Brake light pressure switch problems

[ksschraml]

my brake light pressure switch is leaking fluid out of the center, where the wires go, when pressure is applied to the pedal. bought a new one from ford but its doing the same thing! anyone had this happen, how did you fix it?

 

[computercarguy]

I just found that mine is leaking too. Trying to get the front brakes bled is about the last hurdle I have left and I keep getting air. Discovered the leak from the pressure switch. Does anybody know if this switch is exposed to brake fluid or is it supposed to live in a dry environment pushed by a pressure valve?:huh:

 

[jeff8877]

Yep...had the same problem. It is not the switch that is leaking but your proportioning valve. You need a rebuild kit from... https://www.musclecarresearch.com/valve-kit-kh

I installed the kit on mine and leak went away.

 

[eddyw]

Yep...had the same problem. It is not the switch that is leaking but your proportioning valve. You need a rebuild kit from... https://www.musclecarresearch.com/valve-kit-kh

I installed the kit on mine and leak went away.

+1 ::thumb::

 

[computercarguy]

Thanks, that is what I was afraid of.

 

[kcmash]

Thanks, that is what I was afraid of.

I did the kit and now mine is leaking at this spot. ? Does that mean I am too incompetent to rebuild a proportioning valve?

 

[nailpounder]

http://mustangparts.averagejoerestoration.com/content/images/thumbs/0000248_C8AZ-2B264-A_320.jpeg

might try a different type i belive 69 and 70 are the same as 71-73

 

[Bill73Ragtop]

Brake fluid is leaking past the O-ring seals on the ends of the piston in the center bore of the proportioning unit.

 

[kcmash]

Brake fluid is leaking past the O-ring seals on the ends of the piston in the center bore of the proportioning unit.

With the new seal kit is there any chance this will go away with a few cycles of the brake system/pedal, or do I need to just buy one of the Daniel Carpenter reproductions that are out now?

 

[Bill73Ragtop]

I rebuilt the distribution valve on my 69 and there is no leakage (there wasn't any to begin with) so rebuilding it will not hurt it. I think new O ring seals should work unless you have damage to the bore. Rebuild kits are cheap so it's probably the way to begin. BTW - be sure to get the 'Centering Tool' which is helpful during the bleeding process.

 

[kcmash]

I rebuilt the distribution valve on my 69 and there is no leakage (there wasn't any to begin with) so rebuilding it will not hurt it. I think new O ring seals should work unless you have damage to the bore. Rebuild kits are cheap so it's probably the way to begin. BTW - be sure to get the 'Centering Tool' which is helpful during the bleeding process.

I tried to follow all the rebuild instructions, and I did go for the centering tool. I am converting mine to disk, I decided to rebuild because it was leaking out of the bottom. Now that that part is sealed it is leaking through the switch!!!

 

[kcmash]

I rebuilt the distribution valve on my 69 and there is no leakage (there wasn't any to begin with) so rebuilding it will not hurt it. I think new O ring seals should work unless you have damage to the bore. Rebuild kits are cheap so it's probably the way to begin. BTW - be sure to get the 'Centering Tool' which is helpful during the bleeding process.

I tried to follow all the rebuild instructions, and I did go for the centering tool. I am converting mine to disk, I decided to rebuild because it was leaking out of the bottom. Now that that part is sealed it is leaking through the switch!!!

 

[Bill73Ragtop]

I'm hoping someone will chime in with shared issue that they resolved. Is it leaking at the nylon threads or through the middle of the switch?

I'm thinking there should not be a lot of psi coming through that part of the valve (if any) since it's isolated from fluid pressure by the seals. Brake system psi is hundreds of pounds so a snugged in nylon threaded unit is not all that strong as compared to steel fittings securing the flared line. Is it possible one of the new O-rings rolled when you reinstalled the piston?

 

[kcmash]

OK, I am ANGRY! I rebuilt mine using the kit and it leaks all over. Is there any way to test these things off the car and save the paint on the restored body?

Please help. I am ready to buy a reproduction if it will work!

Kcmash