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MGB MGB heater flow or lack of

Norton47

Jedi Warrior
Offline
Hi
I got my heater re-installed after having the heater core boiled out and rodded. I got the new rubber seal installed, the control cable hooked back up and was expecting heat on demand.
After warming up the car, I have nice air flow that is controllable to the defroster or to the interior or off and no heat.
The hose to the heater is warm but the hose coming from the heater is not. So, I pulled off the hose from the heater control valve and no water flow.
OK, I think the control valve is gunked up, it's 37 years old, no sweat.
I pulled off the control valve and it looks great, I can blow through it, close it and it stops flow. So now what. I took a deep breath and blew into the hose going to the heater and water blew out of the block where the heater control valve had been installed. I think this means that there aren't any blockages in the whole circuit.
So what's up with this thing??
Is the water pump shot? I haven't seen any signs of overheating. Today in running it to check the heater it sat there and ran, as the temp gauge came up, the thermostat opened, I saw some flow (nothing to rapid) in the radiator as I had the cap off and the water got hotter, the gauge never indicated overheat, and it dropped slightly after the stat opened, so that all seems to be working.
But there isn't any real pressure in the hoses. When I pulled the hose, the water didn't really flow just seemed to rise up in the hose like it was equalizing with the rest of the system water level.
How would one check to see what flow rate the pump is pumping at? What else should I check?
Thanks
 
Hmm... he said he has an OEM Smiths heater valve; it should not need shims.
 
Saw that scott. He either screwed that up or the OEM sucks just as bad as the junk chinese one's we are paying 20 bucks for. I bought a new one and took it apart also. Tons of flow on mine, fwiw.
 
Thanks for the links.
I took the valve off and replaced it with one from my spare parts car. a 1974 MGB, it appeared to open and close and let water through on the bench. Now installed and adjusted and I have heat.
Have to look at reworking the other one and have it as a spare.
Thanks again.
 
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