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Topic: Gate Valve to stop hot coolant from flowing to dash heater (Read 753 times) previous topic - next topic
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Gate Valve to stop hot coolant from flowing to dash heater

Yahoo Message Number: 78917
Originally, my rig had a Gate Valve installed below the engine on the coolant line running forward to dash area.
When the rear school bus coolant pump failed and leaked, I had both the pump and the gate valve removed. (The pump and its front mounted twin could not be shut off with the ignition on and it appeared that the pump would be destroying itself trying to pump coolant from a closed gate valve.)
I still get heat from the dash heater when needed and hot water at the end of a day's driving.
Has anyone used their installed gate valve to improve the cooling from the dash AC by restricting the hot coolant flow to the front of the coach?

If so, was the improvement significant?

Thanks for any insights
Dean

95 Magna 5280

Re: Gate Valve to stop hot coolant from flowing to dash heater

Reply #1 –
Yahoo Message Number: 78919
Dean,

From your description, it sounds like you have a "Motor Aid" water heater with an internal heat exchanger that borrows heat from the engine coolant. I had one of those on a previous coach. The cheap gate valve failed and caused loss of coolant which lead to catastrophic engine overheating and failure. All this on a narrow mountain road with very narrow turn outs and a 8% grade!...But, that is another story.
Does that same line serve your dash heater? How does the coolant circulate without a booster pump? is there another booster for the dash heater? Daron Hairabedian, 98 Allure 30226

Re: Gate Valve to stop hot coolant from flowing to dash heater

Reply #2 –
Yahoo Message Number: 78936
Daron, there were two school bus pumps installed after the gate valve. One next to the valve and one behind the front bumper. I removed the rear pump after two on the road failures. The front pump just sits there. I never tried using the gate valve.
The coolant still moves to the front and ultimately heats the water heater tank.
Just wondering if stopping the hot coolant flow to the front using the gate valve makes much difference in AC cooling.

Dean

95 Magna 5280

Re: Gate Valve to stop hot coolant from flowing to dash heater

Reply #3 –
Yahoo Message Number: 78938
Dean,

There should be a hot water shut off valve on the heater/ac unit that shuts off the hot water when ac is on. You can test by getting access and cycling the ac and heater to feel what is going on.

Leonard

Re: Gate Valve to stop hot coolant from flowing to dash heater

Reply #4 –
Yahoo Message Number: 78940
Hi Friend, On our 99 Allure I installed two Brass Ball Valves at the engine to valve out the dash heater supply and return if the pump Fails or the heater core etc. leaks. Also I connected a switch to turn off the cir. 12 vdc pump. After driving for several hours I still get heat with the pump turned off. Working on Diesel generators in my other life my Enging Block heaters always had Ball valves so the heaters can be replaced without draining coolant. Old habit to break. My 2 cents. Also the dash A/C seems to run cooler with the pump turned off as I have a Temp Ga. clipped to one of the outlet vents. Our older Allures have a cold air problem with dash airs. Ken Retired Cat Power System Tech. 99 Allure 30356
 

Re: Gate Valve to stop hot coolant from flowing to dash heater

Reply #5 –
Yahoo Message Number: 78970
I have simply pulled wires to to the circ pumps to the dash heater at the fuse. I can still bake my ass off without those running,

Rich 2002 Magna