Rear brake drum performance

[fgross2006]

Well here I go again. I'm just a glutton for punishment. After corresponding with the kit seller he offered to sell me a new brass piston with the brass sleeve, all the o rings for that side of the valve and a retainer cap to put on the end of the spring.

I'm gonna take another shot at this since only one side has to be corrected. And since the brake line have just been removed and that i treated the threads with a dash of never seize, they will come out easy so I can do this myself. I'll get my son to help me re bleed them when I put it back in. This has to be correctable.

My only question is should I get a new brake fluid sensor from NPD just to have a new one? Just in case mine does have damage from being heated with a torch. Also, is this even gonna work in an 84? Its identical to mine except mine is red. But the listing says its for 67-69 Stangs.

https://www.npdlink.com/product/warn...%3D0%26year%3D

[qikgts]

Might be worth asking Musclecar Research if they have the switches too or at least can tell you what will work in there. I don't think yours is bad though. Just do a continuity test.

[fgross2006]

Might be worth asking Musclecar Research if they have the switches too or at least can tell you what will work in there. I don't think yours is bad though. Just do a continuity test.

a continuity test will tell me if its still a good sensor, but I'm concerned with why it allowed brake fluid to pass through the top.

[85GTGuy]

A bad o-ring would allow brake fluid to make it's way to that center section, wouldn't it?

[qikgts]

I don't think the switch is meant to be sealed. Remember, it's installed into a what should be a dry port.

[fgross2006]

after getting the same issue of leaking through the sensor after yet another rebuild, I was considering getting an aftermarket proportion valve from Amazon or NPD.

Then I saw this guys link to a short youtube vid that shows the brand new ones have the same tendency to leak through the port the sensor goes to. I hate to waste all the time to pull and replace again and still have the same issue.

[Bentley]

I am going through what you did right now... All of my lines came off and the only real problem I am having is getting the same piston out that you had a hard time with...
Waiting now for some fittings to cap off ports to try and use air pressure to push it out if that doesn't work I found the adapter at Speedway to screw in and attach a grease gun to..
Someone said pipe threads here and these are NOT NPT threads, they are UTS threads.... Making this more of a pain..
My valve caught me off guard as I thought it was in good shape, but it was plugged with dried hard brake fluid..... Seems to me the area where the stuck piston is is plugged as I cannot get air to blow through it.....

the part number on my OEM P valve is EOZC-2B328-AA... These are unobtainable from what I have found and NOBODY is reproducing them or seems to be interested in doing so... The " service valve" number, for this P valve, is EOZZ-2B257-A which when googled brings up a DOZZ-2B257-A... Summit has these for sale, they show they fit a 70 mustang, but the picture is EXACTLY what my EOZC-2B328-AA looks like.....
I have been tempted to order one, but I get tired of parts that don't work..... Its a $108 dollars.....
Any updates on your car??

[85GTGuy]

....but it was plugged with dried hard brake fluid..... Seems to me the area where the stuck piston is is plugged as I cannot get air to blow through it.....

No idea if it would do anything, but maybe soak it in a brake fluid bath for a few days. Might help loosen/soften/dissolve the dried crud.

Glad to see you made it back.

[Bentley]

No idea if it would do anything, but maybe soak it in a brake fluid bath for a few days. Might help loosen/soften/dissolve the dried crud.

Glad to see you made it back.

Thanks for the welcome... Thats not a bad Idea.. I did soak it in some Transmission flluid and when I turn the piston it seems harder now.. I think the seals swelled up, making it worse, so I am hesitant to soak it again..
Bit of a moot point, if I do not find the correct fitting ( went to 3 auto parts stores today) there is no way to " put it under pressure" to press it out.. The fitting I had ordered 5/8-24, did not work, it was a hair too big...... Nobody can figure out what size or what threads these are..

Reminds me of looking for the exhaust manifold plugs when we removed our smog pumps " back in the day" ... Some weirdo threads on those too.....

[fgross2006]

Reviving this thread;

I never solved my proportion valve issue last summer. I capped the port the brake light sensor goes in and it holds pressure so I can drive and have decent brakes, but since there's brake fluid leaking internally to the brake light sensor, it means the proportion valve cannot "proportion" if I'm explaining it correctly.

I now have equal brake pressure front and rear and lock up at high speed causes fishtail. At highway speed, under the right conditions the car could flip and that makes me wary driving fast or on the parkway.

I did get one of these from an amazon seller last year. Although mine didn't come with a bracket.

https://www.amazon.com/product-revie...ews-filter-bar

But if you read a lot of reviews on these aftermarket brake valves, everybody says the bracket is backwards and some people say they still get leaks out of the brake light sensor with these brand new valves.

My original seems stamped into place. Not sure if I could remove it without destroying the original valve. I thought of buying another one that comes with the bracket but what I realized looking at pics others posted in Amazon is that when they say the bracket is backwards, it's not on the wrong side as in driver fender or passenger fender mount. Its mounting studs are towards the front when they should be towards the back. That would require replacing or repairing all 4 mounting brake lines because the valve would mount about 3 inches shifted.

Assuming I can either get my old bracket off and use it, or have a local machine shop make me a bracket, if I still get fluid leaking from the brake light sensor with the replacement part then its all for nothing. I decided that I will try this part 1 time, if it fails me I'm going to get a manual proportion valve from LMR and be done with this headache.

The thing about that is, I've read that when installing a rear manual proportion valve, the original proportion valve remains in place but the rear piston removed. I would assume that would render the brake light sensor useless once again am I correct? If I pull one of the pistons out, nothing will prevent brake fluid from flowing to the center and getting in the brake light sensor.

Any suggestions before I dive back into a massive headache again?

[bob85gt]

my light sensor was leaking a long time ago. capped it off and installed maximum brake proportioning valve. followed there instructions. light sensor does not work. and i was on there site and see they still sell it and the kit. https://www.maximummotorsports.com/B...alve-C145.aspx. i do not do any high speed driving , but is it seems to have good balance to me.

[fgross2006]

Has anybody tried this aftermarket proportion valve from NPD?

It retains the brake light switch but the mounting holes look spaced for a Chevy.


https://www.npdlink.com/product/valv.../214018/150106

[OldFox]

I never solved my proportion valve issue last summer.

That's because in order for the rebuild kit to work properly as designed (as with any rebuild kit for anything) the core components and bores need to be in near perfect condition, and most are not due to 40 years of internal corrosion from water contaminated brake fluid (i.e. not being changed regularly and brake fluid is hygroscopic)

I capped the port the brake light sensor goes in and it holds pressure so I can drive and have decent brakes, but since there's brake fluid leaking internally to the brake light sensor, it means the proportion valve cannot "proportion" if I'm explaining it correctly.

I now have equal brake pressure front and rear and lock up at high speed causes fishtail. At highway speed, under the right conditions the car could flip and that makes me wary driving fast or on the parkway.

The upper chamber shuttle valve distribution is leaking past the seals internally and not working correctly, along with the lower level proportioning valve for the rear brakes affected, so yes that is bad.

But if you read a lot of reviews on these aftermarket brake valves, everybody says the bracket is backwards and some people say they still get leaks out of the brake light sensor with these brand new valves.

That's because most of those aftermarket valves are junk and I wouldn't put one on my car.

Any suggestions before I dive back into a massive headache again?

Yes, you buy a brand new factory Ford valve (new old stock) for a 1980-1986 V8 or 4cylinder up to 1993 (normally cost $300 to $400). They can be difficult to find, so if you can't find one of those you can use a Tbird/Cougar value ($200 range) which is nearly identical, but has a slightly different slope angle and rear pressure release, so in layman's terms the Tbird/Cougar proportioning is designed for the bigger/heavier cars .43slope/400psi (comes in later) than the Mustang/Capri cars depending on engines and options, below is chart...

'80 Mustang/Capri, Fairmont/Zephyr 3.3L, 4.2L, 2.3L Turbo = 300 psi / .28 slope
'80 Mustang/Capri 2.3L = 400 psi / .28 slope
'81 Mustang/Capri 2 way alum = 300 psi / .28 slope
'84 to '86 SVO = 200 psi split / .28 slope
'87 Mustang (All engines) = 300 psi split / .28 slope
'87 to '93 Fox (Unknown Engine) = 300 psi split / .28 slope

T-bird, XR-7 3 way alum = 400 psi / .43 slope
F/Z (sedan) 2 way alum = 300 psi / .43 slope
F/Z (sta. wagon) 2 way alum = 400 psi / .43 slope
Mustang/capri 2.3L 2 way alum = 400 psi / .28 slope
Mustang/Capri 2 way alum = 300 psi / .28 slope
Granada/Cougar 2 way alum = 300 psi / .43 slope

In a nutshell, the Tbird/Cougar valve would be 1000 times better than what you have now, and there are 2 currently for sale that I know of...

https://www.ebay.com/itm/126527021810

https://www.ebay.com/itm/186436554969

There is no guarantee that 40 year old NOS parts are going to be good, but in most cases they are and worth rolling the dice considering the very limited OEM options you have.

[fgross2006]

Thats a lot of good info OldFox, but I still have the aftermarket proportion valve I got on Amazon last summer and I found an ebay seller with the bracket so I plan to try to use it. If it leaks from the brake light sensor as well, I'm moving on to the NPD universal proportion valve. It has the brake light sensor which the Wildwood and Ford manual proportion valves do not. The only thing I don't like is the hole pattern is for a Chevy PV even though NPD lists the part for Foxbody Mustangs. I'm sure the valve will function, but I'd have to make a bracket to use it.

I have a new brake problem. I took my Mustang for a run on the parkway to go to a doctor appointment about 25 miles from home. Got there OK, on the way back I started to feel the brake pedal getting spongy and low. It was a tedious drive home with poor brake power. When I got close to home I tested the brake hard and found there no lockup at all. Just a slow down.

I checked all 4 wheels for leakage and its bone dry. I popped the master cylinder cover and its full to the top. I did replace the master last year but it's possible its gone bad already. Something is sucking air in and not leaking out so the MC is my best guess. I'm gonna swap out the MC and the PV hopefully today. I just cant find an auto parts store with a master cylinder bleed kit so I may have to make one with hardware store parts, if not Ill have to wait a few days till I can get a Dorman kit.

[fgross2006]

So here's how it ended up. So far so good. I pulled the master cylinder and installed the new aftermarket proportion valve. I had to make a small adaptor to connect the front brake line feed to the PV because the threads didn't match. in the pic below the left side upper line that slopes I made, the lower one that zigs up and down my mechanic made last year. That meant trip to Autozone to rent a line flare tool and brake line nuts. I still have some spooled brake line from last summer when I replaced all the rear lines. That cheap flare tool is a real pain. Alot of trial and error. But I finally got a useable adaptor for the front brake output. Only one output had wrong thread size but I had bought 2 adaptors and needed only one. You can see the adaptor on the lower right side.

I wasn't able to bleed the brake yesterday when I installed the parts but I did pump the brake pedal and checked for leaks and there are none, including the brake light sensor. I used the cap screw to hold the internal piston secure while bleeding the brake, no leaks when bleeding them and the cap screw was bone dry when I pulled it out.

I put the brake light sensor that came with it back in and plugged in the pigtail. And I get brake light when I engage the E brake, but it flickers weakly. I'm assuming the LED I put there just isn't getting enough voltage to light up fully so next time I pull the cluster I'm putting an incandescent bulb back in for the brake light, unless there's a LED that can be used for that application. . I think that will solve the flicker.

This pic was taken yesterday with the piston cap screw still in place. I self bled once with a Snapple bottle and a second time with my wife working the brake pedal and me under the car. The pedal is solid now no fade but I wont drive till tomorrow. I'll post back with an update.

Just out of curiosity OldFox, or anyone who knows, comparatively, what's the difference between the stock PV that came with the 84 Mustang and this aftermarket part advertised for 60 - 70 Mustang, Fairlane, Galaxy, Comet and I have seen it listed for Mercury Capri 79 - 86.

https://www.amazon.com/dp/B0899FZTNG...roduct_details




One last thing, I noticed my rear passenger drum was sloppy so I pulled it and the self adjuster hardware all fell out. That may be part or all of why I lost braking power last week. I put it back together, if it happens again Ill have to replace that hardware.

[fgross2006]

I took the Mustang for a run around the block and the brakes are great. High pedal, nice grabbing power, I tried to lock up but no matter how hard I slam the brakes it brings me to a speedy smooth stop. Im taking it on a parkway run to go to my doc again. That will be the real test.

[fgross2006]

I took it for a spin on the parkway and the car drives great. Brakes are great. Pedal is high, stops on a dime, no fishtailing or wagging in the rear like before.

So I can attest the aftermarket proportioning valve I got from Amazon worked great. Keep in mind other buyers have said they had leaks so no 100% affirmation form me on the many sellers offering those 60 to 70 Mustang PV's. Also virtually all buyers complain that the bracket comes installed backwards. If you get one, you'll have to finesse the bracket off and correct its position.

I got lucky in that mine came with no bracket and I found a seller with just the bracket. The stock and aftermarket parts all look like the bracket was stamped in the factory. I wasn't comfortable to take a chisel to the thing, so I used JB Weld, its not coming off ever.

I'm so glad that's over. In the list of tough things I've dealt with on my 84 vert, this is up there with rebuilding the rear quarter window guide bars and re-adjusting them.