Prop./ Brake valve

[496dart]

Ok guys, i need to know what you did as far as your proportional valve after the disc conversion.  My car is a 70 dart and i put 73' discs up front.

I have what is believed to be a 73-76 A body prop valve.  when i place it up on the frame,  none of the lines match up , as far as size and  rear/ front ports .   It really looks like i have to make all new brake lines  . 

Is this what you guys had to do---or   how did you route everything  ?

[Jim_Lusk]

I've always used the 73-76 a-body piece. You may have an F-body prop valve. Can you post a pic?

[496dart]

here it is:

[attachment deleted by admin]

[Jim_Lusk]

Definitely NOT an a-body piece.

[496dart]

figures--i was told it was and bought it online .

anyone have one on here ?

[Jim_Lusk]

I don't have a spare one, but might be able to get a pic of one so you know what you're looking for.

[ski]

Here's one.

[attachment deleted by admin]

[496dart]

thanks - can u list what each letter corresponds to ?

[ski]

Sorry,

A= master cylinder marked F for front, be careful it's actually the rear reservoir. 
B= right front brake
C= left front brake
D= rear brakes.  They'll split downstream
E= Master cylinder marked R, again be careful this is the front or usually smaller reservoir.

B & C probably can be either way but A & E have to be correct.  You want the larger reservoir to apply the front brakes.

Thanks to Ryan from N.H. for applying the letters to the picture. 

[496dart]

thanks !

[larry408]

I have a extra a-body proportional valve but it is packed for the move that we are making this weekend. If you do not find one and are interested in the one that I have just let me know and I will look for it next week.

[440WIP]

This is handy information.
Is it possible to put this thread (of the picture and the description) up into the tech pages?

[Sixpak]

I took this one out of a 75 Dart with factory discs....

[attachment deleted by admin]

[496dart]

hmmmm......that one looks just like the one i already have. 

[ski]

The one I posted came out of a 73 Valiant with factory disc brakes.


... it was the newer single piston type not the earlier K/H.

[DartKnight]

Weird...the bottom one looks like a B or E-body valve; The one I pulled for my brake swap came from a 74 Swinger with single-piston calipers and looks like the one ski posted. The other ones look like the valve I pulled out of my 74 Charger...I'm a little confused, also.  If it is a dual-piston/single-piston difference, would either one work?

[496dart]

confused here too !

my car has 73' single pistons

[Ed]

All my pre-73 cars have the brass square prop valve.  Ma mopar switched over to the cast iron valves sometime in the early 1970's except in trucks. 

[ski]

I'll see if I can dig out a 72 and earlier that went with the 4 piston K/H type.  If I remember right they look similar to the one I posted but not exactly.  It may take me a couple days to locate one.  Hey 496dart I would just get a 35 dollar adjustable one and plumb it into your rear brakes.

[496dart]

i  might do that--who has them for $35?

i got another one on the way  to try first

[Lars]

Summit Racing has them. Use the old drum valve and plumb the adjustable one into the line that feeds the rear brakes.

[ski]

i  might do that--who has them for $35?

i got another one on the way  to try first

Take a look at the last one labeled 65-72 MOPAR.  Kind of looks like the one you have.

http://www.piratejack.net/proportioning_valves.html

[Sixpak]

I believe the factory started doing a slow transition from brass prop valves to the cast iron ones around the early 70's. Earliest example I can recall of seeing a cast iron valve is in a 71-72 C b body, then I think the E bodies got them in 72 or 73, probably the B bodies around then. I've seen brass valves in A bodies through 74 but after that in 75 most if not all had the cast iron valves. It's just a matter of the factory using up whatever they had in stock and then switching over to something else.

[496dart]

Thats gotta be the one i already have Ski

[moparrr07]

it shows in my 75 chrysler chassis manual that every line had a cast one

[Jim_Lusk]

I just pulled two of the brass ones out of a yard today, along with the spindles. I didn't check the year of the cars, though.

[wedgie]

I know that the combination valve proportions front to rear, and turns on the brake malfunction light, but does it also contain the residual valve?

[67 dartgts]

  Let me see if I understand and can confuse everything even more  The photo that Ski posted iss of the Safety Switch its function is to split the front wheel lines and warn of a system failure frot or rear.  The faiilure would be a break in the system that allows the fluid to drain to the point where the spring pressure inside the switch makes contact turning on the light .  To tell you you have lost fluid..the other system will of course work because it is complety seperate from the other.  If you took the safety switch out of the system.  The rear section of the Master plumbs direct and splits at the rear end.  The front section you can split with a tee to do the right and left.  There is no connection to the front and rear inside the switch.  The proporating valve merly allows you to adjust pressyure to the rear so all wheels brake equally..that is in a panic stop you lock front and rear wheels equally.

  Maynard

[attachment deleted by admin]

[Cudadust]

This is getting a little confusing, those early renditions were distribution valves with a position forow fluid pressure.  The later model combination valves provided some proportioning but this was negated with different tire\wheel combinations. The stand alone proportioning valve is installed in the rear brake circuit and adjusts the amount pressuse to the rears as a safety feature to prevent the rears from locking up first and causing the rear end to come around. www.moparaction.com is the definitive source for brake conversions on Mopar iron and should be consulted for more information.

[ski]

http://www.piratejack.net/troubleshooting/valveFAQ.htm