开云体育

I am 90% sure I got the proportioning valve centered. It took some effort to get the groove exactly where it should be.?

I found the switch was loose when I removed it.? I also found the cluster brake light would still come on after centering with the switch snugged up.? If I screwed the switch out about 1/4 turn the cluster brake light would go out.? The switch/proportioning valve contact surface looked like the plastic switch had been over torque at some time in its life and that may be the reason it was loose when I remove it and why the light would go on when the switch was snugged up.? I put a 0.009" thick mylar washer in the switch/proportioning valve?contact?surface area and that kept the light from coming on when snugged up.? Hopefully, that is not just overriding a non-centered valve.

When I had the switch out, I did some ohm resistance testing to determine if the switch was working properly and get an idea of how it functions.? I found the pin in the switch is also the ground as well as the switch actuator.? When the pin is extended it is an open circuit.? Once the pin is pushed in far enough, the switch makes contact, and the circuit is completed to ground to activate the light.? What I don't understand is the basically zero resistance between terminals going to the wires of the switch.? I am not sure why that is unless it is a redundant feature in case one wire circuit fails. Then again, it could be part of the parking brake circuit to activate the light.

I will keep an eye on things to see if they function as they should.

Gary in SoCal

On Friday, April 25, 2025 at 08:45:50 AM PDT, Gary Wittman via groups.io <gary.wittman@...> wrote:

Chris, Yes it is a 69.? I am not going to do anything with the master cylinder yet. If I do, I will do some searching myself first.? If I run into problems, I will reach out to you.? Thank you for the offer.?

Gary in SoCal

On Thursday, April 24, 2025 at 11:35:20 PM PDT, Chris Scheers <chris@...> wrote:

Be careful. For at least the drum brakes, the
Mustang and Galaxie master cylinders have a different bore than the Fairlanes.

If you need me to look up the bore size for disc brakes, I can. I assume 1969?



At 02:03 PM 4/23/2025, Doug Frame via groups.io wrote:

>I usually look up 69 Mustang for these parts.
>That what I did for mine. My car had 49000
>original miles and I needed to take it apart the
>proportioning valve,? and rebuilt it to fix
>mine. Get some flair nut sockets they work good in tight locations.
>Doug Frame
>
>>On Apr 23, 2025, at 12:01, Gary Wittman via
>>groups.io <gary.wittman@...> wrote:
>>
>>???
>>Thank you for all the suggestions.? I think the
>>first thing I will try is the centering with an
>>awl through the switch hole.? I am guessing
>>brake fluid will flow out with the switch
>>out.? Yes, I don't know which side the piston
>>is on, so the jumping on the brake pedal method could be problematic.
>>
>>I really don't want to take the valve apart but
>>can do that as a last resort.? That is probably
>>something I will do if I have to remove the
>>master cylinder for rebuild or replacement.
>>Doug, do you have source for a rebuild kit for
>>the master cylinder?? I think I may need to fix the master cylinder eventually.
>>
>>Gary in SoCal
>>
>>On Wednesday, April 23, 2025 at 06:49:06 AM
>>PDT, Doug Frame via groups.io <dframe@...> wrote:
>>
>>
>><C7ZZ-2B091-CK_P1.jpg>
>><
>>crh5WLMFNKSj0aPkpwaS1kre3KaZi-lRyjiZt5tE>BRAKE
>>PROPORTIONING VALVE REBUILD KIT - 67-69 MUSTANG/COUGAR DISC BRAKE
>><>cgfordparts.com
>>You will need this and the tool take apart and clean, rebuild.
>>Doug Frame
>>
>>>On Apr 23, 2025, at 08:16, Linc via groups.io
>>><linc@...> wrote:
>>>
>>>???
>>>It can be tedious, but if your valve will not
>>>self center the you need to take the block
>>>apart and clean it.? You can reach down into
>>>the switch hole and center it yourself with a
>>>awl or other pointy tool. I have done this before.
>>>
>>>Best of luck
>>>
>>>--
>>>
>>>
>>>============================================================
>>>? I am Linc..... What more could you possibly need to know?
>>>============================================================
>>>
>>>
>>>On Tue, 2025-04-22 at 20:12 +0000, Gary Wittman via groups.io wrote:
>>>>Doug,
>>>>That sounds like a great tool for bleeding
>>>>the brakes and keeping the proportioning
>>>>valve centered.? However, that is not my
>>>>issue.? My proportioning valve appears to be
>>>>off center, and I need to center it.
>>>>
>>>>Gary in SoCal
>>>>
>>>>On Tuesday, April 22, 2025 at 11:37:50 AM
>>>>PDT, Doug Frame via groups.io <dframe@...> wrote:
>>>>
>>>>
>>>><>Adjustable
>>>>Proportioning Valve Bleeder Tool,Aluminum
>>>>Brake Proportioning Valve Bleeder Tool of
>>>>Brake Bleeder,Drum Brake Tool Car Accessories
>>>>Compatible with DISC/DRUM PV2&PV4 AC 172-1371
>>>><>a.co
>>>><><inline.0.part>
>>>>
>>>>Doug
>>>>More Car Than Cent
>>>>
>>>>>On Apr 22, 2025, at 13:11, Gary Wittman via
>>>>>groups.io <gary.wittman@...> wrote:
>>>>>
>>>>>???
>>>>>The last time I drove my Cobra; the
>>>>>instrument cluster brake light came on.? The
>>>>>brakes still seemed to work normally.? I
>>>>>disconnected the electrical connector to the
>>>>>proportioning valve and the light went
>>>>>out.? So, I tried centering it and the light
>>>>>is still on when the electrical connector is connected, and ignition is on.
>>>>>
>>>>>The centering method I used was to slowly
>>>>>bleed the front brakes with three full pumps
>>>>>as I was watching the cluster brake
>>>>>light.? It always stayed on.? I then slowly
>>>>>bled the rear brakes with three full pumps
>>>>>and again the brake light stayed on.? The
>>>>>pedal sank to full stop with both bleedings.? Is there something I am missing?
>>>>>
>>>>>Is there anything else that would cause the
>>>>>cluster brake light to come on?? It seems
>>>>>that if disconnecting the proportioning
>>>>>valve electrical connector makes the cluster
>>>>>brake light go out, it must be the proportioning valve activating it.
>>>>>
>>>>>I have noticed for a while that when sitting
>>>>>at a stop light with the brakes on and in
>>>>>gear, the brake pedal seems to very slightly
>>>>>creep down, but the brakes still hold.? I
>>>>>have no brake fluid leak so there could be
>>>>>an internal leak in the master cylinder.? It
>>>>>was replaced several years ago but it does
>>>>>not have many miles on it.? The brake fluid is clear.
>>>>>
>>>>>Any suggestions?
>>>>>
>>>>>Gary in SoCal
>><C7ZZ-2B091-CK_P1.jpg>