Swapping A Proportional Valve

[Burton58]

could be the worst deal ever

[customcreationsllc]

I don't think the proportioning valve is even built into the combination valve on the XJ I think the proportioning is in the master.

The combo valve only has a residual pressure valve and a shuttle valve to turn the light on when you loose a brake line.

Can you post a picture?

adjustable external prop valves are only like $30 and easy to install install it on whatever brakes lock up first they only reduce pressure not make more pressure.

[ct67_72]

I don't think the proportioning valve is even built into the combination valve on the XJ I think the proportioning is in the master.

I think you might be right. Ive just started to look into it more since I changed to a dodge van master cylinder on mine. Used to lock up the rear pretty early with the XJ master, and now it seems to stop pretty even with the dodge.

[Hudson]

I don't think the proportioning valve is even built into the combination valve on the XJ I think the proportioning is in the master.

The combo valve only has a residual pressure valve and a shuttle valve to turn the light on when you loose a brake line.

Can you post a picture?

adjustable external prop valves are only like $30 and easy to install install it on whatever brakes lock up first they only reduce pressure not make more pressure.

You want a picture of underneath my hood where my master and prop valve currently are in my XJ or what? I might have one lingering on my phone that i can post. Give me a second to check, if not i'll post a picture when i get home.

EDIT: No pictures of under the hood on the Jeep. I'll take one when i get home at around 4.

[justtorchit]

I don't think the proportioning valve is even built into the combination valve on the XJ I think the proportioning is in the master.

The combo valve only has a residual pressure valve and a shuttle valve to turn the light on when you loose a brake line.

Can you post a picture?

adjustable external prop valves are only like $30 and easy to install install it on whatever brakes lock up first they only reduce pressure not make more pressure.

correct..... but everyone calls the combo valve the proportioning valve.
just easier to say so everyone knows what your talking about....

[Hudson]

correct..... but everyone calls the combo valve the proportioning valve.
just easier to say so everyone knows what your talking about....

So you're basically saying i shouldn't even touch any of that setup unless my master is actually shot and needs replacement?

[justtorchit]

So you're basically saying i shouldn't even touch any of that setup unless my master is actually shot and needs replacement?

yes, i have been saying.... and ill say it AGAIN

NO NEED TO TOUCH THE COMBO VALVE (aka the non proportioning/residual/shuttle valve )

EVEN IF YOUR MASTER IS BAD, EVERYONE IN THIS THREAD HAS STATED THEY DIDNT SWAP THE VALVES!!!!!!


now replace your pads
pop the o ring out of the residual valve
bleed the shit out of your brakes
and see if its good to go


sorry but i feel like im beating a dead horse.

[justtorchit]

READ THIS

[Hudson]

yes, i have been saying.... and ill say it AGAIN

NO NEED TO TOUCH THE COMBO VALVE (aka the non proportioning/residual/shuttle valve )

EVEN IF YOUR MASTER IS BAD, EVERYONE IN THIS THREAD HAS STATED THEY DIDNT SWAP THE VALVES!!!!!!


now replace your pads
pop the o ring out of the residual valve
bleed the shit out of your brakes
and see if its good to go


sorry but i feel like im beating a dead horse.

I'm half retarded so it's all good.

I will do exactly that and report back.

Reading that now.

[justtorchit]

no problem lolololol. just report back after you do that. we will go from there.



but back to the discussion, There is alot of shitty information out on how the valves work.... and i want to know whats true and whats not.

the removing the oring trick..... lots of misleading info out there saying it makes it 50/50. but we r saying that it is a residual valve and just keeping pressure in the rear brake lines. How exactly does this work? by looking at this picture:

one would think that the section on the front where the o ring comes out would be the proportioning section...... WHAT IS THIS O RING DOING? How does its work? I dont have a combo valve sitting infront of me and im not running out to take mine apart to understand it.

[justtorchit]

looking at this picture fluid flows past the differential piston (shuttle valve), then flows into the proprtioing valve (which resembles the front section of a xj combo valve). correct? so does the xj combo valve indeed include a proportioning valve? where is the o ring located?

[customcreationsllc]

I'd need better pictures or parts in hand.
What I remember is that it is only a check valve.
The o-ring is a lip seal so only prevents fluid from coming from the wheel cylinders back to the master. and lets the fluid from the master flow freely to the wheel cylinder.

But it has been a while.

I think this guy has the lip seal back words, it doesn't make sense that way but I would like to see an XJ cross section.
http://www.lunghd.com/Tech_Articles/..._Valve_Mod.htm

Like I said it has been a while.
Either way I would remove the ring and install an adjustable prop valve as needed they are only $30

[justtorchit]

I'd need better pictures or parts in hand.
What I remember is that it is only a check valve.
The o-ring is a lip seal so only prevents fluid from coming from the wheel cylinders back to the master. and lets the fluid from the master flow freely to the wheel cylinder.

But it has been a while.

I think this guy has the lip seal back words, it doesn't make sense that way but I would like to see an XJ cross section.
http://www.lunghd.com/Tech_Articles/..._Valve_Mod.htm

Like I said it has been a while.
Either way I would remove the ring and install an adjustable prop valve as needed they are only $30

Yes, i was looking around and finally found a decent photo of it... i do believe this is just a check valve and the oring is just the seal.... so basically the piston and spring can be removed aswell and it would do the same. i might have one laying around the garage to see in person.

and yes i do agree with the the adjustable prop valve... did that with rear disc swap on a yota.

[customcreationsllc]

Yes, i was looking around and finally found a decent photo of it... i do believe this is just a check valve and the oring is just the seal.... so basically the piston and spring can be removed aswell and it would do the same. i might have one laying around the garage to see in person.

and yes i do agree with the the adjustable prop valve... did that with rear disc swap on a yota.

You cannot just remove the piston and spring I tried that there is another seal on the shaft if it is not in there brake fluid just comes out the hole.

[Hudson]

Well just put new pads in the rear and bled the system. (Did not remove any o-ring or touch the prop valve/combo/whatever you want to call it.)

Brakes were really firm when the engine was off, but the second i started it up the brakes went back to where they originally where. (I think this means my brake booster is working correctly?)

Possibly my master going out?