Bypassing heater system entirely

[jmcm]

Hi Guys

Removed the radiator last night to take to a radiator shop and noticed that my heater pipe ('84 w/ AC version) is totally corroded and leaking particulate rust.

A while back I bypassed the heater inside the firewall with a single coolant line running from one side of the engine (to heater, now bypassed) to the other (into the engine, from the now bypassed heater).

Can I replace this corroded piece of pipe with a piece of straight pipe - this would not include a port to send hot coolant to the heater - and bypass the entire coolant system, plugging the "into engine" port?

I can upload photos tonight.

 

[reddingcruiser]

You don't need heat for your feet or your defrosters, you don't 'need' any part of the heater system. Some imports didn't come with any heater units at all. Block it off or loop it. Use heater hose or corrosion resistant tubing/pipe where you need to.

 

[jmcm]

Thanks reddingcruiser, that's true.

Mostly I'm concerned about the engine inlet line. Does the engine need to receive coolant in the rear upper LH side to function properly? Would I be risking damage to the engine if I don't send any coolant to the heater line / engine inlet line? Besides the large-diameter inlet/outlet from the radiator to the engine?

Didn't get to pictures tonight, will post in the morning for clarity.

 

[73FJ40]

Flow for the heater system comes OUT of the top of the head at the rear left port, and returns to the coolant system at a tee in the middle of the lower radiator hose, which supplies "cooled" coolant from the radiator to the suction of the water pump.

There is no need for any flow through the heater system for normal engine cooling purposes.

The "quick" way to bypass the heater system is to run a hose from the head to the lower hose connection. However, this allows hot coolant to bypass the radiator.

Alternatively, you could plug the head with a 1/2" BSPT (BRITISH PIPE THREAD - tapered) plug and cap off the connection on the lower hose. Additionally, I believe that a one piece lower hose might be available to eliminate the Tee in the hose entirely.

 

[jmcm]

Thank you! This is what I was hoping to understand.

So the flow is from the top of the engine. Any issue with using a brass BSPT plug in terms of metallurgy? I assume I'll want to put a hot service teflon tape to lubricate the threads for future work.

That radiator hose looks pretty corroded, so I think I'll take you up on that last concept.

 

[73FJ40]

Any issue with using a brass BSPT plug in terms of metallurgy?

That radiator hose looks pretty corroded, so I think I'll take you up on that last concept.

Brass is better than steel from a corrosion standpoint, just be certain to use teflon or some other sealant to avoid corrosion.

Remember, the pressure in the coolant system is less than 15 psig, so don't use a lot of force to tighten the plug.