Hi! So even though my original heater core is not leaking, the nipples apparently are misshapen and causing leaks to occur into and outside of the car. Is there an easy way to bypass the heater core safely so that I can still run the engine until I have time to replace the heater core? This is a 72 350 with AC and auto trans. Thank you and sorry if this is a silly question.
Chris

 

Or maybe I should also ask if anyone has had any success in trying to reshape the nipples were the hoses attach? Thank you! Chris

 

I think reshaping those fittings would be better than replacing the heater core as finding a copper/brass core these days is not easy - most replacements are aluminum, and from my experience the aluminum ones had hose fittings installed incorrectly so it was impossible to fit them through the firewall and/or attach the hoses.

As for bypassing the core, you can get an adapter to allow connecting the 5/8" hose to the 3/4" hose (see link below). Alternatively, you can install a pipe plug on the intake manifold port and a cap or plug on the water pump port.

https://www.autozone.com/fittings-an...E&gclsrc=aw.ds

 

Thank you fun 71! I will try to reshape the nipples. If I am unsuccessful, I may try your pipe plug idea. Do you know what size pipe plugs I would need for the water pump and for the intake? Thank you!

 

A picture of what your looking at would help. The heater core takes 2 different size hoses, 5/8 and 3/4. If you use 3/4 on the 5/8 nipple and a stock spring clamp it will leak.

 

To answer the original question, just cap the two ports on the intake and water pump. That's all the factory did on heater delete cars.

 

Is the Redneck Solution to run a hose from the back of the block to the water pump port?

 

Joe, I saw a post you wrote from 2018 that says that you can put a pipe threaded cap on the intake but that won’t work on the water pump. May i trouble you to show a photo or a link of what exactly should be used for the water pump and the intake? Thank you!

 

I'd be lying if I said I'd never done that.

 

You can get the P.O.S. rubber caps sold by Dorman just about everywhere. Expect them to last 9-12 months before they crack and start leaking. I've been looking for a long time and finally found these reinforced silicone caps, which is all I use now.

https://hpsperformanceproducts.com/p...ete-black-blue

 

Okay perfect. I don’t have the car in front of me- it’s at the shop- but will this work for the manifold too? And do I use a hose clamp at the base of the cap? Thank you!

 

Those caps look awesome. Will definitely buy a few. What’s the OD of the water pump ports w/o me going out with a mic. 1/2”?

-peter

 

The line from the back of the intake to the heater core is 5/8" hose. The line from the heater core to the water pump is 3/4" hose.

 

So how do these attach? Hose clamp or do they compress around the ports? And can these also be used on the heater core nipples? Thank you!

 

Hose clamp, there is no need to put them on the heater core nipples.

 

^^^This.

 

@joe_padavano A follow up question to this old Thread. On my 72 Olds 350, AC has been removed and I want to permanently bypass the heater (don't drive it in cold weather and replaced the corroded heater valve twice in last few years).
In your opinion if I only drive this car Top Down in hot climate (80-110 degrees), is it better to cap the two ports like you mentioned above or use the Inline flow adapter with the small restrictor hole to keep water flow moving?
.

 

I got reinforced, silicone rubber caps on amazon.

 

You need the restrictor to protect the heater core. No heater core, no restrictor needed.


The crud in that heater valve says there’s an issue with your cooling system.

 

If you are not running a heater, simply cap or plug both ports where the heater would have connected. There is NO benefit to bypass flow on an Olds motor; in fact, by allowing bypass flow, you are reducing flow through the head on the passenger side, and the heads are the hottest part of the engine. Keep in mind that there is no bypass flow on the driver's side.

 

If you wanted to keep the heater hoses to look authentic, you could install a shutoff valve in the water pump and one in the manifold and connect the hoses to them and then close the valves and no water goes to the heater core. I did this on the 54 I had.

 

I guess I will have to shell out the $22 bucks then
.