Load sensing spring

[KLF]

What happens is the LSPV has 2 lines coming from the front of the truck, then one output to the rear axle. One of the lines from the front is there rear brake circuit, the far left line in the above photo. When the LSPV is doing it's job and reducing brake pressure to the rear brakes, it has to bleed the excess pressure off so it sends the excess pressure back up to the front brake circuit. That is the line you see connected to the left on the T. If @yotadude520 looks at that T on his truck now, he will see a plug in the T there, I just cut the end off the line, folded it over and soldered it shut. The rest of the line was never installed when I was putting the truck back together. So the rear circuit line just has a simple coupling above the rear axle then there's another piece of hard line that extends and connects to the hose for the rear axle.

Very simple.

 

[gnob]

Even simpler if you bypass the "t" by running the front line to the caliper. Then the rear line from the "L" goes back and connects directly to the rear soft line. No extra plugs, couplers needed.

 

[ntsqd]

Simpler, yes, but Mr. T anchored the lines there with both the 'L' and the 'T' on that bracket for a good reason. Rare that he does something like that where re-designing it results in a better system.

If the LSPV's effectiveness range were larger I'd argue strongly for keeping it.

 

[gnob]

Right, like capturing the clutch hardl line with the starter bolt bracket. Straight genious. While i respect Toyota in general, i dont have much respect for design engineers.

 

[ntsqd]

Like any other profession there are those who are good at their job and there are those who are bad at their job. As an Engineer myself (I currently design manufacturing tooling for production lines, but I started out in Engineering designing brake parts at wilwood) I see a lot of disrespect for designs that the person doing the disrespecting clearly has no understanding of why it's like that. So their first thought is that the designer is an idiot. Maybe and maybe not. Sometimes there are good, but counter-intuitive reasons why something that seems dumb was designed the way it was. And sometimes the designer is an idiot. Looking for why a design that seems dumb is designed the way it is has made me a better designer.

 

[jgranthevagrant]

Spent Friday bolting things back together and then bleeding. Road tested well, so put it through some local torture tests called the Duffy and Seton Portage. No brake issues, but I will keep looking at a solution to the LSPV and the spring, which now has torn boots.