Replacing metal water pipes

Big lumps of metals and spanners.

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glenn77
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Replacing metal water pipes

Post by glenn77 »

For those of you who were asking here is what i did. Feel free to copy or move this post to a more appropriate section.

Problem : metal water pipes corroded on 1984 1.9 auto camper.
Solution : Replace metal pipes with plastic vw ones.

Yes they are hard to come by but not impossible - ask/look around ebay - i got mine within hours from ebay for £28 + £10 p+p. They came with good metal inserts in each of the 4 ends. Also after reading i found out they must have been off a diesel as one of the pipes was shorter by a foot.

Ok - to the van - jack up rear o/s , front both sides and SUPPORT WITH AXLE STANDS !!! - not just jacks etc.
Underneath remove tinware on o/s under cylinder head - this allows access to rubber hoses.
In engine bay MARK ON HOSES the feed and return (i just looked at the 2 pipes and marked them left and right and kept this notation from engine to radiator).
Undo the hose clips that attach the metal pipes to the rubber hoses in the engine bay. Prise the rubber hoses off the metal pipes.
Underneath at the front of the van in front of the petrol tank undo the hose clips and prise the hoses off the metal pipes.
Beware water will gush out !!! watch your eyes.
Now i did remove the petrol tank and found the job a lot easier to do, the plastic pipes although flexible arent that flexible and they do have to go through some little gaps.
To remove the tank - drain (i pulled off the fuel pipe at the rear of the tank and drained the petrol into a plastic can). Next under the front o/s wheel arch remove large hose clip on fuel filler neck and prise filler pipe out. Remove all the smaller pipes from the expansion tanks (there are 4 pipes) and label for replacement. Under the van at the front of the tank are 2 x 13mm nuts on the tank straps. Support the tank -(i used a small trolley jack with a bit of ply on to rest the tank on). Undo the nuts and slowly lower the tank down - as it lowers reach on top and remove the wiring for the sender unit. Remove the 2 metal tank straps and move the tank out of the way.The filler pipe just pushes into the tank . Dont worry about all the pipes and grommits that ping out of the top of the tank as you lower it - you can fairly easily replace them when the tank is nearly back up in position through the wheel arches.
Now back to removing the metal pipes. I found it easier to cut the pipes into sections to remove them rather than trying to get them out whole. The pipes go through a hole in the chassis underneath near the back of the fuel tank, i cut here and towards the rear where they start to bend up towards the engine. A junior hacksaw did the job fairly easily - anything bigger and its banged knuckles time. Remove the sections of metal pipe and keep for later.
OK - now to put the plastic ones into place. Before you start lay the 2 plastic pipes out side by side - you should notice that at the front end on of the pipes is dead straight and the other has a slight kink about 6 inches from the end. The straight pipe goes to the near side whilst the other bent pipe goes to the off side (i got them wrong the first time and had to take them out again).
I found it easiest to put the pipes through as a pair matching the contours and bends together to feed them through as one. I also found it easier to feed them through from the front of the van. The hardest part is forcing them through the hole in the chassis but they do fit believe me.
With the pipes roughly in position we now have to fabricate some way of joining the plastic to the rubber.
You will need 4 hose reducers. I shopped around and found this place to be the cheapest http://www.hoseworld.com/ (go to 'silicone range' / 'straight silicone reducers' / 32-38mm I.D. straight silicone reducer (SR-32/38) @£3.78 +vat each, worked out at about £25 for the lot and they delivered fast). You will also need some good quality hose clips ( 4x 38mm , 8x 32mm).
Back to the metal pipes you cut off - you will need to cut 4 lengths of pipe about 6 inches long, choose the best unrusted bits of pipe. Put a silicone reducer onto each pipe about 2" and fix with hose clip (32mm).
Under the van push the rest of the metal pipe into the existing rubber tube remembering to put another 32mm hose clip over each pipe first!
Then slip a 38mm hose clip over the reducer and push it over the end of the plastic pipe. Work the hose clips round into positions that you can easily get a spanner on to tighten them and ... tighten them up.
Do this for each of the 4 ends of the pipes remembering which is the feed and return (left and right from earlier).
The pipes should now all be firmly attached. Use cable ties to tie up the pipes to support their weight over the length.
Replace the fuel tank - put the tank straps back rest the tank on them - remember to refit the sender wiring, jack the tank back up wiggling about to position. Reach through from the wheel arches and replace the piping. Refit the filler pipe in the filler neck.
Bolt up the straps once in position. Refit the fuel lines (fit a new fuel filter whist youre there).
Refit the tinware under the rear. Make sure no rubber pipes are touching the exhaust as happened on mine !!!
Remove the rear jack leaving the front still up.
Remove the water filler cap in the engine bay. Remove the front grille and loosen the radiator blled net on the top LHS of the rad. Fill with plain water and bleed through as described in the wiki.
Go for a local run about to check for leaks.
If all is well drain the water out and top up with 9 litres of antifreeze (cost me £12 for 10 litres) and water - bleed and refill as necessary.
And thats it !!!

Hope this helps. :D

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lhd
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Post by lhd »

Glenn stick it in the Wiki. :wink:

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HarryMann
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Post by HarryMann »

Have done that, so we now have two fairly comprehensive articles on replacing metal with plastic coolant pipes in the Wiki.. thanks Glenn, a good variation there.

What we'd like now is some alternative (non VW) solutions if anyone has used flexible all the way, or another form of plastic or metal pipe... quite common in the States for some reason, maybe the sapres are harder to find, or they like rebuilding with s/s gumma gumma marine pipes for a theoretical 100 year maintenance free cooling system :wink:
Last edited by HarryMann on 16 Oct 2008, 11:15, edited 1 time in total.

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Ian Hulley
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Post by Ian Hulley »

I'm investigating some flexy plastic hose that has an integral stainless spiral re-inforcement yet is still flexible enough to fasten in place. Will report back when costed etc.

Ian.
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