Heater tubes in the chassis spine

[EuropaTC]

Hi folks,

After several weeks of behaving itself, this morning I found a pool of water under the car and it turned out to be coolant. I found one of the steel tubes which is conveniently welded into the chassis has corroded and the rubber hose was leaking at the joint.

For the moment there's enough tubing left to re-make the joint but from what I can see I have an interesting job in my future. So.....   has anyone ever replaced these tubes without lifting the body off ?  It doesn't look to me as if you can replace with a single long tube with the engine in place and the body on the chassis.

If not, I'm open to suggestions for bodges/quick fixes/whatever to get through the summer because I don't really want to start ripping the car apart while there's sunshine outside.

cheers

Brian

[4129R]

The long steel tube below the expansion tank/battery goes into a rubber hose, which goes into the long tube to the rad from the pump.

You can bypass the whole steel tube by a much longer rubber hose. 

If you are talking about the tubes directly below the heater, you are welcome to come and see a chassis off the shell, which is all built up ready to fit, so you can work out whether it is possible to repair the tube in the box section.

Alex, (just down the road).

[TurboFource]

I replaced mine with aluminum ones I fabricated and it was not easy getting the
original steel ones out of the chassis with the body off the chassis...the welds
are not that easy to get to.

[EuropaTC]

The long steel tube below the expansion tank/battery goes into a rubber hose, which goes into the long tube to the rad from the pump.

Hi Alex,
That's the one that's corroded in the last inch or two. Right now I've just fitted a longer rubber hose which is hard up against the chassis closing plate to hopefully get me through the summer. 

I can see it being do-able with the body lifted up in the air, I just wondered if there was anyone who'd done the job in situ or if there are any better ideas.

I must admit, apart from "feeling very depressed" as Marvin would say (HHGTTG for those old enough to remember) I'm currently thinking of bodging it through summer then lifting the body to replace all the transfer/heater tubing in the chassis. It's all 50yrs old, there's got to be some potential for upsetting me again in the future.

DIY fabrication in stainless sounds a plan, with a re-design to get away from those awkward 1/2" hoses between the engine & chassis spine tubes. Maybe bring them into the engine bay with re-designed transfer tubes ?

Brian

[Grumblebuns]

Brian. I'm not to clear on which is leaking. The only coolant tube that I can recall that is welded to the chassis is the one going from the header tank to the coolant from the housing to radiator. See screen shot, item #15, water feed pipe. Are the heater tube nipples sticking out of the chassis also welded?

[Sandyman]

Hi, yes there are heater tubes running from the engine bay to just behind the center console. These are welded in place. They run along the top of the chassis box. The ones in my old chassis were rusted and leaking.
Sandy

[jbcollier]

I’ve done it insitu with the drive line in place.  Not fun but doable.  I had to do mine in two pieces because I have a cable shifter, ac pipes and oil cooler pipes all inside the chassis.  You might be able to do it in one piece as you’ll have more wiggle room.

Wiggle the old pipes back and forth and the welds will break.  Smooth out the holes so you can fit hose as a grommet to protect the new pipes in the holes.

Always, always fit new pipes if you have the chassis out.  I didn’t.  I just pressure tested them but they leaked with hot coolant.

[EuropaTC]

Joji,

This photo is very blurred but it's a scan from an old 35mm taken when I repaired the chassis. I've marked the tubes in question, roughly 3/8" steel and from memory they are tack welded at the entrance & exit from the chassis spine. The one that's failed is the one from the heater valve although as I said there's enough left to just about get a longer rubber hose on it.

John, thanks for your input, that's very encouraging. I can see how to get the old ones out and I'm skinny enough that I'll be able to smooth out the holes but I'd never have thought it possible to thread a new one in. I'll need to take another look at the task - did you make the holes much larger to help ? If I can do it without removing the body then I'll give it a go and do the proper job when the summer ends.

You're right though, anyone doing a chassis change these days should be replacing these things as a matter of course. I didn't, but at that point the chassis was only about 10yrs old and I thought they were ok. I suppose they were, they've been there for another 30yrs but now, how I wished I'd fitted some stainless tubing !

Brian

[4129R]

A copper replacement tube would be easy to bend to shape, and would not corrode.

I use copper for the vacuum pipe from inlet manifold to servo.

[bert knip]

I have replaced them with copper bendable tubing.
Makes it easyer to sneak them in.
But my body was off.

[EuropaTC]

Hmm, copper tubing sounds a possible option especially if I can get away with microbore (10mm OD). 

One of the things I really like about this forum is how many ideas we have on repairs/fixes outside the box.

Brian

[4129R]

The OD of that tube is 12.5-13.0 mm.

Copper tubing appears to come in 10, 12, and 15mm OD.

https://www.ebay.co.uk/itm/192858456314

There are 2 x 90' bends on that tube. It is welded to the chassis in 2 places on those bends. 

It is a total of 800mm long.

[GavinT]

I'm on the wiggles bandwagon, too.

I've never done this but I'm thinking to wiggle the rearmost tube section till it breaks off and then use either a stepped drill (if there's room) or Dremel to separate any remnant of the tube at the rear box section bulkhead. Then the remaining forward part should be wiggleable till it breaks near the heater.

I suspect this is a bit like frozen door hinges. One could spend days of hope and glory expecting success with penetrating fluid only to realise the job called for five minutes with a reciprocating saw.

[jbcollier]

Make up the replacement tube and feed it through the gearshift hole.  Or, in through the large hole by the gear lever and out the gearshift hole until you get it all in then back.  Maybe, fingers crossed, you might be able to get it in.  If not, cut it in two and then it is easy.

[EuropaTC]

One thing about this forum is that when I found the problem I was really fed up and pessimistic about the whole deal. Now, just a few days later with all these ideas coming in I'm feeling a lot more positive. So thanks to all.

After John said it was possible without pulling the engine I had another look. I doubt I can get a step drill in but a dremel looks do-able. The cabin end should be ok. Copper tube is current favourite, I can use olives soldered in place to imitate the flared ends and secure the hoses.

I like the idea of going in the hole underneath the elbow pad on the centre console, I reckon that could work very well. Until now I've been wondering how to get it all past the engine from the back, with that method I wouldn't have to.

More thinking to do, another "coat of looking at it". Thanks again everyone.

Brian