Stock proportioning valve plug

[kendawg73]

Ok so it's been a while since I've been on here, haven't been able to work on my Fox in a while, with finally getting a garage over a year ago (after wanting/needing one for 30+ years) and then doing a bunch of my stuff to my new to me daily 2012 Mustang I got just under 2 years ago, plus all the other car maint I have to do etc, the Fox has been on hold (8 year project now).

Well finally got to get back to laying hands on it, I had ran all new brake lines etc a while back, and just needed to put the front calibers on and lines... now I just have to install the booster and MC. So years ago I bought the rebuild kit for the Proportioning value (all the o-rings/seals) so yesterday I took it apart and cleaned it all out etc.. and got it back together, the only thing I'm kind of concerned about is the plug that has the rubber plug in the end, unfortunately the kit didn't include that. I'm just hoping it doesn't leak or anything. didn't look like it has but just a tiny bit of it poking out the hole in the inside of it. just hoping it didn't deteriorate since I don't know what it originally looked like on the inside of that plug.

the valve had a lot of black stuff etc in it (it's been removed from car for 6+ years, so I had to clean it out with my gun bore brushes etc. and looks like they don't sell any replacement one that I can find. I'm just hoping I don't have fluid leak from that plug, why is that there anyway?

I'm hoping to get the booster and mc in and the lines connected and then put fluid in it this week and bleed it... still going to be a while before it's on the road, still haven't even finished putting the intake, injector, accessories etc. on motor yet, Hard part is trying to figure out there stuff went/goes... since I basically striped car down, and replaced everything putting it back together with new oem or aftermarket upgrades etc.

 

[AeroCoupe]

You can get a used one from a salvage yard (www.car-part.com) for around $30.

 

[Mustang5L5]

Are you doing standard brakes as equipped from factory?


If changing the brakes, there is a plug that eliminates the small hole rubber plug. However, this plug is designed to be used with the prop valve removed and gutted out. Not sure it will work as a stock replacement part .

Mustang Brake Proportioning Valve Plug M-2450-A - LMR

Plug your factory proportioning valve with this 5.0 Resto direct fit Mustang Rear Disc Conversion Proportioning Valve Plug!

lmr.com

 

[AeroCoupe]

I saw a thread where a guy tried that and it locked up on the proportioning valve piston and tore the threads up on the body to the point he had to find a new one. I would think you could gut the proportioning valve side of the combination valve and then just install a manual proportioning valve like you were going to swap the rear to disc brakes. Never tried it but I would think it would work with drum brakes in the rear.

 

[kendawg73]

Are you doing standard brakes as equipped from factory?


If changing the brakes, there is a plug that eliminates the small hole rubber plug. However, this plug is designed to be used with the prop valve removed and gutted out. Not sure it will work as a stock replacement part .

Mustang Brake Proportioning Valve Plug M-2450-A - LMR

Plug your factory proportioning valve with this 5.0 Resto direct fit Mustang Rear Disc Conversion Proportioning Valve Plug!

lmr.com

Yeah I seen that plug, but I'm running the stock brakes (everything is new) but still drum in the back... I'm staying 4 lug since I got wheels already, but I would like to put disc on the rear eventually.

 

[kendawg73]

I saw a thread where a guy tried that and it locked up on the proportioning valve piston and tore the threads up on the body to the point he had to find a new one. I would think you could gut the proportioning valve side of the combination valve and then just install a manual proportioning valve like you were going to swap the rear to disc brakes. Never tried it but I would think it would work with drum brakes in the rear.

That's kind of what I'm wondering, if I gut it and buy that plug, and then install the ford manual valve that you use for the rear disk, even though I don't have rear disc yet, could I still run that and adjust it? that's the million dollar question. Hmmm and don't remember, do you have to change the MC?

 

[AeroCoupe]

If you were to go to rear disc brakes I would highly suggest you swap over to the 93 Cobra MC and booster but the booster is not 100% necessary. If you stay drum brakes then no change.

 

[Mustang5L5]

That's kind of what I'm wondering, if I gut it and buy that plug, and then install the ford manual valve that you use for the rear disk, even though I don't have rear disc yet, could I still run that and adjust it? that's the million dollar question. Hmmm and don't remember, do you have to change the MC?

You can gut it now and install the adjustable. You would then just adjust based on your drum brake combo.

There’s nothing that says you can only do the adjustable PV when going to different brakes.

In fact, if it gives you peace of mind to install the solid plug and adjustable valve now, go for it. One less step when disk brake swap time comes

 

[kendawg73]

You can gut it now and install the adjustable. You would then just adjust based on your drum brake combo.

There’s nothing that says you can only do the adjustable PV when going to different brakes.

In fact, if it gives you peace of mind to install the solid plug and adjustable valve now, go for it. One less step when disk brake swap time comes

well sounds like a plan for a path forward if I find that the old plug leaks, not sure why it has that rubber plug in it in the first place, and what would happend if you just removed it and tapped and plugged it (or if it's steal, just do a little tack weld and plug it.. Now to gut it, you just need to remove the stuff under that large cap and not the small one correct?

I see LMR has a rear disc brake kit for the 4-lug for 900.00+ it's looks like it comes with a MC and that ford adjustable control valve... but I really just want to roll with what I have for now and get the damn car back together and running before I think of doing that. this project has gone on for far too long.

I've been side lined from doing anything with this project in the last 2 years, feels like starting all over again... heck it's taking me so much time now to do stuff, I have to go find where I have the parts, looking in boxes etc, then figure out where/how they went on... looking at old pics I took before I took car apart or search the interwebs...

 

[Mustang5L5]

The valve in the rear is a shuttle valve. It is supposed to block flow if a line ruptures.

You just remove the valve in the front, and seal off the chamber making a little distribution block. You can do it whatever way you want once you pull the valve out.

 

[kendawg73]

The valve in the rear is a shuttle valve. It is supposed to block flow if a line ruptures.

You just remove the valve in the front, and seal off the chamber making a little distribution block. You can do it whatever way you want once you pull the valve out.

ok, but I was referring to that end plug, not sure why it has the rubber plug in the center of it in the first place, what's it's purpose of it, would seem like a like a bad idea... and now that this was old and kinda nasty inside when I cleaned it all and and install the new o-rings and seals, that's the only thing I would be afraid would leak (hopefully I will get to get this hook up and fluid in it and see) but I was wondering, with if you just plug that hole, would it cause issue... just has me curious...

but no biggie I guess, if it leaks there, I just buy the plug and gut it, and install the ford manual valve. Which that would just go in place of that fitting that joins the to brake lines together on the pass side firewall area correct.

 

[AeroCoupe]

That is where most install the manual proportioning valve. Just gut the stock proportioning valve, install the manual valve and bleed the brakes. Its small dollars and it will work no problem. Will keep you from dealing with brake fluid all over everything if the stock cap does not hold.

 

[kendawg73]

hmmm this popped up on some search, looks like MM makes a value eliminator kit - https://www.maximummotorsports.com/Assets/install/pdf/brakes/MMBAK-6.pdf, to just remove it.. so maybe I will just be better of getting this an the adjustable valve then, since all the lines are new SS ones, and no fluid has been put in yet, better to do it now they worry about brake fluid spilled.
now the question is, how should the valve be adjusted for the stock rear drums... hmmm I think when I was glancing at the instructions on the ford adjustable valve, think it's said in the middle was best, so I'm guessing for the rear drums I would want less flow (value closed more) for the drums, or am I thinking that backwards?

 

[Mustang5L5]

The adjustable valve really just adjust the knee-point. When you initially step on the pedal the front and rear all have the same pressure, but as brake pressure at the mc increases, the rear starts to see less pressure.

My thinking would be to start at lowest setting, and adjust in later knee-point as you get more confidence in brake performance. You want to account for worst situation you will find yourself in. If you drive in the rain, you might want to do some testing, but err on the side of a lower knee-point to the rear brakes. The fronts do most of the work

 

[kendawg73]

The adjustable valve really just adjust the knee-point. When you initially step on the pedal the front and rear all have the same pressure, but as brake pressure at the mc increases, the rear starts to see less pressure.

My thinking would be to start at lowest setting, and adjust in later knee-point as you get more confidence in brake performance. You want to account for worst situation you will find yourself in. If you drive in the rain, you might want to do some testing, but err on the side of a lower knee-point to the rear brakes. The fronts do most of the work

ok, sounds good... unless I get caught in a pop-up rain, this car will never be driving in the rain, just a takeout the garage new weather cruise car.

also, I see MM also sells an adjustable valve made by Wildood, I'm guess that would be better or just as good as the Ford one? since I'm going to be getting that eliminator kit from MM might as well get that from them too I'm thinking.

Just wish I knew this all ahead of time before I spent a couple hours taking apart the old valve and cleaning it up and replacing the seals etc.... oh well

 

[Mustang5L5]

also, I see MM also sells an adjustable valve made by Wildood, I'm guess that would be better or just as good as the Ford one? since I'm going to be getting that eliminator kit from MM might as well get that from them too I'm thinking.

The Ford and Wilwood valve are the same. Just a matter of what logo you prefer on it. Get the cheapest you can find.

 

[AeroCoupe]

Bear also makes one so another cool logo.

 

[Mustang5L5]

Summit also has their own branded version too.



Also, the non-ford ones do have different connections available. The outlets on the valve itself are 1/8 npt but the adapter fittings supplied should be 3/8-24 for fox body use if you are installing it at the firewall union