Resetting Brake proportion valve?

[MellowCharger]

Hi

My 69 Charger has a problem with the rear brakes being far more efficient that the fronts.

Someone mentioned that the proportioning valve that sits under the M/C has clicked over pushing all power to the rears. This means that I must have a problem with the front lines somewhere but it's not apparent.

How do I reset the valve so that I get normal braking?

Your help is much apreciated.

rgds
lee

[John_Kunkel]

Is your car have drum brakes front and rear? If so, there is no proportioning valve, the brass connector that the MC lines merge in is merely a splitter. If there were an imbalance in the system your dash brake warning light would be illuminated.

[MellowCharger]

Hi John.....The car haspower brakes and discs up front.

All my lights are up the swanny.....not much works inside.

thanks

[John_Kunkel]

The '69 prop valve isn't under the MC like on the later cars, it's mounted all by itself lower on the frame. The valve doesn't actually "click over", it just limits the pressure to the rear brakes under heavy braking.

I think you're referring to the differential piston inside the splitter that triggers the warning light; when it moves to one side or the other it doesn't affect the pressure.

[MellowCharger]

You're right John...That must be what I'm refering too.

What do you think is causing the problem I have?

[resq302]

possibly an internal leak inside the master cyl?  possible obstruction in the lines, like rust or collapsing rubber line?

[MellowCharger]

My first thoughts were leaking m/c but that appears to be ok.

I'm replacing the hoses although they look fine and I will report back....I'm sure it's not gonna be that simple.

I have 2 chargers. A 68 and a 69 which I bought this year and I don't think I've used either for more than a day without something going wrong........Oh the joys of motoring.

[Nacho-RT74]

disc/drums setup uses a different dist block as far I know.

[John_Kunkel]

My first thoughts were leaking m/c but that appears to be ok.

An internal leak (bypassing) won't show up visually and with no working warning light you don't know if there's an imbalance.

[Chatt69chgr]

A good site that sells new proportioning valves and also explains how the darned things work is:

http://www.piratejack.net/

Might take a look to see if anything they say helps.  You can take your proportioning valve apart and clean/inspect it.  There are some rubber parts inside and I would venture to say that none of these items are or ever will be available.  There is a reproduction of the later cast iron proportioning valve that is identical to the MOPAR unit.  I think 73 up.  But not a reproduction of the brass one you have.  Now if anyone knows of a repop of the brass unit, I would sure like to know about it.