Mudders hate him! 1 weird trick to fix the LSPV (1 Viewer)

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Hmmmm. That factory load sensing proportioning valve adjusts the brake power to the rear wheels based upon the traction they have. It does this by INCREASING the brake power to the rears when the suspension is compressed, and DECREASING the power when its empty. By eliminating it (vs having an operating LSPV), your fronts will tend to lock up at max braking when loaded, and the rears will tend to lock up when unloaded. In normal driving and some gravel road testing you may declare victory with this mod. The first inkling it was a bad idea will be when you are doing an emergency evasive maneuver to avoid something for real, and the rear end comes around. If you're really, REALLY good you will catch it and merely end up in the oncoming lane yelling 4 letter words and heading back to your lane. And if you're really, really LUCKY you will not center punch 3 teenage girls in a Nissan Sentra and kill them all. If that happens, and during the modern forensic examination of your vehicle that happens nowadays they discover you eliminated a device meant to help in emergency braking maneuvers, you will get shelled. And deserve it.

I get it. The LSPV broke and the first try did not fix it. But that's not a good idea and shouldn't be sold as one on a public forum. I have personally driven vehicles on proving grounds during brake system development and there is a damn good reason for that feature on a high CG vehicle.

Doug

I know that, in theory, you are right. I challenge you to go set the LSPV in the max load position and do some hard stops on gravel (safety third and all that). Tell me I'm wrong. I personally think that the transfer case drag (even when unlocked) renders the brake bias moot. The reason I say this is that I have manual hubs on mine, and when they are unlocked the front tires lock before the rear. When the hubs are engaged, all four squall at the same time and I can kind of feel the rear end squat more. Maybe it's just my rig, I dunno.
 
My ass end comes up under Hard Braking, after reading all these responses I wonder how a guy or gal is to know when to replace or adjust the LSPV? My ass end also sags I which makes me more curious as to whether or not its working properly if it thinks that I am always under load.
 
Correct if I am wrong, but I thought the normal/proper functioning went out the window as soon as we started modifying our trucks with lifts, heavier duty suspension, etc.? So if the LSPV can no longer operate as designed, then what additional harm are we doing by removing it?
 
No ABS and LSPV bypassed, and ha e always felt safe in some pretty sketchy situations. A couple of them I likely wouldn't have stopped if the rears weren't getting the higher output they now are. Each rig is different, based on weight, ride height, and driving/braking style. Do what works for you, without making safety an issue!
 
I have a 91 80 and upgraded my front brakes to the newer dual calipers. Will this mod make more of a difference in the valve delete? Has anyone towed with this mod? I too have tried to adjust that wretched valve and have given up. I know for a fact that I could get better breaking out of this pig even with 37's.
 
I keep reading about folks making their tires chirp while breaking....never happened to me.

I have even gotten up good speed on a private road, then stood on the brakes. She just comes to a stop in a very mannered fashion. No squeal, slip or clicking from ABS.
 
Hmmmm. That factory load sensing proportioning valve adjusts the brake power to the rear wheels based upon the traction they have. It does this by INCREASING the brake power to the rears when the suspension is compressed, and DECREASING the power when its empty. By eliminating it (vs having an operating LSPV), your fronts will tend to lock up at max braking when loaded, and the rears will tend to lock up when unloaded. In normal driving and some gravel road testing you may declare victory with this mod. The first inkling it was a bad idea will be when you are doing an emergency evasive maneuver to avoid something for real, and the rear end comes around. If you're really, REALLY good you will catch it and merely end up in the oncoming lane yelling 4 letter words and heading back to your lane. And if you're really, really LUCKY you will not center punch 3 teenage girls in a Nissan Sentra and kill them all. If that happens, and during the modern forensic examination of your vehicle that happens nowadays they discover you eliminated a device meant to help in emergency braking maneuvers, you will get shelled. And deserve it.

I get it. The LSPV broke and the first try did not fix it. But that's not a good idea and shouldn't be sold as one on a public forum. I have personally driven vehicles on proving grounds during brake system development and there is a damn good reason for that feature on a high CG vehicle.

Doug

This is true and Mr T did this for a reason with lot's of testing, but doing a Mod like this IMHO is not good for a DD, and if you live where the weather greases the road with ice a rear lock up and you are in a ditch, and the ones here are really really deep, and of course there are other people on the road, in which you may hurt or kill someone and with a simple search from a bottom feeder they will find info on you garage re-engineering of a proven brake system :meh:
 
sorry man, way too long ago to remember. I forgot i even wrote this post. blast from the past for sure!

sadly that 80 series is long gone from my driveway :(
 
sorry man, way too long ago to remember. I forgot i even wrote this post. blast from the past for sure!

sadly that 80 series is long gone from my driveway :(
Smart move gas prices are pretty rough these days.
 

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