Proportion Valve Leaking

[Jc.av8r]

Any tips on how to stop this leak?? Noticed it recently but it's obviously been at work for a while. All the paint on my frame around this area is bubbled and peeling off.

Can I just disconnect the lines, clean it up and re-install? Should I replace with a new one? I can only assume this is the original proportion valve that either came with my front disc brake kit (2014) or from factory(?).

Seems like a common problem.

 

[DirtDonk]

Would likely have come with the kit.
Ford didn’t use that style on our vintage vehicles that I’m aware of. Certainly not before 76 when the disc brakes became available, and those were cast blocks rather than machined and almost never leaked.

I would unscrew the offending valve, check for debris, check the condition of the sealing surface and the gasket (probably metal) and reinstall.
Make sure it’s good and tight, but remember it’s brass, so probably not as tight as you might usually put some thing on a bronco.

That’s just to see if you get lucky and stop the leak without having to replace any parts.
You could certainly get a whole new unit, but you can also buy new valves and gaskets as far as I’m aware.

 

[Jc.av8r]

Would likely have come with the kit.
Ford didn’t use that style on our vintage vehicles that I’m aware of. Certainly not before 76 when the disc brakes became available, and those were cast blocks rather than machined and almost never leaked.

I would unscrew the offending valve, check for debris, check the condition of the sealing surface and the gasket (probably metal) and reinstall.
Make sure it’s good and tight, but remember it’s brass, so probably not as tight as you might usually put some thing on a bronco.

That’s just to see if you get lucky and stop the leak without having to replace any parts.
You could certainly get a whole new unit, but you can also buy new valves and gaskets as far as I’m aware.

Thanks, I'll try that before buying a new valve. My master cylinder and hard lines don't look wonderful, but I'll try to troubleshoot first.

 

[69_Sport]

It looks like you may have the same problem I faced. Try this cheap fix from Summitt:

https://classicbroncos.com/forums/t...p-valve-rebuild-info-help.293896/post-3197290

 

[Jc.av8r]

It looks like you may have the same problem I faced. Try this cheap fix from Summitt:

https://classicbroncos.com/forums/t...p-valve-rebuild-info-help.293896/post-3197290

Thanks, unfortunately Summit says the part is no longer available.

I’ll reach out to them to try and confirm if they have it under a different #.

https://www.summitracing.com/parts/CLP-PVMVK-T

 

[Jc.av8r]

Would this be the same thing?? New part # or not compatible?

https://www.summitracing.com/parts/clp-pvmvk-d

 

[Qumanchew]

Good luck! I replaced mine twice within a few thousand miles. Quality parts are hard to come by anymore. I fixed the problem by replacing it with a simple adjustable valve.

 

[69_Sport]

Would this be the same thing?? New part # or not compatible?

https://www.summitracing.com/parts/clp-pvmvk-d

Looks like the same thing.

 

[DirtDonk]

A couple of years ago I was very surprised to see Wilwood come out with a proportioning valve/combination valve that looks just like all these others that are so problematic.
I don’t know if they make it themselves, or if it’s made by someone else, but I would sure hope that they would only put their name on it if it was of higher quality.

 

[Qumanchew]

Since you brought up Wilwood it reminded me. When I was looking for an adjustable valve I was on Summit. They had the Wilwood brand but also a Summit one that looked identical but about $10 cheaper. Bought the Summit one. When I got it I peeled off the Summit sticker to paint it and it was an actual wilwood brand.

 

[DirtDonk]

That’s funny. Not that it’s uncommon, or not well known that big companies like Summit, or even small ones do this with a lot of their vendors.
Just that usually they go to a little greater extent with their vendors to cover up the origins.
A little decal over the original logo seems pretty simple for a real private label product.

 

[Jc.av8r]

I ordered that part from Summit, hopefully that will fix everything and seal it up!

For those that have changed that part before, can you tell me if I need to drain/bleed the system before I take it off or can I just back out the leaky part and screw in the new one without pouring fluid everywhere?

I need to bleed the system anyways but just want to know what to expect.

Thanks

 

[DirtDonk]

That valve is in direct contact with the circuit for the front brakes. So I’m guessing that even if it doesn’t actually flow out, it could dribble out and continue to do so if you don’t put a finger over the hole pretty quickly.
It’s only halfway down to the bottom though, so it won’t have the full weight of fluid pushing on it.
Should be a slower dribble than cracking a bleeder then, other than the fact that it’s four times the size of a bleeder nipple!

In theory, you should only have to bleed the front brakes after that to make sure that you got all the air out.

I haven’t actually done that though, so I’m just speaking out of my hat.
Plenty of members have messed with it so hopefully they’ll have their experiences to relate.

 

[Jc.av8r]

That valve is in direct contact with the circuit for the front brakes. So I’m guessing that even if it doesn’t actually flow out, it could dribble out and continue to do so if you don’t put a finger over the hole pretty quickly.
It’s only halfway down to the bottom though, so it won’t have the full weight of fluid pushing on it.
Should be a slower dribble than cracking a bleeder then, other than the fact that it’s four times the size of a bleeder nipple!

In theory, you should only have to bleed the front brakes after that to make sure that you got all the air out.

I haven’t actually done that though, so I’m just speaking out of my hat.
Plenty of members have messed with it so hopefully they’ll have their experiences to relate.

Thanks for that.

Either way the small side of my brake booster has really dark fluid. It hasn't been changed in a very long time.

 

[TAC71]

We have used those type of proportioning valves in the past. NEVER again. We build custom cars and have had so many leak that we won't use them anymore.
Absolute offshore garbage.

 

[badandy73]

OP, save yourself the headache and just replace it with one of these:

https://www.wildhorses4x4.com/product/19012/Bronco-Proportioning-Valve

https://www.summitracing.com/parts/wil-260-11179

That way you're covered if you decide to do any future brake upgrades/ changes in the future. I've been running the wilwood unit since I installed it with my hydroboost setup 8 years ago and it's still as dry as the day I put it in. Bolts right to the same bracket you already have.

 

[Jc.av8r]

OP, save yourself the headache and just replace it with one of these:

https://www.wildhorses4x4.com/product/19012/Bronco-Proportioning-Valve

https://www.summitracing.com/parts/wil-260-11179

That way you're covered if you decide to do any future brake upgrades/ changes in the future. I've been running the wilwood unit since I installed it with my hydroboost setup 8 years ago and it's still as dry as the day I put it in. Bolts right to the same bracket you already have.

Thanks, I do want to upgrade to the hydro boost kit, but just spent too much on her lately so this small part will have to do for now!

 

[Jc.av8r]

This was helpful.

 

[bronco italiano]

Try musclecarresearch. They make rebuild kits for proportioning valves. Very good stuff