capping off heater hoses

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martin53

martin53
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I have a 1973 318 and was wondering how do I cap off the heater lines from the engine. Ones on the intake manifold and the other is on the water pump.
 
Best way is with a threaded plug but installing one in the aluminum water pump is nearly impossible without cracking it . Don't trust those rubber boots that plug the end and are held on with a hose clamp for anything more than a temporary fix. There are water pumps available that have a threaded bore for the heater hose nipple so they are easy to plug off but they're quit a bit more than a stock replacement w/p . I believe they're made by edelbrock.
 
I have dun this and just looped the two lines together, I am sure a Good experienced Tech will chime in soon enough, I was concerned about flow of coolant being stopped to go some where ells, so that is what I did.
 
I have a plug for the intake. And a rubber plug for water pump. But as mentioned before they suck. They dry out quick and leak. Tapping for plug is tricky. Not a lot of meat in the pump.
 
Whatever you do, don't put those rubber caps on them, because they will leave you stranded and overheating in a week.

Cap them with threaded plugs and use teflon tape on the threads.
This is absolutely the best way.
 
martin53 said:
How would I cap the one on the water pump it has no theads
Click to expand...

You'll have to tap it - cut threads. I wouldn't attempt it with he water pump installed. I did one years ago and wound up fracturing off the nipple for the heater hose. I cut it off flush and cut the threads for the plug in the body of the water pump.
 
If it's just for summer because you want to keep heat out of the heater, then just make a shorter loop and bypass the core.
 
im watching this as i need caps for the slant pump... maybe drain out the coolant and clean the nipples, then epoxy the holes up or tig a cap on them?
 
I took a short piece of heater hose(2-3 inchs) , clamped to the fitting then stuck a unilug lug nut (for 1/2 studs)in the other end of the heater hose and put a hose clamp on that. Ran the car like that for 2 years, never had a problem.
 
I ran the rubber plug for 2 years and I replaced the plug at least 5 times. You can find the plugs in an assortment package in the "Help" section at Autozone, and the package comes with 2 in that size. Keep the other in the glove box with a clamp for a spare.

Over the winter I tried tapping the water pump for a plug and cracked it so I had to buy another. I got it on the 2nd try but I was nervous. As mentioned before there isn't much meat to it.
 
I've tapped several pumps to accept a 1/4" pipe plug but you gotta go slow and easy. Tap too fast and the aluminum will ball up and split the nipple. You also need to do it with the pump removed of shavings will drop down in it. After I install the pipe plug (use some pipe sealer on it) I slip one of the rubber plugs over it to clean it up. That's all those plugs are good for. Too thin to last under pressure.
 
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