So this summer I have to redo all the brake lines on my GL. So I'm just gonna rip everything in the back of the car out and start over, because at this point that's the best option. But what should I do about the stupid proportioning valve? It's a ball of rust, I'm never getting the old lines out of it, and don't even want it back in the system.

 

I've swapped to rear disc brakes, so do I even need it anymore? Or can I just get a splitter and run one line to each back wheel and call it good.

Forgot the year, it's an 89, and it's a sedan. if that actually matters.

I've swapped to rear disc brakes, so do I even need it anymore? Or can I just get a splitter and run one line to each back wheel and call it good.

 

You need it even more with the discs. Supposedly......to keep the rears from locking too easily.

 

These are diagonal setups......so each circuit feeds one front, and one rear wheel.  The proportioning valve balances the force to the rears against eachother.

 

And no you can't just get a splitter......it's 2 seperate hydraulic circuits.......2 lines from the master.......2 lines back to the wheels.....

 

If you want to get rid of it.......you need to just bypass it.......hook the lines straight toghether after determining which ones are for which side.

Edited April 9, 201411 yr by Gloyale

What he said... ^^^^ 

 

If you are going to modify the carefully designed and balanced factory braking system then you need to know exactly what you are doing and why. Otherwise, you run the risk of spinning out of control during a rainy night panic stop on the freeway and possibly hurting someone!!!

Edited April 9, 201411 yr by Crazyeights

Ugh, ok. So where do I get a new valve?

I do believe non-abs EJ cars have one mounted in the engine bay.......different look but works the same.

Nice!!! thanks. Should be nice and clean being in the engine bay. Or at least, not a total pile of crust.

Seems pointless to install a Proportioning valve from the wrong car.

 

How would it know how to Proportion properly?

How would it know how to Proportion properly?

 

Magic!

Seems pointless to install a Proportioning valve from the wrong car.

 

How would it know how to Proportion properly?

 

It's just a balancer.  Could be used from anything.

 

It's not like a variable one in the back of toyota pickups for when carrying load.(those are not diagonal systems)

It's just a balancer.  Could be used from anything.

 

It's not like a variable one in the back of toyota pickups for when carrying load.(those are not diagonal systems)

 

But the proper balance depends on weight distribution,total weight,what brakes you have etc.

But the proper balance depends on weight distribution,total weight,what brakes you have etc.

 

It balances pressure between the 2 circuits of the braking system.  Doesn't care how big/small/heavy the car is.  It just keep the 2 circuits equal

 

It could be use on any vehichle with even a remotely similar capacity system.

Not all EJ cars have a diagonal split either. They went to front/rear at some point.

 

I can look under a wreck here for you & post one. Our's might be very dusty, but never rusty.

Not all EJ cars have a diagonal split either. They went to front/rear at some point.

Nah.....they are all diagonal.

 

Some got rid of hillholder.....but they are are dual diagonal here for sure up through 3rd gen I know.......I guess I can't be positive past that.

It balances pressure between the 2 circuits of the braking system.  Doesn't care how big/small/heavy the car is.  It just keep the 2 circuits equal

 

It could be use on any vehichle with even a remotely similar capacity system.

No, it changes the pressure to the rear brakes once it's internal knee point is reached. The pressure in the two circuits is the same because the master cylinder bore is the same.

 

This knee point setting depends on a lot of car/brake parameters. I use a Wilwood adjustable valve on my van because I replaced the front and rear brakes with ones from a different car. It's not trivial to find the optimal/safest adjustment.