driving the 83 D-150,, it seemed like it just did not want to move away from a stop, I jacked the truck up, set it on jack stands, applied the brake, released then tried to spin the tires,, the rear was fine,, the fronts were not.

for the front, it would take 28 seconds from the time the brake pedal was released before I could just move the brake disk with hand power. It would take 45 seconds before one could get the disk to spin freely..

In rebuilding the truck I had put on a lot of new brake parts, new master cylinder, new brake booster, new brake lines, used existing calipers and proportioning valve.

figured the calipers were old, sticking so replaced those, if anything the front brakes stuck on harder.. One by one I re installed the OE master cylinder, brake booster,,, no change,, verified the brake lines were open...

that left only the proportioning valve,
per my 82-83 part number manual,
4131280 D,W2-3-4 Valve metering and warning
4131281 A,D,W1-2-3 Valve metering and warning

this is from my 82-83 Mopar Parts book
the way I read it,
the 4131280 D,W2-3-4 would fit all 2 wheel D series and 4 wheel 250,350 and 450
the 4131281 A,D,W1-2-3 would fit all A series (?), all 2 wheel D series and 4 wheel 150,250,350

Called the local dodge parts desk, they said the 4131280 has been replaced by a 4293184
the Dodge dealer said his book which only goes back to 1984 says:
4131280 (4291384) is used on 84 to 93 Ram Truck and Van
4132181 is used on 86-93 Ram Truck and Van

I ordered the 4291384,,
installed it, bled the brakes....
success, the front calipers release as soon as the pedal is released.
Took the D-150 on a short drive through the neighboorhood.
stopped fine on both normal and a few slow speed hard stops.

here are photos, the old valve is the top one , I took the front end apart, there was a lot of varnish / residue on the spring and in the chamber.

http://www.flickr.com/photos/13718356@N ... 878748723/

Thank you ! This is great information.

A series is the Ramcharger.

thanks, I was suprised to,, I knew the proportioning valve delays pressure to the front disks slightly so the rear shoes have time to contact the drums,,in resolving the problem I did not consider the proportioning valve was reacting slow..until it was the only thing left,,,

Technically the valve you took apart in the front circuit is the metering valve- the proportioning valve is in the rear circuit. I've seen lots of different things cause brake drag before, that's the first time the problem was a "combination valve." Live & learn.

For future reference, any time I see a drag problem I crack a bleeder to see if the problem is hydraulic or mechanical. If the bleeder helps then I pump up the pedal again & try the next line fitting that's closer to the master cylinder- one at a time- until I find the culprit.

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63 Valiant Wagon
225 - 4 bbl