The Stovebolt Site Forums The Shop Area Interiors Fresh air heater control valve rebuild

I need to get my valve rebuilt, who is the best vender for this service?

Probably the guy that's looking back at you in the mirror. There isn't much to the rebulding and the part is avalable at most of the auto parts stores.
Take a look at the procedure here: http://www.pbase.com/dennygraham/ranco_hf_br&page=1
Denny Graham
Sandwich, IL

Denny,
I was thinking of sending mine in to get rebuilt, but looking at your step by step procedure Pics, I am inspired to rebuild it myself! Thanks again for submitting Clear and Focused Pictures.

Denny, Thanks for the info and pics. I am concerned with breaking the little tabs or messing something up.

I've worked on all kinds of truck and car parts surprising myself with what I can learn to do. It always seems to be: getting help from others who have been there. Then there's keeping the brain engaged so as not to go too far too fast and wishing I had taken more time or asked for help first.

Denny,

Sure enough the local NAPA store had the part. Using the great pictures I completed the rebuild. I wanted to confirm operation of the unit, manually it workd fine. I tried heating the cap-tube in a pan of hot water to verify operation, nothing happened. The tube and button-bellows look just fine. Do you know how to bench test this baby?

Don

With it out in the open at room temperature it's going to be closed. Put it in the freezer and leave it for a good 15 minutes and if it's good the diaphragm should shrink up and open the valve. Remember this is supposed to call for heat or water flow when the truck is cold. You may have to play with the bias spring adjustment to get it dialed in where you want it. I don't know of any procedure for calibrationg them. These Ranco control valves are marginal at their best so don't expect to have as much temperature control as your new Silverado.
Denny Graham
Sandwich, IL

For those of you that have rebuilt the valve by replacing the rubber seal, I'm just curious if it worked for you, did it hold pressure, or does it leak? I have my valve dismantled and am about to install the new seal. Any comments would be appreciated. Thanks.

Dale

Dale, here are some pictures of the Ranco rebuild. The rubber seal shouldn’t leak at all, that’s the object of rebuilding it. The valve itself does not close off all of the water flow some will leak by so you will have a small amount of circulation.
http://www.pbase.com/dennygraham/ranco_hf_br&page=all
Denny Graham
Sandwich, IL

replacing the seal works, providing that shaft is where the leak was - there are other spots the control may leak

Bill

Denny--Thanks for posting all of those great pictures, I printed them for reference awhile back, before I dismantled my valve. I know the new seal shouldn't leak, but sometimes things don't do what they should! A number of people have rebuilt their valves but I don't remember anyone saying how it turned out, after it was in operation in their truck. Did yours work OK?
Bill--So your seal didn't leak?
One more question: The neck of the rubber seal has a little piece of wire wrapped around it. Did you have to pinch that a little to tighten it, or just leave it alone? Thanks.

Dale

No I did not have to tighten up the wire to get the shaft to seal. Of course the plunger has to be clean without scratches or pits, I did use a little rod wax on the shaft (Vaseline). If the diaphragm or capillary tube had a leak then the thermostatic control is not going to work. It’s filled with a fluid (unknown) and cannot be refilled or recharged. You can test it by placing it in the freezer and giving it about 15 minutes, it should collapse if it doesn't then you have a leaker. You will have to play with the adjustment of the cam to get the best operation when you turn the heat control.
As far as how well it works, I’d say that it does stop most of the water flow. But as I said the internal valves don't seal all of the water from circulating and a little will leak thru even when fully closed. It does seem to control the heat to some degree but it has a very slow response. Because there is still a little water flow when the temp control is turned of a shutoff was often place in one of the lines for summer use. The vendors sell several types of shutoffs, one is screwed into the water pump and others are inserted into the heater hose and can be controlled by a cable.
Don't expect it to control the heat like you 2010 Chevy truck.
Denny Graham
Sandwich, IL

I REBUILT MINE and it pressure tested perfect. I haven't tested it in the truck but I don't anticipate any problems...

Hey guys:
Great info, I have a 54 3100 with the air flow heater/defroster...I don't have the inside control rod that opens & closes the ranco valve. Does anyone have a lead on that rod and dash mount ? and a on-line 54 Chevy Accessories Installation Manual. So I can see in detail the set up.
Thanks