Plastic Welding Repair for Expansion Tank

[ukkid35]

Is it possible to repair an expansion tank, or have it repaired professionally

Sadly it can't be replaced with a new tank for £20, even used ones are about £100 and don't last that long, so a repair option would be great

[DVandrews]

Provided it’s the right type of plastic then you should be able to make a join repair, the trick will be to make it pressure proof, I’ve repaired a large number of hard to source plastic parts by plastic welding, but only one had to give an airtight sea, it was quite trick and I had to add some similar plastic from another sourcel, The rest were mostly repairs to cambelt covers and other structures where it didn't matter if the join was permeable.

Dave

[GreenV8S]

I've never done a plastic weld that needed to be pressure proof but I imagine you'll need to eliminate all dirt from the weld to have any chance - that probably means cleaning both surfaces and removing the exposed faces of the crack. Keying the surface and putting an epoxy patch on the inside over the weld would improve your chances imo.

[VanDiesel99]

I get that the Plastic Tank for your particular vehicle isn't available at realistic cost, but maybe its possible to fit a non-standard expansion tank?

I've recently fitted a Plastic Header Tank to my car which never had one fitted as standard. It was quite a task in all, but I've various tips if you want to go that route.

[ukkid35]

Yes, there is an American tank available in aluminium for $350 plus shipping and taxes

It does have the level sensor fitment allowing you to transfer the sensor from your old tank

While the level sensor seems like a luxury, the only time it wasn't working I had a pinhole leak in one of the heater hoses and ran low on coolant as a result

Edited by ukkid35 on Thursday 7th May 00:13

[GreenV8S]

ukkid35 said:

Yes, there is an American tank available in aluminium for $350 plus shipping and taxes

Would you consider fitting a generic tank or one from another vehicle to avoid the extortionate prices you're being quoted for the standard ones?

[E-bmw]

VanDiesel99 said:

I get that the Plastic Tank for your particular vehicle isn't available at realistic cost, but maybe its possible to fit a non-standard expansion tank?

I've recently fitted a Plastic Header Tank to my car which never had one fitted as standard. It was quite a task in all, but I've various tips if you want to go that route.

^^^^ Wot 'e said.

That is what I would be doing, plastic repairs are notoriously unreliable when under pressure & heat cycles.