Plumbing between heater matrix and cooling system 1990 RRC 3.9

I have finally replaced the heater matrix which burst last September. All I need to do now is reconnect the (new) flow and return hoses between the matrix stubs and the pipes on the top of the engine.

Problem: I know, thanks to the parts book, which is inlet and outlet on the matrix. But I cannot remember which of the engine pipes connects to the matrix inlet and which is the return. Does it matter?

TIA

Richard

Reply to
Richard Savage
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not really

Reply to
Nige

On or around Thu, 26 Mar 2009 22:32:32 -0000, "Nige" enlightened us thusly:

The heater will work regardless of the flow direction, in fact.

However, study of the engine should determine which is the hot pipe and which the cool one. I could look at mine, if you like, although that won't tell you which goes to what heater connection, just like that - or do the heater connections happen in the engine-room?

Reply to
Austin Shackles

True, as it is force fed by the water pump, but it will be more efficient if the hot feed goes to the highest connection on the heater.

Reply to
Oily

Martin: I realise that the matrix is non-polarised but I would have thought that the inflow should be at the lowest point to ensure that it is purged of all air.

Austin: the stubs to the heater matrix protrude through the bulkhead and meet the flexible hoses between the back of the block and the bulkhead. Not the easiest place to get to when the matrix has burst and you are desperately trying to short circuit the matrix :-(

Richard

Reply to
Richard Savage

After initially bleeding the system there should be no air coming into the heater unless the head gasket is blowing, and water in the heater being cooled by the blower will sink to the bottom of the matrix as it will be more dense.

Double jointed fingers required for that job. :-)

Reply to
Oily

which I expect it to be doing so, despite the addition of a bottle of snake oil. I used this liquid glass stuff

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as recommended by my spannerer as an alternative to =A3800+ for a new headgasket - factoring in time, possible head skim and all manner of other fun things. So far so good.

Jokes apart Martin, what is the correct sequence to follow to ensure that all of the air is purged? I have seen people fill the system via the top rail filler until the rad is overflowing, cap the rad and then blow through the expansion bottle to purge the top rail. Does that make sense?

Oh yess!

Richard

Reply to
Richard Savage

which I expect it to be doing so, despite the addition of a bottle of snake oil. I used this liquid glass stuff

formatting link
recommended by my spannerer as an alternative to £800+ for a newheadgasket - factoring in time, possible head skim and all manner ofother fun things. So far so good. Jokes apart Martin, what is the correct sequence to follow to ensure that all of the air is purged? I have seen people fill the system via the top rail filler until the rad is overflowing, cap the rad and then blow through the expansion bottle to purge the top rail. Does that make sense?

I would say so, providing the header tank is full before it's blown through. As good a way as any. Defenders are ok as one heater pipe is higher than the other and also the highest part of the system, so you can remove the topmost heater hose with radiator cap etc. closed and fill through the heater pipe until water comes out of the heater itself.

Oh yess!

Richard

Reply to
Oily

On or around Fri, 27 Mar 2009 12:24:38 -0700 (PDT), Richard Savage enlightened us thusly:

heh.

I can look, if you want, how mine's plumbed.

Reply to
Austin Shackles

If you have nothing better to do Austin that would be very kind.

Richard

Reply to
Richard Savage

On or around Sat, 28 Mar 2009 04:11:03 -0700 (PDT), Richard Savage enlightened us thusly:

The pipe with the filler spout is connected to the bottom stub of the matrix in the engine bay.

Reply to
Austin Shackles

Perfect!

Thanks Austin.

Cheers

Richard

Reply to
Richard Savage

Thanks Martin

Cheers

Richard

Reply to
Richard Savage

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