LSPV replumbing with some ABS delete on an LX450 chassis (1 Viewer)

[Mieser]

Hello,

I need some help with some brake plumbing on my LX450 based project...



I am using the stock LX450/FZJ80 booster and master on the FJ40 firewall with a custom bracket and pushrod to a modded FJ40 pedal assembly.

No more ABS system in general.

I have deleted the ABS style plumbing on the front axle and will now be running a 1 into 2 branch fitting on the axle to each caliper. I think this is how the non-abs 80 front axle was plumbed from the factory.

My question is what to do with the rear LSPV. From what I can find, it had a return line that went to the ABS brake system? Can I just delete/plug that return passage?

I will probably convert the LSPV to a manual adjusted arm. The rear end weight of this little truck is VERY light compared to stock.

Anyone have any ideas?

Thanks for the help.

 

[JeepinPete]

I pulled the ABS and bypassed the LSPV on my 80. Panic stop the rears will lock up first. So you will need to seriously dial down the rear braking on your project. I wonder if the 80 LSPV will be enough. I'm no Toyota expert, but I seem to remember Toyota using a LSPV on their pickups, might be a better match.

 

[scottryana]

On your project I would ditch the ABS, and ditch the stock LSPV and just use a manual proportioning valve. By the way the truck looks great

 

[Mieser]

On your project I would ditch the ABS, and ditch the stock LSPV and just use a manual proportioning valve. By the way the truck looks great

All the ABS stuff is gone. I am just trying to replumb it now.

I've never had the best luck with aftermarket proportioning valves. The small npt adapter fittings always seem to leak over time.

I'd like to try using the stock LSPV. It does the same thing basically, but with a lever instead of a knob. I can always convert the arm to be manually adjustable with a little custom linkage.

My general question is still with the plumbing to the LSPV. Can I delete the return line? If not, where would I plumb it to?

 

[Mieser]

Doing more digging. It seems the 2nd line on the LSPV is more of a bypass that is plumbed into the front brake system?

 

[Mieser]

More answering my own questions I guess....

-The 2nd line to the LSPV that is plumbed from the front system is a pressure sensing. Basically my understanding is that if that port doesn't see matching f/r pressure it basically bypasses the internal metering system and applies FULL rear brake force. This is a front brake system failure system? So if you don't apply pressure you will always have FULL rear brake.

So....options....

1. I could plumb it like 'stock' basically Tee into the front system and run another line to the LSPV.

2. I could plumb a Tee in the rear feed line to apply equal pressure to both LSPV ports at all times. This basically tricks the bypass function. This would require only one long rear line. I can tee close to the LSPV on the rear section of the frame.

3. I could delete the LSPV completely and sub in an aftermarket unit somewhere in the rear brake system. Wilwood makes a knob control unit with integrated m10 bubble flare ports or regular 3/8 inverted flare ports.

1-2b. I could also convert the LSPV to a manual adjustable system, instead of a suspension height system.

Pondering.