Combination valve connections

[Mike Szadaj]

I am not sure how the lines connect to this valve. Looking at the picture, starting from the right and going clockwise, I believe it connects as follows; to rear master cylinder, to rear brakes, to front master cylinder, to front, to front. If correct, does it matter which front goes to which side?

 

[R/T Boy 67]

 

[Mike Szadaj]

Thank you, sir.

 

[Mike Szadaj]

Can this valve be installed in the position shown in the photo, with the brake warning light switch pointed down?

 

[R/T Boy 67]

Yes, it can be installed any way you like.

 

[Mike Szadaj]

Thanks again.

 

[Mike Szadaj]

Why is there a bleeder valve on it? Does this valve require bleeding, or is the air expelled from it as the brakes are being bled?

 

[R/T Boy 67]

That is the metering valve which holds back pressure to the front discs until there is a little pressure on the rear drums. When bleeding the brakes sometimes air gets trapped in the valve and it won't open properly. If you can't get fluid at the caliper bleeders, then you have to pull on that little stem and keep it open while bleeding. I have never had to do it.

 

[1 Wild R/T]

That is the metering valve which holds back pressure to the front discs until there is a little pressure on the rear drums. When bleeding the brakes sometimes air gets trapped in the valve and it won't open properly. If you can't get fluid at the caliper bleeders, then you have to pull on that little stem and keep it open while bleeding. I have never had to do it.

And there's a tool for that...

 

[1 Wild R/T]

And there's a tool for that...View attachment 828378

And here's another tool that does a similar job on a different part of the valve

 

[Mike Szadaj]

Thanks guys.

 

[R/T Boy 67]

Those special tools exist for a reason, but I have never had to use them on a mopar. The pressure differential valve is self centering on all the mopar valves I have seen. If you gravity bleed the calipers to get most of the air out, before you pump the pedal, you should have no trouble with the metering valve. It has always worked for me.

 

[R/T Boy 67]

Just to clarify my above post. The metering valve does not shut off the front circuit 100%. It alows some fluid to pass when closed, so gravity bleeding is possible.

 

[383man]

The pain is if the pressure diff valve moves over when bleeding or before bleeding from a loss of fluid in one half the system then the brake light will come on and then you wont get much fluid out of 1/2 the system. I have had that cause pretty much no fluid to the rear brakes when the valve went off center from a fluid leak. Then you have to bleed it to get the valve to move back over so you can bleed the rear. But as said I like to gravity bleed the brakes first as most of the time I can get almost a full pedal from gravity bleeding long enough. I actually bled the complete brake system on my 63 by myself gravity bleeding. And its a dual master cyl as I upgraded it to a dual system. Ron

 

[1 Wild R/T]

The pain is if the pressure diff valve moves over when bleeding or before bleeding from a loss of fluid in one half the system then the brake light will come on and then you wont get much fluid out of 1/2 the system. I have had that cause pretty much no fluid to the rear brakes when the valve went off center from a fluid leak. Then you have to bleed it to get the valve to move back over so you can bleed the rear. But as said I like to gravity bleed the brakes first as most of the time I can get almost a full pedal from gravity bleeding long enough. I actually bled the complete brake system on my 63 by myself gravity bleeding. And its a dual master cyl as I upgraded it to a dual system. Ron

When the valve moves off center you can unscrew the switch & use a scribe through the hole to center the valve... Then screw in the tool till you finish bleeding brakes then reinstall the switch...

 

[383man]

When the valve moves off center you can unscrew the switch & use a scribe through the hole to center the valve... Then screw in the tool till you finish bleeding brakes then reinstall the switch...

I like that tool you posted also that when screwed in will keep the press diff valve centered. Ron

 

[1 Wild R/T]

I like that tool you posted also that when screwed in will keep the press diff valve centered. Ron

Yeah, funny I never had a Mopar fight me to the point I felt I needed it, but I worked on a few Chevies that drove me nuts... Then I got that tool & never had another issue...

 

[R/T Boy 67]

Mopar valves of that era were self centering.

 

[1 Wild R/T]

Mopar valves of that era were self centering.

True but when they get old & crusty they can stick....

 

[383man]

Yeah, funny I never had a Mopar fight me to the point I felt I needed it, but I worked on a few Chevies that drove me nuts... Then I got that tool & never had another issue...

My buddies 69 Camaro gave me a fit but eventually I got it. Ron