Load sensing brake prep. valve. upgrade/removal?

[GrimmJeeper]

tbburg have you looked into a better friction material for the stock drums? The rally guy that used to run the MJ has a thread going about brakes in the JS subforum, he mentioned a more aggressive rear shoe material that was available.

 

[cruiser54]

tbburg have you looked into a better friction material for the stock drums? The rally guy that used to run the MJ has a thread going about brakes in the JS subforum, he mentioned a more aggressive rear shoe material that was available.

Excellent idea. Go talk to the guys at Arizona Brake and Clutch, near I-17 and McDowell. Perhaps they still do VelveTouch or an equivalent. If they turn the drums and arc the shoes to the drum with a better friction material, you'd be fine, and legal.

 

[tbburg]

Upgraded shoes are in the works. They're not rare, just not as well known as disc pads now that almost everything uses 4-wheel discs.

I only mentioned the swap possibilities in response to badron's questions, to clarify the rules we're operating under.

As of now, I'm planning on late Cherokee booster and master cylinder, true split plumbing with a stand-alone adjustable proportioning valve to the rear, possibly adjustable from the driver position. I was planning on EBC pads, but right now there's an active thread in the Jeepspeed forum that has opened my eyes to a couple other possibilities.
Planning on sticking with factory rotors. I'll see how that works as I go along.
I already have the 10" drum set('87 D-44, lucky, lucky,..)

 

[xjtrailrider]

I have a question!?!

If I do away with the load sensing valve and I have a prop valve under the MC, why do I need to swap prop valves? Cant I just hook my rear brakes to the line coming from the MC and do away with that load sensing craptastic stuff?

I hate to go through the trouble of replacing the prop valve if i already have one from the factory.

 

[cruiser54]

Your rear brakes may lock prematurely unless you swap in an XJ prop valve. That being said, I disconnected the link on my rear prop valve, pointed the lever straight up and zip-tied it into place giving full pressure to the rear brakes, and I'm happy with it. I reversed teh procedure just to double check and felt my brakes were poor. Zip-tied it back up. Try it and see.

 

[cracker]

I have a question!?!

If I do away with the load sensing valve and I have a prop valve under the MC, why do I need to swap prop valves? Cant I just hook my rear brakes to the line coming from the MC and do away with that load sensing craptastic stuff?

I hate to go through the trouble of replacing the prop valve if i already have one from the factory.

Some have removed it and ran with the OEM distribution block. Others have swapped in a XJ prop valve.

If you are running drums in the back you may want to swap it for an XJ but if you have discs you might try it with the distribution block. Let us know what you come up with.

 

[cruiser54]

Good advice^^. I have the Dana 44 with the larger shoes and I like it.

 

[xjtrailrider]

I swapped in a 8.25(SUA) so it has the smaller drums. After more thought, I might just make the load sensing craptastic valve work again by making a rod for it, right now its just pointing to the ground! It stops fine like this though.

 

[cruiser54]

I swapped in a 8.25(SUA) so it has the smaller drums. After more thought, I might just make the load sensing craptastic valve work again by making a rod for it, right now its just pointing to the ground! It stops fine like this though.

Take the time to point the lever up and drive it before fabbing u a new rod set-up. Maybe your valve is bad for all you know. Mine's good as ther is quite a difference in how the brakes work if you move the lever. It would be a shame to make a rod for it only to find it's crapped out..

 

[cracker]

I swapped in a 8.25(SUA) so it has the smaller drums. After more thought, I might just make the load sensing craptastic valve work again by making a rod for it, right now its just pointing to the ground! It stops fine like this though.

Be careful. There have been MJ owners experience that load sensing prop valve explode under extreme braking. I think Eagle experienced this once.

 

[oldseddie]

The problem with the load sensing valve is that when you nail the brakes the front end dives and the back end raises. This causes the valve to think the bed is empty and close off the rear brake line pressure. It stops much better with it disconnected and adjusted for normal loads.

 

[xjtrailrider]

The problem with the load sensing valve is that when you nail the brakes the front end dives and the back end raises. This causes the valve to think the bed is empty and close off the rear brake line pressure. It stops much better with it disconnected and adjusted for normal loads.

This is what I will do then. Is "level" at the lever considered normal operating level?

 

[cruiser54]

I'd have to look in my Comanche manual to verify it. Just play with it. Like I said, I just flipped mine up and zip-tied it. Go do a road test afterwards so you know how it acts.

 

[xjtrailrider]

I'd have to look in my Comanche manual to verify it. Just play with it. Like I said, I just flipped mine up and zip-tied it. Go do a road test afterwards so you know how it acts.

Will do then, we have been driving it with the lever hanging straight down, it stops but it nose dives badly.

 

[cruiser54]

Well, hopefully it won't nosedive and will stop better for ya by putting the lever in the up positon..

 

[oldseddie]

The lever is attached to the valve with a plastic button which has splines cut in it by the lever. Once you find the sweet spot remove the lever and reposition it straight up and zip tie it to the valve.

 

[xjtrailrider]

The lever is attached to the valve with a plastic button which has splines cut in it by the lever. Once you find the sweet spot remove the lever and reposition it straight up and zip tie it to the valve.

Good info, Thank You!

 

[Rejeep]

hate to re hash such an old post...
but does anybody have any conclusions on this as to what they found works best?

I am looking to replace all the lines on my 86 and want to do away with the non operable rear valve...
I was going to throw a simple T block in there and just be done with it and upgrade my proportion valve once I decide on a rear end brake setup (drums or disks)

 

[cruiser54]

www.comancheclub.com

 

[Rejeep]

yeah Im on there.. been for years...
I just googled the question and found this thread with a lot of comprehensive info...