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Flushing heater core

pekkerwood

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Mar 10, 2018
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australia
hello everyone

I’m fitting a new radiator to my 80 series HD-ft.

I am contemplating blowing compressed air into the inlet hose of the heater at the firewall and disconnecting the outlet hose at the fire wall and add a extension so it doesn’t make a mess.

Will this work to get the old coolant out, and could someone post a picture of where to connect the air compressor hose

Thanks
 
Hello and welcome. I'm not too sure of the heater hose locations, but you might be better off reverse flushing with water. If there is any build up of deposits in the heater matrix, something might give if using air pressure.
 
Thanks mate, I was going to do that. I live in Adelaide Australia and we have the worst tap water on the planet bar some of the third world countries so I would like to get the tap water out before refilling. I guess I could get a submersible pump and flush with distilled water, or maybe just not be so pentantic about it and get on with it

Thanks
 
I think that honestly this is an unnecessary step. I'd just drain the engine as per normal and fill it up again. Do it with the heater set to hot and it might pull some of it through. There's little in there to worry about. Once you refill and run it, what little is left will be hugely diluted.
 
One problem that comes up sometimes is the heater matrix getting clogged up with deposits in hard water areas causing the heater to under perform. If there's no problem with this, then as Chris says, not worth the bother.
 
thanks mate, that’s exactly what I will do. I will buy coolant as concentrate and add it to a ratio for twelve litres and what ever distilled water it takes to fill the system minus what’s left in the core so be it

Thanks
 
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I haven’t pulled it apart yet, so if the heat is cranking warm then all good to go

Thanks
 
Sometime the heater needs to self bleed a little when you do a full drain and refill. DOn't panic if it doesn't get hot straight away. Just leave the slider on hot. Does it also have a rear heater? That's full of water too.
 
Yes it has the rear heater as well, so you mean run the heaters and keep topping up the radiator as needed for a while

Thanks
 
I don't think the concentration is critical. I err on safe side and put "too much". I take mine for a drive to get everything up to temperature after initial filling with engine idling after most of the volume has gone in. Let system cool overnight then top up and that's always been OK.
 
When I lived in Canada, reverse flushing was a so-so mediocre repair. Tanking the heater core (or rad core) was next best. But the best "repair" was replacing the core with new. Expensive, but it resulted in lots of heat from the heater and proper engine cooling with a new rad.

Don't be cheap - replace the hoses and hose clamps too. Also anti-freeze has rust inhibitor thst lasts maybe 5 years. Replace it. More often with hard/bore water.

Obviously you, the reader, can do as you wish. However, how much is your time and the PITA and the uncertainty factor gonna cost you? You have to decide what - among the limited options - is best for you and your situation.
 
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Yeah mate it’s a new radiator going in. Old hoses are swollen at the clamp, so they will be new.
I’m at the extreme end of servicing my Toyota I don’t have grog or smokes can’t find a woman that what’s to clean my Toyota so plenty of disposable money for servicing.
 
There’s always Toyota Red coolant. It’s pre mixed and arguably the best thing for your engine. Not cheap but it’s good stuff. It’s got a few mentions on here if you do a search.
 
The coolant isn’t big bucks to be fair but it has lots of fans in cruiserworld. :)
 
My mate has a 2006 Toyota 78 series, we changed the diff oil used Penrite oil with the specification listed in the manual 85/90 LSD.

The diff started to play up around corners had us baffled went to all the gurus they couldn’t find anything.

Thought it’s a long shot but let’s drain the diff and put Toyota oil in, problem solved.

I know Toyota don’t make there own oil they rebrand someone’s product but maybe they add something.

So it’s original Toyota where ever possible for me, I didn’t buy a overpriced Japanese car to convert it to a cheap Chinese car.
 
what I’m trying to do is get rid off every last drop and start fresh with the new radiator, but as most of the learnedly colleges say on here don’t get to stressed over it as what residue is left is insignificant if using the same coolant.

Thanks
 
Whilst it is common knowledge that the heater control should be on hot when filling to get the air out, something that is not obvious is that the heater slider will move from left to right but, this will NOT operate the heater valve, the cable is driven by an electric servo/motor.

So engine on, heater/slider to hot, then switch engine off, heater valve will remain open, fill slowly and air will be pushed out so need to worry about bleeding.

Regards

Dave
 
Whilst it is common knowledge that the heater control should be on hot when filling to get the air out, something that is not obvious is that the heater slider will move from left to right but, this will NOT operate the heater valve, the cable is driven by an electric servo/motor.

So engine on, heater/slider to hot, then switch engine off, heater valve will remain open, fill slowly and air will be pushed out so need to worry about bleeding.

Regards

Dave

All you guys with your posh 80s. The slider cable on my HZ goes directly to a manual tap/valve on the bulkhead, open is open, closed is closed, job done :lol:.
 
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