Heater tubes in the chassis spine

[bert knip]

I used 15mm from homedepot, comes close to the original.
However it easily bends, for the 90 degrees bends you will need a pipe bender.

[GavinT]

I reckon the plumbing type olives might be a bit too thick but I've soldered a piece if copper wire around a tube to serve the same function.

The OEM tubes are 1/2" OD and rather thin walled - perhaps somewhere around 1 mm.
There's also brass unions and 90° right angle fittings that might be useful.

[EuropaTC]

Update......

Thanks to some great ideas posted here, both heater tubes are now replaced and working.  Detailed method is in the PDF but the executive summary is;

• Drain coolant from the heater circuit (no need to drain everything)
• Remove centre console, disconnect heater hoses from heater matrix
• Access via handbrake adjustment hole, bend,cut & remove tubes in 2 pieces
• Make up new tubes in 12mm Copper, I used fittings but you can make a swept bend if preferred
• Insert tubes from inside the cabin
• I made plastic split collars to prevent the copper being worn away by the chassis steel. If you want to use rubber grommets then the holes need enlarging

And that's about it. Thanks to all who contributed ideas, if not for this forum topic I reckon I'd have just pulled the engine to get them out because I never imagined it would be possible with the engine/transmission in place.

Thanks again folks....

Brian

[Steve_Lindford]

Could you have used flexible pipe for the whole job??

Steve

[EuropaTC]

Could you have used flexible pipe for the whole job??
Steve

Yes, it would have been possible to use conventional 1/2" rubber heater hose for the complete run and I did consider that, but in the end I decided that would have brought in other issues. 

There's plenty of space in the central spine for 2 rubber hoses but the first problem would have been getting access through the end plate near the engine bay. They might squeeze through the gear linkage hole but it would be tight and not something I'd fancy long term.  It's so crowded there that I couldn't imagine drilling new holes so the obvious place is where the old steel tubes are and they have to come out to make that possible.

Then you have to get the hoses out of the spine and into the cabin. Again, the obvious place is where the steel tubes exit but as mentioned, the holes in the chassis there are probably no more than 5/8" so they'd need opening up.

To be honest, the hardest part of the job was cleaning up those holes where the steel tubes had been tacked in place. If you could get a step drill in there it would be a different tale, as it would be if the body was off, but trying to do it with everything there led me to make compromises. I even considered 8/10mm tube with adaptors at either end as it's definitely more flexible but in the end I stuck with 12mm just in case the heater couldn't demist with a lower flow rate.

Brian

[GavinT]

Well done, Brian - always good to see a plan come together.

I suppose it's too late to bring this up, but . . . 
Reckon it'd be doable to either weld a nut on the reamer or just file some flats so as to use a long socket extension inside the tunnel.

https://www.jegs.com/i/JEGS/555/W2967/10002/-1#

[EuropaTC]

Oh that's neat. I've never seen anything like that (but I'm not a real practical engineer, I've just got a bit of paper that says I am   )

You're right, I could see something like that working very well because the steel is only, what, 1.5mm thick ?  I think I need those toys in my toybox.....

Brian

[Steve_Lindford]

Could you have used flexible pipe for the whole job??
Steve

Yes, it would have been possible to use conventional 1/2" rubber heater hose for the complete run and I did consider that

Sounds like you spent a lot of time thinking - that happens a lot...

[Fotog]

That's a nice write-up, Brian.  Thank you.
Vince

[Footer]

I agree with Vince, it’s a very nice write up and pictures as well.
Particularly pertinent for me since I’m pulling the engine to replace all four tubes.

Thanks

Bob