Sherwood heater question

**123rover50** · 12th January 2014, 06:23 PM

Originally Posted by Blknight.aus

before you go that far...

try putting a longer hose on the heater matrix with a very thin one on the inside (a bit of 6mm id aquarium hose works well)

use a small unwatned pond style pump to move cooling system flushing agent up the smaller diameter hose and into the heater matrix using the larger hose (go up and over the wing) to return it to the bucket (strain through an old sieve)

keep the rest of the cooling system connected together and run a return line from the fitting you pulled the heater hose off of from the block to also return to the bucket BUT dont run it over the wing drop it down from the inside the engine bay so that once the heater starts to flow it will continue to do so through the block.

once you have some movement there keep using the pump but fill from the larger hose not the aquarium pipe.

it might take a night it'll probably take a week but eventually the coolant flush will shift the rust and gunk thats holding up the works

now go and do a proper flush on the system being wary that the heater matrix may have been weakened. do a pressure test and then flush and refill

I eventually got the heater out anyway. Black gooey stuff is leaking from the pipes. I dont think I should put it back rodded or not. To be safe would not a new core be better. I would hate to go through this again and I am still pulling it to bits as I still have to work out how to split the case.

**123rover50** · 12th January 2014, 06:26 PM

Originally Posted by pop058

I have just found this thread

WOT HAVE YOU DONE ??

Sorry.
It gets worse

**Dougal** · 12th January 2014, 06:41 PM

Originally Posted by 123rover50

I eventually got the heater out anyway. Black gooey stuff is leaking from the pipes. I dont think I should put it back rodded or not. To be safe would not a new core be better. I would hate to go through this again and I am still pulling it to bits as I still have to work out how to split the case.

If it's rodded then flushed clean and pressure tests to a good safety margin (say 30+psi, working pressure is 15psi) then no reason not to use it.

A bigger question is where the black gooey stuff came from?

**bee utey** · 12th January 2014, 06:51 PM

It sounds like someone changed the coolant without flushing the old coolant out of the heater core. I had something similar happen some years ago (not flushing properly for a coolant change) and the vehicle's radiator was almost 100% blocked with gunge within 15 minutes. Unless the heater core had been promptly back flushed it would stay blocked.

**pop058** · 12th January 2014, 06:58 PM

Originally Posted by 123rover50

Sorry.
It gets worse

All good, at least it is in good hands

**123rover50** · 12th January 2014, 07:51 PM

The heater and aircon have never worked since my wife bought it 15 odd years ago. Living in Qld it was never a problem untill this hot spell when she said it would be good to have aircon.
No refrigerant in it so took it to the local leccy to get leak tested. Pumped some nitrogen into it when BANG the suction hose went.
If it wasnt leaking before it is now.

So my troubles started

**123rover50** · 12th January 2014, 07:55 PM

Originally Posted by bee utey

It sounds like someone changed the coolant without flushing the old coolant out of the heater core. I had something similar happen some years ago (not flushing properly for a coolant change) and the vehicle's radiator was almost 100% blocked with gunge within 15 minutes. Unless the heater core had been promptly back flushed it would stay blocked.

Being constant circulation would it not have kept clear or are the passages so small they block anyway.
I guess the latter.

**Blknight.aus** · 12th January 2014, 08:01 PM

Originally Posted by 123rover50

I eventually got the heater out anyway. Black gooey stuff is leaking from the pipes. I dont think I should put it back rodded or not. To be safe would not a new core be better. I would hate to go through this again and I am still pulling it to bits as I still have to work out how to split the case.

thats what happens when you put the early versions of bars leak into a system, it blocks the small galleries especially when it sits for a long time...

I'll back Dougals opinion but given how gooped it is it might just be quicker and easier to buy one outright.

**bee utey** · 12th January 2014, 08:10 PM

Originally Posted by 123rover50

Being constant circulation would it not have kept clear or are the passages so small they block anyway.
I guess the latter.

When I say the rad was 100% blocked with gunge I mean the reaction products of the two different coolants created a sticky jelly like substance that did not allow water flow. When I drove the car in question the gauge climbed rapidly to the red zone and the only reason I got back home again was that it was nearly all down hill. Both the rad and the heater got back flushed pronto and worked OK after that. Your heater core probably wasn't on the important list for the mechanic who changed coolants without flushing. It's one of the things about modern coolants, mix different types at your peril.

**123rover50** · 13th January 2014, 09:08 AM

Finally got the case split. Had to grind a bit from the bottom of one side flap to let it past the fan housing.
Core looks good but then Dougal said he unsoldered his. This is alloy with plastic ends so I guess must be aftermarket. Washed out the goo but cant get a wire down the bottom pipe. Looks like a new aftermarket is on the shopping list.

Thread: Sherwood heater question

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