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Prop valve...again!!


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I am stumped on whether to remove the height sensing valve on my rear axle. I know this has been beat to death but my searching has really only turned up a storm of differing opinion (not that this post won't).

 

What would happen if I just removed the valve and ran the lines into the splitter. I'm concerned about the braking performance, the ease (or difficulty) of finding a replacement if this valve goes south.

 

So far the problems are:

Bleeding procedure is screwy, I've tried the procedure of bleeding all four, then opening the front right and slamming on the brake to "shuttle" the prop valve, no difference. The pedal is fine, the booster is fine, the M/C is new (and properly bench bled). All the calipers, pads, shoes, springs and cylinders are brand new. No leaks. Rears are adjusted to a slight drag. Just crappy stopping power.

 

All the rubber hoses are new and the metal lines look to be in good shape. All the fluid is new & clear.

 

It's lifted 3", which affects the position of the valve, and I'm in the process of adapting it to be adjustable with a threaded rod and ball clips. Then the FSM says that anytime you re-set the valve you "must" replace the bushing.

 

It just seems that doing away with the whole thing would be easiest.

 

Sorry, second thread today, but I really need to finish this.

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Of course you have crappy braking. With a lift and the rear valve still in place, you have no rear brakes. Doesn't matter how well you bleed them, the height sensing valve shuts off the rear brakes when the bed isn't loaded down.

 

I am in the camp that says "dump it." You'll have full braking to the rear, all the time. If you find that the rears lock up prematurely, then you splice in a Wilwood adjustable proportioning valve in the line to the rear and set it where you like it. You can always dial in more rear brakes manually if you tow or hail a heavy load.

 

I do not advise just teeing the two rear lines together. Functionally that works. But it means you have twice as much brake line running from front to rear, twice as much opportunity for rust and burst lines, and it serves no useful purpose. I pulled out both lines, and ran a single new steel line directly from the front junction block to the top of the hose at the rear axle.

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Of course you have crappy braking. With a lift and the rear valve still in place, you have no rear brakes. Doesn't matter how well you bleed them, the height sensing valve shuts off the rear brakes when the bed isn't loaded down.

 

I am in the camp that says "dump it." You'll have full braking to the rear, all the time. If you find that the rears lock up prematurely, then you splice in a Wilwood adjustable proportioning valve in the line to the rear and set it where you like it. You can always dial in more rear brakes manually if you tow or hail a heavy load.

 

I do not advise just teeing the two rear lines together. Functionally that works. But it means you have twice as much brake line running from front to rear, twice as much opportunity for rust and burst lines, and it serves no useful purpose. I pulled out both lines, and ran a single new steel line directly from the front junction block to the top of the hose at the rear axle.

 

DELETE : Yes, I would run a single line to the main rubber hose, correct?

 

KEEP: An adjustable (or altered) rod would put it at the proper angle, no?

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An adjustable (or altered) rod would put it at the proper angle, no?

 

Yes. Since you're in Cali, your load leveling valve should still be in good operating shape. Fitting a new adjustable rod is easy and cheap. I'd try that first and see how the brakes perform. The length of the rod must match the lift. If it's adjustable you can tune the rear brake bias it in to your preference. :cheers:

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Get rid of it. I killed one caliper on the front of my mj because of my rear valve being all screwed up. After I got rid of it and just ran a brake line to the back, I couldn't believe how much better the brakes were, I'm actually comfortable driving it down the road again, (before I would stay about a mile back from every one so I had plenty of time to stop)

Like Eagle said, you rears will wanna lock on you sometimes, but it makes you pay attention to your driving :D

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