MJ Load Sensing Valve Delete Procedure

[Goose_XJ88]

Ok so I just took a quick look at my LSV in my 92 and I'm a bit confused on the flat spot you are talking about.

 

I have not taken my arm off yet because I don't have time at the moment but the only flat spot I can see with it assembled is the larger portion behind the splines and that #1 sits on I think.

 

Is this the correct flat spot or is the correct flat spot I need to check not visible until you unbolt the arm?

[HOrnbrod]

You can't see it when it's assembled. Remove the LSV arm and bushing and you will see the flat on the splined portion of the shaft.

[Keyav8r]

Look at the illustration again. The flat is on the smooth section behind the splines (closest to the valve body). The edge of the flat is shown there. As Don said, you have pull the arm to see it.

The real trick is holding it in place while you put the arm back on. A thin open end wrench of the proper size will work best. And no, I don't remember what the proper size is.

[cruiser54]

Having done this mod in different ways, I'm gonna point something out to you guys. 

 

You are leaving a large amount of overall braking on the table when keeping the Distribution Valve. 

 

Your brake line inner diameter is .100". Stock.

 

Where the fluid for the front brakes passes through the Distro block, it is metered to .050". That's an area of .00196"

 

If you were to use a ZJ prop valve, which is metering the front brakes through a .078" orifice, and eliminate the LSV as a matter of course,  because you would use the prop valve to proportion rear braking, the area for the fluid to flow would be the area for the fluid to flow to the front brakes would be .00478".

 

If you use an XJ prop valve, which is metering the fluid to the front brakes through an orifice matching the brake line ID of .100", and eliminate the LSV as a matter of course because you would use the prop valve to proportion rear braking, the area for the fluid to flow would be .00785".

 

By allowing the fluid to flow to the front brakes through an area of .00785" versus an area of .00196". That's a lot!!!!!

 

I've tried it both ways. Now on MJs I ditch the distro block, T the front brake lines together, eliminate the finicky and kludgy LSV. An adjustable prop valve for the rear brakes is $40 at Summit Racing......

[HOrnbrod]

Cool, now I'm gonna point something out to you. I'm going to retain the kludgy LSV because I want to, I like it, and it's a good feature to have if you can retain it and still have good brakes. At this point I do, especially on the rear disks. LSV's have been used by many manufacturers on all kinds of vehicles and are still being used. And you are definitely an expert on kludges as you like Renix MJs, the ultimate kludge-mobile.  :rotf:

 

Good info on the small .050" MJ front brake ports though; I'll probably punch them out and see what happens. Might just bring the fronts up to par with the rears. However, it's not a high-pri at this point. 

[cruiser54]

I wonder if you can punch it out. And if you did, would it affect something else? 

 

You just don't know what you're missing...........

[HOrnbrod]

Unknown - good question. But being that the XJ prop valves w. rear drums are .100" and the ZJs with rear disks are .078", they must have made the MJ distro block front ports smaller to make up for loss in the rear MJ LSV over varied load conditions. Just my guess.

[cruiser54]

Unknown - good question. But being that the XJ prop valves w. rear drums are .100" and the ZJs with rear disks are .078", they must have made the MJ distro block front ports smaller to make up for loss in the rear MJ LSV over varied load conditions. Just my guess.

Are ALL the ports on the ZJ valve .078"?

All of them are .100" on the XJ prop valve.

[HOrnbrod]

 

Unknown - good question. But being that the XJ prop valves w. rear drums are .100" and the ZJs with rear disks are .078", they must have made the MJ distro block front ports smaller to make up for loss in the rear MJ LSV over varied load conditions. Just my guess.

Are ALL the ports on the ZJ valve .078"?

All of them are .100" on the XJ prop valve.

 

Will check tomorrow.

 

ALSO, I can not find the p/n of the MJ brake distribution block in any of the parts manuals throughout the years. Was trying to see if there are any differences between the Renix and MJ years. Any idea? Maybe the p/n is different since the rear proportioning brake valves were different. 

[Minuit]

The 91-93 parts book has 52002497 for MJ, 52006394 for XJ up to 3-1-93, and 52009108 for XJ after 3-1-93

 

The 87-90 parts book has 52002497 for MJ, 52000097 for XJ 87-89, and 52006221 for XJ 1990. So the MJ distribution block stayed the same at least 87-92 according to the book.

[Eagle]

 

ALSO, I can not find the p/n of the MJ brake distribution block in any of the parts manuals throughout the years. Was trying to see if there are any differences between the Renix and MJ years. Any idea? Maybe the p/n is different since the rear proportioning brake valves were different. 

 

 

My 87-90 parts manual shows  P/N T300 1235 for the MJ. And I don't see any listing for the MJ in the 91-93 parts manual.

[HOrnbrod]

Well, so much for the MJ distribution blocks being different.  Thanks all. 

[54bobby]

so help me out here. i am replacing both rear brake lines at this point cause both are rusted out. i wanna delete the load valve. so i plug the bottom or front port on the proportioning valve? 

if the line on the nose is lets say A, and the bottom is B, which do i plug and what do i do with the line? eliminate it? the line from the port that doesn't get plugged gets  the coupler in the rear and connects to the hard line that connects to the soft hose correct? 

so what i'm left with is the un plugged line running to the rear and connected to the coupler, that then gets connected to the hard line that connects to the soft line. everything else gets deleted right?????

ugh, i have a headache.

[cruiser54]

Ditch both the distro valve and load sensing valve. T the front lines together and use an adjustable proportioning valve for the rear. 

 

The best combo. 

[HOrnbrod]

That's the best only if you don't know how the load sensing valve works or how to make it work.

 

"The best combo."   :rotfl2:

[cruiser54]

That's the best only if you don't know how the load sensing valve works or how to make it work.

 

"The best combo."   :rotfl2:

You have no idea what you're talking about. 

 

Have you done it both ways as I have? 

[54bobby]

Ditch both the distro valve and load sensing valve. T the front lines together and use an adjustable proportioning valve for the rear. 

 

The best combo. 

by ditch the distribution valve do you mean the one by the MC? T the front lines together in the front or in the rear? 

[cruiser54]

 

Ditch both the distro valve and load sensing valve. T the front lines together and use an adjustable proportioning valve for the rear. 

 

The best combo. 

by ditch the distribution valve do you mean the one by the MC? T the front lines together in the front or in the rear? 

 

Ditch the distro valve. T the front brake lines together. As for the rear, ditch the load sensing valve and use an adjustable proportioning valve in the engine bay.

 

Works way better than anything else. I have done this both ways and documented the differences. But what the @#$% do I know? 

 

Some folks, who haven't done it both ways, feel that adjusting that POS load sensing valve is the cure-all. It isn't. 

You're leaving a TON of front braking effectiveness on the table by keeping the distro valve. 

 

You know, sometimes field testing and experience is more valuable than conjecture and demeaning someone's actual experience. Kinda like "fake news" in the Jeep technical realm.  

 

 

 

[kryptronic]

so help me out here. i am replacing both rear brake lines at this point cause both are rusted out. i wanna delete the load valve. so i plug the bottom or front port on the proportioning valve? 

if the line on the nose is lets say A, and the bottom is B, which do i plug and what do i do with the line? eliminate it? the line from the port that doesn't get plugged gets  the coupler in the rear and connects to the hard line that connects to the soft hose correct? 

so what i'm left with is the un plugged line running to the rear and connected to the coupler, that then gets connected to the hard line that connects to the soft line. everything else gets deleted right?????

ugh, i have a headache.

 

This thread kind of ran wild.  I just did this on my 91 Pioneer.  Here is what I did (removed rear load sensing valve, replaced MJ distro block with YJ prop valve):

 

(1) Remove the MJ distro block up front and put in a YJ prop valve.  You could use a prop valve from a YJ/XJ/ZJ.  Or you could do as some here do and plug a port on the MJ distro valve (no proportioning to the rear at all).  I am happy to report the YJ valve works perfectly, but I have not ran a load heavier than around 200 lb with it.

 

(2) The YJ/XJ/ZJ prop valves are plugged at the nose, so attach the hard line that ran to the front bottom port of the MJ distro block to the front bottom port of your new prop valve (if you replaced the MJ distro block).  Otherwise keep the bottom line plugged into the MJ distro block.

 

(3) Trace the hard line that was connected to the nose of the MJ distro valve to the rear of the truck, cutting it out as you go.  The two hard lines cross several times so the only way you'll know you are cutting out the right line is to follow it front to back and cut out 1-2 feet at a time.

 

(4) Remove the rear load sensing valve and T connector.  Couple the remaining hard line to the hard line that ran from the T connector to the drop hose.  At this point you will have a single hard line running from the bottom port of the prop valve or distro block up front to a coupler, to a shorter hard line to the drop hose.

 

(5) Bleed your brakes and test thoroughly.  Once I got full pressure to the rear brakes I blew a hard line on the rear axle, and then a wheel cylinder.  I had to replace both hard lines on the axle and both wheel cylinders in order to ensure the integrity of the braking system.

 

Good luck.

[cruiser54]

Here's what it boils down to.

 

There are a few ways to deal with the crappy brakes, the distro valve and the load sensing valve.

 

Some ways give better overall braking performance.

 

Not everyone has tried all of them.  Well maybe one person has..... 

[Jeep Driver]

All I know is I'm glad I had no idea what I was doing when I did mine. 

 

 

Braided SS is a great improvement also.

 

 

Can't wait to get my fronts done now.

[cruiser54]

All I know is I'm glad I had no idea what I was doing when I did mine. 

 

 

Braided SS is a great improvement also.

 

 

Can't wait to get my fronts done now.

I did the braided lines also to all of mine.

 

What are you gonna do with the fronts? 

[54bobby]

 

so help me out here. i am replacing both rear brake lines at this point cause both are rusted out. i wanna delete the load valve. so i plug the bottom or front port on the proportioning valve? 

if the line on the nose is lets say A, and the bottom is B, which do i plug and what do i do with the line? eliminate it? the line from the port that doesn't get plugged gets  the coupler in the rear and connects to the hard line that connects to the soft hose correct? 

so what i'm left with is the un plugged line running to the rear and connected to the coupler, that then gets connected to the hard line that connects to the soft line. everything else gets deleted right?????

ugh, i have a headache.

 

This thread kind of ran wild.  I just did this on my 91 Pioneer.  Here is what I did (removed rear load sensing valve, replaced MJ distro block with YJ prop valve):

 

(1) Remove the MJ distro block up front and put in a YJ prop valve.  You could use a prop valve from a YJ/XJ/ZJ.  Or you could do as some here do and plug a port on the MJ distro valve (no proportioning to the rear at all).  I am happy to report the YJ valve works perfectly, but I have not ran a load heavier than around 200 lb with it.

 

(2) The YJ/XJ/ZJ prop valves are plugged at the nose, so attach the hard line that ran to the front bottom port of the MJ distro block to the front bottom port of your new prop valve (if you replaced the MJ distro block).  Otherwise keep the bottom line plugged into the MJ distro block.

 

(3) Trace the hard line that was connected to the nose of the MJ distro valve to the rear of the truck, cutting it out as you go.  The two hard lines cross several times so the only way you'll know you are cutting out the right line is to follow it front to back and cut out 1-2 feet at a time.

 

(4) Remove the rear load sensing valve and T connector.  Couple the remaining hard line to the hard line that ran from the T connector to the drop hose.  At this point you will have a single hard line running from the bottom port of the prop valve or distro block up front to a coupler, to a shorter hard line to the drop hose.

 

(5) Bleed your brakes and test thoroughly.  Once I got full pressure to the rear brakes I blew a hard line on the rear axle, and then a wheel cylinder.  I had to replace both hard lines on the axle and both wheel cylinders in order to ensure the integrity of the braking system.

 

Good luck.

 

so i'm going from 2 lines running rearward to just 1 and that's coming from the bottom dist port, not the nose correct?

 

[Jeep Driver]

 

All I know is I'm glad I had no idea what I was doing when I did mine. 

 

 

Braided SS is a great improvement also.

 

 

Can't wait to get my fronts done now.

I did the braided lines also to all of mine.

 

What are you gonna do with the fronts? 

 

 

 

https://www.summitracing.com/parts/wil-140-12576d/overview/make/jeep/model/cherokee

 

 

There is nothing available anywhere for the WJ knuckle, I decided to go with the early knuckle and standard Jeep steering. 

 

I've had a couple of conversations with Wilwood, really wanted the 14" rotors, they referred me to TCE. TCE can make a kit for me for $2K. 

 

For now, I'm going with the standard package, once I have the parts and have it set up, I'll look to see what I can do with the mount and rotor combination. 

 

There is a 14" available, but no hat/rotor combo with the correct offset.

 

Pretty much have to use their SS lines........so............$ 1075 to my door, I'll live with that for now. 

 

 

I've decided on the Synergy steering package that I will order this week.........then another month for the Wilwood package. 

 

$600 here, $1000 there..........adds up..........since I'm poor............time.

[kryptronic]

so i'm going from 2 lines running rearward to just 1 and that's coming from the bottom dist port, not the nose correct?

 

Correct.