Coolant and Heating System overhaul 1

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Replacing metal pipes with plastic


Ermie571: (Emma) Problem……leaking radiator, temp repair on metal cooling pipe that needed doing properly

Vehicle = A reg converted panel van. Originally 1.9, now 2.1 Cooling system….mixture of early 1.9 and late 2.1 Mechanical competence = happy to give it a go, but no expert!!! This is a beginners guide, and has tips for those, who like me, don’t know the ins and outs of their bus, but are picking things up along the way.

Tools needed

  • Screw driver set – flat and cross heads
  • Hammer
  • Socket set
  • Stanley knife
  • Circlip pliers
  • Adjustable spanner (needed for removing the thermoswitch from rad – was too deep for the socket set, and didn’t have a ring big enough!)
  • Hacksaw for cutting metal pipes to remove if desired, and to use as joining pieces if needed

Parts needed

  • Jubilee clips – we put all new on
  • Fuel line and clips
  • New filler cap metal ring (mine had rusted through – had spare in garage)
  • May need to replace other parts of fuel system – neck, breather hoses etc depending on how well they come off
  • Plastic pipes
  • Rubber hose

The work

Before you start it may be worth carefully noting which pipe joins to where…. Mark them, or write it down etc….ie where each front to back joins to at the radiator end and at the engine end! Silly, obvious and damn frustrating when you didn’t do it!! Also good to mark the front and back of the replacement pipes – again, obvious, and we did get it right from memory…but we did check the orientation with our other van as we were not 100% sure.

Also, the plastic pipes are slightly bigger than the metal ones. Ours, second hand, came with some hoses. We had to make joins where pipes didn’t fit – used bits of the old metal pipe to provide a solid union on which to clamp the rubber hoses.

What we did. NB – There was little water in the system…and what was in there we drained down the previous day by releasing as many hoses as we could!!

a)drop radiator: followed advice on forum – came out easily, but the following may help those who haven’t done it before! Start by removing the spare tyre – put it to one side; it could be a little while before it goes back! Now you need to remove the metal dish that supports the spare wheel….start by removing the U shaped clips on the metal arms that run underneath the rad to support the dish. Once these were out, we had to hit the metal arms at the hinge with the hammer – they were well rusted in there. Once they were out that end, a quick twist removed them from the front of the van. Arms and dish stacked up with the spare tyre. Remove all the grills. Undo electrics on the radiator. Remove and store the heat sensor screwed in the front of the rad. You will need an assistant for the next bit…..we had 2 of us to hold the rad, while John was underneath undoing the bolts. 4 bolts – 2 on each bracket. Came out easily enough, and the rad lowered straight down. Job done. NOTE – at each corner of the radiator there is a little lug, which has a rubber washer on it. These stop the rad rattling / moving on its mountings. Make sure you keep these in a safe place!

b)Lower the petrol tank – try do this with as little petrol in it as possible!!! We had less than a ¼ tank – still managed to lose some! Again – an assistant is advisable! Need to disconnect the fuel filling system….3 screws at the filler neck – and once mine came to bits it revealed…the rubber filler neck had cracked and split, the metal ring behind it had rusted through, the filler tube itself was fine. Breather hoses and tanks were fine too! The tube just pushes into the tank – turn it, wiggle and pull to remove it. Have a selection of “bungs” handy to shove in fuel lines to stop the loss of petrol – pencils, chopsticks, bolts etc all useful. Gets a bit vague here….as I had to leave to go get replacement fuel line as some of mine was showing wear…. But the lads undid the bolts that hold the straps up, then lowered tank. We did have the trolley jack underneath it to give a little extra support as well. It just hooks on the chassis at the near the front of the van.

c)With the spare out, and the tank dropped, it was time to remove the metal pipes. Pulling, pushing, twisting and shoving all came in useful here. Looking back, it would probably have made the easier if we had cut the pipes…..but had no decent hack saw. They did come out eventually.

d)Stopped for cup of tea and a break.

e)Built up courage to insert first plastic pipe. Had three people doing this….bit of overkill? Pipe doesn’t slide in easily….have to twist it etc to get the kinks through the chassis. This first one went in from the radiator end….not sure if it would have been easier from the other end!

f)There was no way the second pipe was going in from the radiator end!! So, pushed it in from the rear. Got there eventually. Did not have to adjust the hole in the chassis.

g)Replaced the radiator (exact reverse of fitting), connected all the hoses, making joins where necessary. Refit petrol tank, replacing fuel line as necessary. Refit the fuel filler neck in the body, then refit the the filler tube. Needs a bit of wiggling and pushing to get it all lined up.

h)Fill with water and test for leaks

i)Drain, fill with correct water anti-freeze mix, bleed and drive!!

A 2nd review of the job


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 (go to 'silicone range' / 'straight silicone reducers' / 32-38mm I.D. straight silicone reducer (SR-32/3Cool @£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 !!! Glenn

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Checking your plastic pipes

Other coolant pipe tips