What is it ?

[AMC86Kid]

ok guys take a look at this pic 

and hopefully you can tell me what it is 

its under the bed on the driver side rear 

i was wondering what does it do and if i need it or can i remove it 

it has like a swinging bar that swings from left to right 

[Big Dan]

Its the brake proportioning valve, its disconnected.

[Eagle]

That's the load sensing (or height sensing) proportioning valve for the rear brakes. The purpose is to reduce pressure to the rear brakes when the truck isn't loaded, so the rear brakes don't lock up too soon and cause you to spin out. As the bed is loaded, the bed drops relative to the axle, causing the arm to move and increase the amount of pressure to the rear brakes.

 

However, that swinging arm is supposed to be horizontal, and there should be a connector link to a ball stud on the differential housing. Yours appears to have been disconnected by some previous owner.

 

There are photos in other threads here that show how it's supposed to look. Do some poking around in this discussion area and the D.I.Y. area, or maybe someone who remembers where to find the photos will jump in with a link.

[AMC86Kid]

when you say horizontal do you mean its suppose to swing from front bumper to rear bumper ?

 

 

ok i will look around to see what its suppose to look like

hopefully some one will post a pic of how it should look

so basically you recommend that i keep in on there and don't remove it 

[Eagle]

No, it's swinging across the vehicle centerline, correct? You wrote that it swings left to right. The basic position for it should be swung to the right (passenger side) and up, so the arm is parallel to the ground.

[Eagle]

Here ya go:

 

 

This doesn't show the axle end, but this is what the arm should look like when connected.

 

Even better:

 

http://comancheclub.com/topic/45839-mj-height-sensing-brake-proportioning-valve-adjustment-procedure/

[AMC86Kid]

oh ok so it swings from the top of the driver side rear tire down to the rear axle ok i get it 

but where does the other end of that metal rope connect to ?

[Eagle]

oh ok so it swings from the top of the driver side rear tire down to the rear axle ok i get it 

but where does the other end of that metal rope connect to ?

 

Did you click the link I provided?

 

That tire in the photo is not the driver's side tire, it's the spare.

[DirtyComanche]

It's a rod.

 

It goes to the diff cover area.  There's a stud for it there.

 

95% of ones I encounter have been disabled either intentionally or not.

[AMC86Kid]

ok i clicked on the link and i see what your saying it regulates the brakes so they will be stronger in the back if a heavy load is applied to the bed 

so if i remove it then when my bed is carrying a heavy load i will not get as much breaking power as with it on 

[Eagle]

so if i remove it then when my bed is carrying a heavy load i will not get as much breaking power as with it on

 

No.

 

Go to the D.I.Y. area of the forum and you'll find an article on how to remove it. It's not as simple as it seems, because it involves the total removal of one of the two brake lines from the front to the rear -- and many people remove the wrong one before they figure out the mistake.

 

If you remove it, you will always have FULL brake power to the rear wheels. That might sound like a good thing, but the back of a pickup is pretty light when there's no load, so on snow or ice, or in a panic stop, or even in the rain, the rear wheels will lock up before the fronts. That causes spin-outs. That's why the factory put that thing in there. You would be better advised to fix up a rod and connect it so it functions properly.

[AMC86Kid]

oh ok so i will try to hook it up and take a pic 

then maybe you guys can tell me if it looks like i hooked it up correctly 

[HOrnbrod]

 

http://comancheclub.com/topic/16955-adjustable-mj-load-sensing-valve/

[AMC86Kid]

awww i see ok i will try to make a bar and connect that swinging piece of metal to the clip bracket on the axle thanks 

[dasbulliwagen]

Another thing you can do if you can't get the rod or the bracket is gone from the diff is use a piece of wire or a zip tie to hang the swinging arm in the 2-3 oclock position from above. This will give you some use of your rear brakes back without going through the trouble of finding the parts you need to fix it properly.

[AMC86Kid]

ok thanks 

[desbennett004]

 

http://comancheclub.com/topic/16955-adjustable-mj-load-sensing-valve/

On a side note, is that the factory rear sway bar in that picture? My MJ didn't come with one, I guess it was removed by the PO?

 

Sent from my SM-N900W8 using Tapatalk

[AMC86Kid]

idk but it sure don't look factory

with it being all shinny and black 

[HOrnbrod]

MJs never had a factory sway bar. I did it myself HERE and it's a very worthwhile mod for a street rig.

 

Shortbed model HERE
 

Unfortunately the guy that posted this pulled his pics.

[AMC86Kid]

does the sway bar make your back axle stronger ?

[Dzimm]

No it helps minimize body roll when turning or driving across a slope. It also limits the flex of vehicles so most offroad rigs don't have them. Does nothing as far as strength to the axle.

 

Side note, Google is your friend as is the search box here.

[Eagle]

idk but it sure don't look factory

with it being all shinny and black 

 

Everything about Hornbrod's MJ is either shiny or black. He's like that -- a thoroughly despicable person. :thumbsup:

[AMC86Kid]

good to know thanks 

[RustyRodder]

Well this was a nice topic- after reading, I went to look if mine was still hooked up!

[AMC86Kid]

well is it still hooked up ?