Proportioning valve

[Muswagon]

My 71 duster has a leaky valve where the front main brake line goes in at the top. I’m going to double check that it’s not a flare issue with the brake line itself.

It’s a disc/drum valve. I don’t see much available for Mopar valves, can a GM PV2 be used in its place?

 

[Professor Fate]

Is this a new replacement valve, or the factory stocker?
New valves are commonly available from many sources; such as Inline Tubes, Fine Lines, Doctor Diff, Mancini, Classic Industries, just to name a few...
Don't know why on earth you'd want to try to run a GM valve.

 

[Muswagon]

It’s the stock valve that was there for the Kelsey Hayes setup that is now gone.

I’m in Canada so a valve is a week away at best, but I can get pv2 valve today at speed shop locally. Plan was to shake the car down and maybe go to a car show Sunday.


So, as per original question, will it work? I assume they are the same pv2 style for all disc/drum?

 

[mvh]

First, let's clarify what you are looking for. The brass block with two inputs from the master cylinder and 3 exits to the brake lines (2 front and 1 rear) is not a PV — it is a safety switch & distribution block. The Kelsey-Hays disc brake systems had a second brass block in the line to the rear axle, which was the proportioning valve.

The 73-up single-piston disc brake systems changed this and used a single block for both functions. This seems to confuse a lot of people, but the point is that these "distribution blocks" are not interchangeable if you want proper function.

I don't know which system GM cars used, but it would be a good idea to find out before jumping in.

 

[Muswagon]

That is where I get a bit confused.... I had read that it was in 71 they went to an actual dist/prop valve singular instead of the two piece (dist block/safety and the prop valve) you are talking about.

My car still had all original lines, or at least they looked original bend quality and enough crust to lead me to believe that, and was nothing else in the rear line. It was plumbed directly into the big block without the secondary smaller prop valve.

 

[Inertia]

My 71 duster has a leaky valve where the front main brake line goes in at the top. I’m going to double check that it’s not a flare issue with the brake line itself.

It’s a disc/drum valve. I don’t see much available for Mopar valves, can a GM PV2 be used in its place?

I think you'll find the GM valve doesn't self-center .
You will likely have to manually bleed to turn off the in-balance lite.
A pain if you plan on using line-loc .
Good luck .

 

[Muswagon]

Based on how Mancini's prop valve page explains it, mine is a combination valve, and the other one is a dist block with a secondary valve

This is what I have

This is what they explain to be the two parter... But I am just going off how they explain it, don't rip my head off

 

[CFD244]

That is where I get a bit confused.... I had read that it was in 71 they went to an actual dist/prop valve singular instead of the two piece (dist block/safety and the prop valve) you are talking about.

My car still had all original lines, or at least they looked original bend quality and enough crust to lead me to believe that, and was nothing else in the rear line. It was plumbed directly into the big block without the secondary smaller prop valve.

You are correct. The 1971 uses the full 1 piece proportioning valve with the OEM Kelsey Hayes set up. It can either be a Kelsey Hayes unit, or a weatherhead (sp?) unit. Not sure when the changeover from 2 piece to one piece occurred. It could very well be early '71 vs late '71.

Maybe @Oldmanmopar can give us some insight as to when the change occurred.

 

[Muswagon]

Appreciate the help all.. I think I fixed it. The right stuff line that goes from the master to front port on prop valve had a bad flare… I’ve noticed that with the last few kits from them, the flares are garbage. I cut off a tiny bit and reflared and it seems to be sealing. I should have triple checked the lines before I installed them