bigvette1

I have a 73 BB with AC. The heater core has started leaking, not so lucky that it is not a loose hose at the core connections.

Need some advice and maybe some clarification. If I install a blocking valve in the either the 5/8" or the 3/4" hose does that not still allow coolant to flow into the heater core and with a leak it will still leak. Is this not what happens?

If so, what is the best way to bypass the heater core completely until I can go to removing the core and replacing it?

garygnu

you can remove the fittings from the water pump and the intake the hoses connect to ,and plug them with threaded plugs.

bigvette1

Just a thought -- would it be any better to route the water pump hose to the intake manifold hose so there there is still flow between the pump and the intake?

Peterbuilt

Plugs or bypass manifold to water pump is OK but your stretching the 5/8 hose so remember it's just a temporary fix>

andy67

my heater core has a pin hole leak so i took both lines off the core and joined them together with a 1/2 by 3/4 copper coupling and two hose clamps primitive but works and made no difference in temp

bigvette1

Thx for the answers and plugs it is. Tried the search function and could not get the desired responses. Try again.

Chinaski

I just used brass pipe plugs from the Hardware store and plugged the water pump and intake manifold...I removed the hoses from the heater core all together. Remember, NPT pipe plugs are tapered so DON'T overtighten them. Just use some teflon and make them snug.

Paul L

Yes, you are putting a 5/8" hose on a 3/4" fitting but as you say it is a good (and inexpensive) fix until the leaky heater core is taken care of. I drove about three weeks in that condition. Worked fine.