for anyone without rear ABS.

 

Matt16 -There are several reasons why I am doing this:

1. Less work (I am essentially replacing one line instead of two);
2. Cost of manual proportioning valve v. toyota replacement;
3. original is completely rusted, rotting off the frame and won't give up one of the brakeline ends;
4. from what I have read, it appears that the manual proportioning valve should function similarly to the original toyota valve;
5. even if replaced with a toyota valve you still need to set it up with gauges whereas with the manual valve positioned next to the master cylinder you should be able easliy make adjustments (I read in a post that is should be set at 65-35 split (front-back) in pressure.

If I am misinformed or have misread the posts, please let me know.

Thanks

 

You're right with most of your points. The only thing that is a tad incorrect is that the LSBPV actually does the proportioning automatically, dependent on load. Your manual proportioning valve is...well, manual.

I didn't bother with one. I'll consider it if I ever do the read disc upgrade. Right now, though, I'm more than happy with the way they are.

 

I bled the brake lines now it sounds like the master cylinder is sucking air. The pedal is soft.

Does this mean my master cylinder is done?

 

How did you order or even find the LBVPV at the parts store, I have been looking for one and can not find it for the life of me.

 

The LSPV is a dealer only item and very expensive.

they just removed them.

Back in the day one just learned to drive with the empty pick up and watched your speeds on wet roads.

The LSPV was for clueless drivers just like abs brakes my opinion

This is a very old thread so doubtful if anyone will respond.

 

Don't get me started about peoples skills behind the wheel, or rather lack of.
It also seems that gone are the days when people tried to avoid an accident long before it happened by looking far ahead of them, having situational awareness, and having their full attention dedicated to driving.

Who'd have thought all those stupid driving scenes in CHiPs would've come true.