heater hoses

moose · August 03, 2006, 05:05:31 PM

I want to install a manual shut off valve in my heater hose. Is it better to install it on the pressure line from the pump or the return line to th emanifold or doesa it matter?

Tim

donsrods · August 03, 2006, 05:25:01 PM

I think on the pump side. Otherwise hot water will still be in the heater core, warming up the cockpit on Summer days, plus, if you sprung a leak in the core the valve would have shut off the water before the heater.

I don't know if that seems logical, but I think it is the way I would do it.

Don

EMSjunkie · August 03, 2006, 06:26:40 PM

I agree with Don, I would put it on the pressure side.
that way you can isolate the heater core when you don't need it.

just my non-sensical ravings of my lunatic mind.

Vance

moose · August 03, 2006, 06:54:51 PM

Thanks guys,

That was my thinking as well. Just couldn't remember for that rthe pump was the pressure side for the heater.

Old age setting in early !

Tim

Ed ke6bnl · August 04, 2006, 03:22:55 AM

Quote from: "moose"I want to install a manual shut off valve in my heater hose. Is it better to install it on the pressure line from the pump or the return line to th emanifold or doesa it matter?

Tim

My boy and i put in a ford truck manual heater valve and then added a old jeep cherokee door lock mechanism to turn it on and off from the driver seat. can be used just as a manual on off switch. ED ke6bnl

EMSjunkie · August 04, 2006, 05:06:58 PM

Quote from: "moose"Thanks guys,

That was my thinking as well. Just couldn't remember for that rthe pump was the pressure side for the heater.

Old age setting in early !

Tim

I can empathize with the old age thing

the pressure side is the side that comes off the intake, the return goes to the water pump.

Vance

DrJ · August 08, 2006, 02:14:47 AM

Don't confuse direction of flow with pressure.
You are going to have pressure all over the closed pressiurized system, and a leak will leak no matter which hose it's in.
If you stop the flow from either end, the hot coolant won't flow to or through the core.

donsrods · August 08, 2006, 02:26:15 AM

If you stop the flow from either end, the hot coolant won't flow to or through the core.

Sure it will. If you stop the flow after the core there will always be water in the core, and as the water temp in the block heats up it will for sure heat up the water trapped in the hose. It doesn't have to be moving to pick up that engine heat, just being connected to it will make it hot.

My thinking on stopping the flow before the core is that the hose is less likely to spring a leak than the heater core, and also, when that core heats up (through induction....even if the valve is shut off after the core) the cockpit will be getting that unwanted heat.

If you think this doesn't happen, feel the heater hose in your own car when the valve is shut off, but the engine has been running for awhile. The hose that is leading to the valve will be hot and the other hose will be cool.

Don

DrJ · August 08, 2006, 12:57:33 PM

Quote from: "donsrods"...If you stop the flow after the core there will always be water in the core, ...

There IS always water/coolant in the core, it just isn't circulating with the valve shut.

Quote
...and as the water temp in the block heats up it will for sure heat up the water trapped in the hose. It doesn't have to be moving to pick up that engine heat, just being connected to it will make it hot....

True, convection currents would warm the water over time but not as fast as it would radiate through the hose and core. It would be warmer than ambient air but not as hot as the engine.

Quote
My thinking on stopping the flow before the core is that the hose is less likely to spring a leak than the heater core, and also, when that core heats up (through induction....even if the valve is shut off after the core) the cockpit will be getting that unwanted heat.

Try it out...shut your heater valve and disconnect a heater hose "behind" it.
If you're right, nothing will come out of it. Right?
(Any opening in the system will leak, profusely if there's heat pressure.)

Quote
If you think this doesn't happen, feel the heater hose in your own car when the valve is shut off, but the engine has been running for awhile. The hose that is leading to the valve will be hot and the other hose will be cool.

Don

It may be relatively cooler depending on how far the valve is from the engine and whether it was shut all the time the engine was heating up or if it was shut off after getting hot.
A heater core is just a small radiator.

It is designed to allow heat from the coolant heated metal to pass to the air passing through it. The air cools the core just like it does the radiator up front. if there's no coolant flow, the core doesn't get heated again, other than a very small amount from convection currents.

moose · August 08, 2006, 12:57:53 PM

My reason for wanting to install a shut off valve is as stated. I want to remove or minimize the static heat in the heater core when not wanted. I eventually plan to switch out the old evaporator unit for a Vintage Air unit. At that time I use their electric valve. In the meantime I want to remove the flow to the heater core when not wanted. I already have a manual valve and if the one isn't enough I will pick up another and seal both lines...

Tim

DrJ · August 08, 2006, 01:28:13 PM

Just use one valve, fewer parts to leak, (and I have seeping valves on two vehicles right now) . Put it in the "intake" side if possible, as has been suggested, BUT,if it's more convenient or only possible, or neater to put it in the outlet, it will still do the job just fine.

donsrods · August 08, 2006, 02:02:12 PM

I'm just a simple country boy, but it just seem to me that the BEST place to install the valve is before the core. Every factory car I've owned has been done this way, so I guess they have a lot of country boys up there in Detroit, too.

But, in a pinch, you could put it after the core.

on

DrJ · August 08, 2006, 02:35:40 PM

Quote from: "donsrods"I'm just a simple country boy, but it just seem to me that the BEST place to install the valve is before the core. Every factory car I've owned has been done this way, so I guess they have a lot of country boys up there in Detroit, too.

But, in a pinch, you could put it after the core.

on

That's right.
It is the best place, but doesn't have to be the only choice, and neither place will keep the stinky hot green slime off your girl's toes if the core springs a leak.

Also
I wouldn't put something like a 18 pound pressure cap on a system that's using an old heater core that was made for a car that didn't run any radiator pressure at all.
I run a 7 pound cap because that's the lowest I can find that works with a coolant recovery system, and so far my 1939 Chevrolet Deluxe Heater hasn't complained.

And I learned most everything I know about cars from my Dad and he learned it on the farm in Texas..

Well him and "a few" classes at the local GM service training center.

donsrods · August 08, 2006, 02:53:34 PM

and neither place will keep the stinky hot green slime off your girl's toes if the core springs a leak

Hey, she's my "early warining system." When she starts yelling, I know my carpet is about to get ruined with anti-freeze. See, I really am a man who thinks about my women.

Don