View Full Version : Heater hoses

Project GatTagO
12-03-2004, 10:16 PM
I am trying to get some heat in my RX7. There are 2 fitting on the side of the water pump for the heater hoses. One is large the other is smaller.

Which one goes TO the heater core and which is the return?



12-03-2004, 10:49 PM
I thought they both went to the heater core; I will look tomorrow.

5.3 racer
12-04-2004, 07:10 AM
5/8 goes TO the heater, the 3/4 is the return.

12-05-2004, 12:23 AM
5/8 goes TO the heater, the 3/4 is the return.

not sure the flow direction but regardless have them both hooked up

Project GatTagO
12-05-2004, 09:20 AM
I understand both go to the heater core. I need to know what is the pressure side and what is the return.

Thanks 5.3!Andrew

12-05-2004, 12:53 PM
Yes, the front (larger fitting) is the return. In fact, on my 5.3 Envoy they take the cylinder head purge line directly into the larger heater hose. That might be a handy tip for those trying to figure out what to do with the purge line when you don't have the extra nipple on your radiator.
The black hose you see here is the cylinder head purge line teeing into the heater hose.

Project GatTagO
12-06-2004, 08:21 AM

Thank you SO much. That is exactly the information I was looking for. I am installing a remote radiator filler in my RX7 and I needed to run a hose from the filler to the sucksion side of the water pump. Now I have my spot!

Thanks again!