proportioning valve trouble

[wayne70]

I gutted the PV, removed the plunger and spring. This is a newer disc/disc PV on a 70 chevelle that i am upgrading to c6 brakes.
After gravity bleeding all caliper's i went to do the pump and bleed method just to make sure all air was removed from the system, after the second pump of the pedal brake fluid is leaking from Pv.
Looking at the PV there is a spot on the side that had what looked like a small rubber seal and a star washer holding it in place, that blew out and i lost all the fluid for the rear brakes.
I have installed an adjustable PV after the master cyl. and before the frame mounted PV and was going to use the PV on the frame as a junction block.
Has anyone had this happen ? What did you do to repair this.

[dhutton]

Maybe you could replace it with a Wilwood residual pressure valve. I think they have one that is 2 psi.

[wayne70]

Here is a picture of what I removed from PV

[Apogee]

Did you replace the o-ring seal when you reinstalled the rear port into the block?

Tobin
KORE3

[wayne70]

I replaced the o-ring. I think the best way to solve this is to run a new 3/16 line to the rear hose connection and get rid of the original PV.

[MonzaRacer]

agreed

[67RSRAG]

had the same issue with a PV from MBM after 2 months less than 200 miles on it. replaced with a new one let's see how long this one lasts

[MCB Matt]

Keep in mind....with that type of prop valve you can not pump and hold bleed them. As soon as you hit the pedal the pressure in the front will build faster than the rear and the pin in the valve will see that as a pressure loss and slide to close off about 90% of the flow to the rears.

Younreally need to pressure bleed or vacuum bleed them...motive products makes a great affordable pressure bleeder!

Matt

[Scott Parkhurst]

I don't even run a junction-type PV anymore. My fronts are plumbed direct from the master with a T between L and R, and the rears have a Baer adjustable PV mounted under the master. Once I adjusted the rears to be in sync with the fronts, it's all set and I don't have to mess with it at all. Get the whole stock type PV out of there, and your headaches will go with it. Nothing to be gained by keeping it.

[pitts64]

I would remove that original set up and install a Summit adjustable proportion valve. You will also need the metering valve.. I bought mine from Master Power..

http://www.mpbrakes.com/products/pro...product_id=615

http://www.summitracing.com/search/?keyword=g3905&dds=1

I've been gravity bleeding my brakes for 35 years without any troubles..

[a67]

The metering valve isn't required on a disc/disc set up. Just plumb the proportioning valve between the M/C and rear line.

Bob.