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A Body disc brake swap - proportioning valve. #1412235 03/31/13 03:46 PM 03/31/13 03:46 PM
Joined: Mar 2003 Posts: 4,930 Tri-Cities, Washington V VITC_GTX OP master
VITC_GTX OP master V Joined: Mar 2003 Posts: 4,930 Tri-Cities, Washington	1969 Barracuda; I put '73 A body disc brake spindle/calipers on. The rear brakes don't seem to work unless I hit the pedal very hard. Also, after they are activated they don't release very well (drag a lot). The car still has the original proportioning valve, is it required to change that out when going from older drums to newer discs? If so, is there a drop in valve that I can buy that won't require me to redo the lines (bending lines/new fittings)? Last edited by VITC_GTX; 03/31/13 03:47 PM.

Re: A Body disc brake swap - proportioning valve. [Re: VITC_GTX] #1412236 03/31/13 03:52 PM 03/31/13 03:52 PM
Joined: Feb 2005 Posts: 957 MI, Lapeer M maximus super stock
maximus super stock M Joined: Feb 2005 Posts: 957 MI, Lapeer	You will have to use the valve for the disc brake front and drum rear if that is your new set-up. There should be no or minor bending to accept the new valve. Contact In-Line Tubing in Shelby Township, Michigan. They sell everything you need. Or you can get a used disc/drum valve from a junkyard if you want to go that route.

Re: A Body disc brake swap - proportioning valve. [Re: VITC_GTX] #1412237 03/31/13 04:45 PM 03/31/13 04:45 PM
Joined: Nov 2003 Posts: 36,041 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,041 Lincoln Nebraska	I put 74 A discs on my 65 dart & kept the OE drum splitter & NO issues. 10" rear drums/alum dual bowl M/C. bowl next to firewall to front discs/forward bowl to rear drums. Likely an issue with the OE prop valve. I'd open it up & see what's stuck or I wouldn't be afraid to gut it & convert it to an open splitter & avoid having to rebend lines. live every 24 hour block of time like it's your last day on earth

Re: A Body disc brake swap - proportioning valve. [Re: VITC_GTX] #1412238 03/31/13 04:56 PM 03/31/13 04:56 PM
Joined: Jan 2010 Posts: 1,089 st.cloud fl D d-150 Smarter than a 5th grader?
d-150 Smarter than a 5th grader? D Joined: Jan 2010 Posts: 1,089 st.cloud fl	sounds like you still have air in the line

Re: A Body disc brake swap - proportioning valve. [Re: RapidRobert] #1412239 03/31/13 09:35 PM 03/31/13 09:35 PM
Joined: Sep 2007 Posts: 14,889 up yours Supercuda About to go away
Supercuda About to go away Joined: Sep 2007 Posts: 14,889 up yours	Quote: I put 74 A discs on my 65 dart & kept the OE drum splitter & NO issues. 10" rear drums/alum dual bowl M/C. bowl next to firewall to front discs/forward bowl to rear drums. Likely an issue with the OE prop valve. I'd open it up & see what's stuck or I wouldn't be afraid to gut it & convert it to an open splitter & avoid having to rebend lines. There IS NOTHING in a drum splitter. NOTHING You'd know that if you understood how a braking system works. They say there are no such thing as a stupid question. They say there is always the exception that proves the rule. Don't be the exception.

Re: A Body disc brake swap - proportioning valve. [Re: Supercuda] #1412240 03/31/13 10:09 PM 03/31/13 10:09 PM
Joined: Nov 2003 Posts: 36,041 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,041 Lincoln Nebraska	Quote: [here IS NOTHING in a drum splitter. NOTHING You'd know that if you understood how a braking system works. Having a bad day there bro . HE mentioned having a prop valve which means he's swapping the 4 piston KH brakes out (which have a prop valve) for the 73 single piston ones (very likely if swapping to a big bolt pattern rear) or he's swapping the front drums for 73 A discs & he is mistakingly calling the splitter a prop valve. (re) read his post & get your facts straight before you run your mouth live every 24 hour block of time like it's your last day on earth

Re: A Body disc brake swap - proportioning valve. [Re: RapidRobert] #1412241 03/31/13 10:14 PM 03/31/13 10:14 PM
Joined: Feb 2003 Posts: 8,020 Pangaea B5 Bee master
B5 Bee master Joined: Feb 2003 Posts: 8,020 Pangaea	Easy there boys, you're both correct, sort of. The OP mistakingly called the distribution block a proportioning valve and he mentions he went from older drums to newer discs.

Re: A Body disc brake swap - proportioning valve. [Re: B5 Bee] #1412242 03/31/13 10:36 PM 03/31/13 10:36 PM
Joined: Mar 2003 Posts: 4,930 Tri-Cities, Washington V VITC_GTX OP master
VITC_GTX OP master V Joined: Mar 2003 Posts: 4,930 Tri-Cities, Washington	Yeah, maybe I am using the wrong words. I believe the car was originally 4 drums but I don't know for sure because when I got the car it had the big bolt pattern discs up front. So if this was a drum car originally then this piece I am talking about is just a distribution block and not a proportioning valve? If that's the case is there any reason in replacing it? What has me baffled is the fact that the rear brakes do not come on at all until I push down VERY hard and then the rear brakes won't release after the pedal is released.

Re: A Body disc brake swap - proportioning valve. [Re: VITC_GTX] #1412243 03/31/13 10:53 PM 03/31/13 10:53 PM
Joined: Nov 2003 Posts: 36,041 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,041 Lincoln Nebraska	Yes if it was originally 4 wheel drums it would have originally have had a distribution block AKA as a splitter. First thing I'd do is look up under there & see what you have since front discs have already been swapped on by a PO. You have a blockage somewhere. Last edited by RapidRobert; 03/31/13 10:57 PM. live every 24 hour block of time like it's your last day on earth

Re: A Body disc brake swap - proportioning valve. [Re: VITC_GTX] #1412244 03/31/13 10:53 PM 03/31/13 10:53 PM
Joined: Nov 2005 Posts: 15,119 85086 moparpollack Lil Herman
moparpollack Lil Herman Joined: Nov 2005 Posts: 15,119 85086	I say the calipers pistons are stiff from sitting. What master cylinder are you using? How old are the lines? I had a car where the lines looked new but the insides were gunked up from old fluid. 56 Plaza 63 D100 step side 67 Coronet, 68 Roadrunner, 69 Super Bees, 69 Coronet 500 convertible, 70 Roadrunner Post, 79 D150 360, and a severe case of Mopar a,d,d

Re: A Body disc brake swap - proportioning valve. [Re: RapidRobert] #1412245 03/31/13 11:01 PM 03/31/13 11:01 PM
Joined: Nov 2005 Posts: 15,119 85086 moparpollack Lil Herman
moparpollack Lil Herman Joined: Nov 2005 Posts: 15,119 85086	Quote: Yes if it was originally 4 wheel drums it would have originally have had a distribution block AKA as a splitter. First thing I'd do is look up under there & see what you have since front discs have already been swapped on by a PO. You have a blockage somewhere. 56 Plaza 63 D100 step side 67 Coronet, 68 Roadrunner, 69 Super Bees, 69 Coronet 500 convertible, 70 Roadrunner Post, 79 D150 360, and a severe case of Mopar a,d,d

Re: A Body disc brake swap - proportioning valve. [Re: moparpollack] #1412246 03/31/13 11:26 PM 03/31/13 11:26 PM
Joined: Mar 2003 Posts: 4,930 Tri-Cities, Washington V VITC_GTX OP master
VITC_GTX OP master V Joined: Mar 2003 Posts: 4,930 Tri-Cities, Washington	Quote: I say the calipers pistons are stiff from sitting. What master cylinder are you using? How old are the lines? I had a car where the lines looked new but the insides were gunked up from old fluid. Master cylinder is a rebuilt unit for a disc brake car (73 Duster). I blew out all the lines before I put everything together. I did not try to blow out the splitter though. Maybe something is plugged up in there? Is the splitter simply a block with no valves, just a fancy tee with one inlet and three outlets? Last edited by VITC_GTX; 03/31/13 11:35 PM.

Re: A Body disc brake swap - proportioning valve. [Re: VITC_GTX] #1412247 03/31/13 11:29 PM 03/31/13 11:29 PM
Joined: Jan 2003 Posts: 6,531 Jacksonville, FL Chris2581 master
Chris2581 master Joined: Jan 2003 Posts: 6,531 Jacksonville, FL	FWIW... I put Wilwood HD brakes on the front of my 71 Demon and all I did was change the front brakes over and install one of Ehrenberg's Mopar master cylinders.My Dana already had 10" drums from a B-body on the rear when the car had the OEM 10 front drums and my brakes work great. Nautilus Racing- We use Superformance gaskets and Turbo Action converters/products.

Re: A Body disc brake swap - proportioning valve. [Re: RapidRobert] #1412248 03/31/13 11:34 PM 03/31/13 11:34 PM
Joined: Mar 2003 Posts: 4,930 Tri-Cities, Washington V VITC_GTX OP master
VITC_GTX OP master V Joined: Mar 2003 Posts: 4,930 Tri-Cities, Washington	Quote: Yes if it was originally 4 wheel drums it would have originally have had a distribution block AKA as a splitter. First thing I'd do is look up under there & see what you have since front discs have already been swapped on by a PO. You have a blockage somewhere. How can I tell if I have a splitter or a proportioning valve?

Re: A Body disc brake swap - proportioning valve. [Re: VITC_GTX] #1412249 04/01/13 12:39 AM 04/01/13 12:39 AM
Joined: Feb 2003 Posts: 8,020 Pangaea B5 Bee master
B5 Bee master Joined: Feb 2003 Posts: 8,020 Pangaea	A bad rear brake hose is another possibility. They sometimes rupture internally creating a flap that will block the fluid flow. Usually it blocks during release making the brake slow to release but can also block during brake apply, and maybe both apply and release.

Re: A Body disc brake swap - proportioning valve. [Re: VITC_GTX] #1412250 04/01/13 12:48 AM 04/01/13 12:48 AM
Joined: Nov 2003 Posts: 36,041 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,041 Lincoln Nebraska	Quote: Is the splitter simply a block with no valves, just a fancy tee with one inlet and three outlets? Yes, a basic T block & a prop is larger/more complicated as it contains valving. I wonder if the rear flex hose has collapsed internally. EDIT I'd jack up all 4 corners & see how much braking you do have. Something ain't right here in the symptoms Last edited by RapidRobert; 04/01/13 01:05 AM. live every 24 hour block of time like it's your last day on earth

Re: A Body disc brake swap - proportioning valve. [Re: RapidRobert] #1412251 04/01/13 02:15 AM 04/01/13 02:15 AM
Joined: Mar 2003 Posts: 4,930 Tri-Cities, Washington V VITC_GTX OP master
VITC_GTX OP master V Joined: Mar 2003 Posts: 4,930 Tri-Cities, Washington	Quote: Quote: Is the splitter simply a block with no valves, just a fancy tee with one inlet and three outlets? Yes, a basic T block & a prop is larger/more complicated as it contains valving. I wonder if the rear flex hose has collapsed internally. EDIT I'd jack up all 4 corners & see how much braking you do have. Something ain't right here in the symptoms I did remove the rear flex hose and blew compressed air through it. It seemed to have no restrictions at all. I'm wondering if my splitter/proportioning valve is where the blockage is

Re: A Body disc brake swap - proportioning valve. [Re: VITC_GTX] #1412252 04/01/13 04:13 AM 04/01/13 04:13 AM
Joined: Jan 2003 Posts: 27,421 Balt. Md 3 383man Too Many Posts
383man Too Many Posts 3 Joined: Jan 2003 Posts: 27,421 Balt. Md	When I put front disc on my boys Dart I got the right combination valve from an A-body with the disc/drum setup. You have to remember the disc brake combo valve has the prop valve and the metering valve in it plus it has the light switch to turn the dash brake lite on if you lose one side of the master cyl. Of course the prop valve limits the press to the rear brakes on hard braking so the rear wont lock right up with the front down and not much weight at the rear of the car when braking hard. The metering valve keeps the front disc brakes from applying to much on light brake pedal application until the rear drum brakes overcome the spring tension and start to work. Without the metering valve on light brake pedal applying the disc would be doing all the stopping since they have no return springs on disc and they would apply to much before the rear start to work and most likely would wear the pads out to fast. But the few I did I always but the right disc/drum combo (prop and metering)valve on it and everything worked good. It should be the only valve you need since it has the prop and metering valve in it. If the car has a prop valvre in the rear line under the car you could remove it if you put the combo valve in it. I got one of mine of a Duster at a junk yard and another of a disc/drum Duster my brother was parting out. Ron

Re: A Body disc brake swap - proportioning valve. [Re: VITC_GTX] #1412253 04/01/13 11:01 AM 04/01/13 11:01 AM
Joined: Nov 2003 Posts: 36,041 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,041 Lincoln Nebraska	Quote: I did remove the rear flex hose and blew compressed air through it. It seemed to have no restrictions at all. I'm wondering if my splitter/proportioning valve is where the blockage is Next step would be to unscrew the rear line male fitting from the splitter & hit the brake & see what you get for volume (It'd be good to have a piece of brake line to screw in the block to contain the mess into a jar). If restricted then unscrew & check the line in front of the splitter & if still bad that would point to the M/C half & if good there ahead of the splitter then there's a restriction in the splitter. Holler how it goes. I'm thinking M/C live every 24 hour block of time like it's your last day on earth

Re: A Body disc brake swap - proportioning valve. [Re: 383man] #1412254 04/01/13 11:04 AM 04/01/13 11:04 AM
Joined: Jan 2003 Posts: 43,603 Round Lake Beach, Illinoisy Rhinodart Rhinotruck
Rhinodart Rhinotruck Joined: Jan 2003 Posts: 43,603 Round Lake Beach, Illinoisy	On factory single piston disc brake set-ups there are two valves, the distribution block and a metering valve for the rear brakes. The metering valve is just downline of the distribution block. A lot of people just use an adjustable valve. Last edited by Rhinodart; 04/01/13 11:05 AM. The funny thing about science is that if you change one miniscule parameter you change the entire outcome to the way you want it. JB Rhinehart, Realist A-Body's RULE!

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