75 FJ40 overheating

[bugman]

Recently replaced the waterpump and fan, ran great. The heater never worked and there wasn't a rear heater. I got a rear heater and hooked it up (removed the crossing hose someone had used to bypass) and now the car overheats. Do I need to clean out the heater core or replace the thermostat? Has someone seen this before?
gene

 

[Joe Egolf]

I'd say clean the heater core ,ie thats why it never worked. My heater worked sorta , and when I back washed it I could not believe how so much crud was in there. So I am guessing when you hooked up the heater you blocked the coolant circulation?

 

[bugman]

I'd say clean the heater core ,ie thats why it never worked. My heater worked sorta , and when I back washed it I could not believe how so much crud was in there. So I am guessing when you hooked up the heater you blocked the coolant circulation?

No I had put water in to work on it and let it run out till I got the hoses hooked up. There was some 'gunk' which came out when I pulled the connector hose off. Thanks for the reply. Gene

 

[bugman]

No I had put water in to work on it and let it run out till I got the hoses hooked up. There was some 'gunk' which came out when I pulled the connector hose off. Thanks for the reply. Gene

I pulled the heater and flushed out the core with muratic acid, there was alot of gunk in it. At first I couldn't put the hose on one end and have water come out the other but with a few flushes it flows good now. I also connected the inlet and outlet from the heater together and the FJ doesn't overheat. So I think I'm there. With that problem at least. What does that little valve connected to the "warm pull" do? Gene