Thread: Sherwood heater question

G`day ,

Soft Dash has a tap in the engine bay .

The others move flaps the coolant flow not controled .

Ah, thanks. So there must be a blockage somewhere so its got to come out anyway.

The two heater core connections poke through the firewall for access from the engine-bay.
All flushing can be done from that side.

I undid the hoses where they join the steel pipes on top of the engine.
Put a garden hose in one and nothing comes out the other.
Tried air with the compressor too. Still no flow at all. That let me think that there was a shut valve there.
Taking the bulkhead ends off now. Top is OK but the bottom buts up against something on the block and wont slide off. I will have to move the heater back a bit to get room to get the elbow off anyway. Be interesting to see why its blocked.
Keith

Originally Posted by 123rover50

I undid the hoses where they join the steel pipes on top of the engine.
Put a garden hose in one and nothing comes out the other.

You don't know how lucky you are. Often the water goes into the heater core and out via the foot-wells.

I have been into the heater box on my 85 several times (once for that water out the footwells thing) and wrecked an 88 years ago. They had no intentional flow disruptions to the heater cores.

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

That said.

My heater worked heaps better after getting an end unsoldered and the cores rodded out.

Originally Posted by Dougal

That said.

My heater worked heaps better after getting an end unsoldered and the cores rodded out.

an even better option if you dont mind making the effort to get it out.