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 Posted: 05-09-2006 02:40 pm
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Brett Gibson JH5 20497
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I'm having a problem getting heat into the car and have a couple of questions that hopefully some one can answer for me.

My plumbing is all hooked up and at one time I did have heat, but now I think my problem is in the two vacumn type valves, the water flow valve in the engine compartment, if I put vacumn on it, it will hold, and makes a noise like something is doing it's job, but if I drive the car with it disconnected, no heat, if I run a vacumn line to it from the manifold, and drive the car still no heat.

The little vacumn valve inside the car on the side of the heater box, how do you check it, am I correct in assuming that once the lever arm contacts it, that it sends vacumn to the water flow valve in the engine comp. or does it do something else.

So if my assumption is correct, and the little one provides vacumn, and when I drive with manifold vacumn on the flow valve and get nothing, then my problem is with the flow valve ???, so if I take it off, put a piece of pipe in and get heat, then it's definatly the flow valve, so what can be done to the flow valve to check or repair it, or is it a throw away and a call to Delta is in my future, or is it generic enough to pick up local.

Just one last thing, has anyone mounted that flow valve in a differant location than over the Jensen Healey name on the bottom valve cover, seem's a shame to block it off just for plumbing. 

Any and all suggestions would be greatly appreciated

Thanks.          Brett.

 

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 Posted: 05-10-2006 06:31 am
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Mark Rosenbaum
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Brett Gibson JH5 20497 wrote: [...] the water flow valve in the engine compartment, if I put vacumn on it, it will hold, and makes a noise like something is doing it's job, but if I drive the car with it disconnected, no heat, if I run a vacumn line to it from the manifold, and drive the car still no heat.
[...] when I drive with manifold vacumn on the flow valve and get nothing, then my problem is with the flow valve ???, so if I take it off, put a piece of pipe in and get heat, then it's definatly the flow valve, so what can be done to the flow valve to check or repair it, or is it a throw away and a call to Delta is in my future, or is it generic enough to pick up local.

Sounds defective to me.  Could be a plugged heater hose or heater core, though, or insufficient manifold vacuum.  Try removing the valve and testing it with a garden hose and a hand operated vacuum pump.  I don't believe the valve is repairable, so if spraying your favorite brand of penetrating oil on any potentially movable parts, inside and out, doesn't help, you'll probably have to replace it.  But check with Delta before tossing the old part, just in case there's a core charge or something of that nature. 

The little vacumn valve inside the car on the side of the heater box, how do you check it, am I correct in assuming that once the lever arm contacts it, that it sends vacumn to the water flow valve in the engine comp. or does it do something else.

This device is actually a vacuum switch.  When the cable-operated lever on the side of the heater presses the little plastic teat on the side, the switch will either either open ('pass vacuum') or shut (not 'pass vacuum'), don't recall which way it's supposed to work. 

Just one last thing, has anyone mounted that flow valve in a differant location than over the Jensen Healey name on the bottom valve cover, seem's a shame to block it off just for plumbing.

You should be able to move it anywhere you want as long as you keep it in the correct hose line.  Just make sure it won't hit anything when the engine torques or vibrates.

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 Posted: 05-10-2006 02:19 pm
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Brett Gibson JH5 20497
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Hey Thanks Mark................ couple of good ideas, I especialy like testing it with a garden hose, simple but effective, and yes, when it comes to a JH, I never toss things out, even if there busted, you just never know if you might have to salvage a bit here and there. 

As for the heater box vac switch I think I'll test that with a small vacumn pump I have to see if that holds, I would assume non-contacting the "teat" would be the closed position.

Brett.

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 Posted: 05-12-2006 12:29 pm
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Brett Gibson JH5 20497
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Mark,

As a follow up, I took the flow valve off last night and you can actualy see right thru the flow channel, so then I used a small hand vacumn pump and applied some vac to the port, and once I reached 7 "hg it started to turn the valve to block flow, at 10"hg the valve was completly closed.

So now I know how the flow valve works my next step will be to flush the heater core with fresh water and see if I get any grud out, and check the operation of the flaps on the heater box, maybe I'm getting cold air penetration, I dont have rust issues on the box, and I replaced all the seal's during the restore so maybe a flap has become misaligned ???

Thanks again for your idea's

                       Brett.

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 Posted: 05-12-2006 09:56 pm
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edward_davis
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I'm also getting very little heat from my heater core, but that's not as big a problem here in CA.  My problem is that I have had a long-term coolant leak from the heater core, but I only recently realized that's what it was.  The carpet pad under the console is sodden, and over time small amounts of coolant dribbled onto the driver's side rubber floormat.  I always thought it was just a small amount of water or oil I tracked in on my shoes. 

If I put the heater controls over on "cold" that should send vacuum to the valve you checked, right, Brett?  So there won't be any flow into the heater core, and I shouldn't have any leak.  Does anybody know if there's an easy way to just bypass the heater for the time being? 

How much does a new/ rebuilt heater core cost?

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 Posted: 05-12-2006 10:09 pm
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John Finch
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You could splice the heater core supply and discharge hoses together using  hose barbs and hose clamps. Hardware stores might have brass or stainless double male ends. Not sure of the size required. You could always cut a small portion, say 1", off the longest hose and take it with you. Just remove the existing hoses from the firewall male fittings and splice them together. Completely bypasses the heater core.

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 Posted: 05-12-2006 10:17 pm
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John Finch
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Putting the selector on cold closes the valve. But its on the discharge side of the heater core IIRC. So this means (hot) coolant is likely in the heater core up to the valve. It is not circulating but is under pressure so will find the hole in your core. Only solution I can think of is to repair the core or bypass it (as above) until you choose to.

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 Posted: 05-15-2006 11:48 am
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Brett Gibson JH5 20497
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Ed,

John's right, just having the flow valve closed does'nt take away coolent pressure on the system, it just stops the flow, but if you have a leak the flow will be going thru the leak, best bet and simplest is as John said just bypass the heater core, I would blow out any remaining coolent out of the core so that you dont get that draining off into your car though, also the hose looks to be standard 5/8" heater hose. 

Good luck

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