Expansion cap failure

[DangerousDerek]

I was pulled off the starting line 4 times this weekend having dropped water.
The temperature gauge was passed 90 and the fans were kicking in but surely the cap should hold the pressure right?

Can these caps fail? Where can I get a replacement or is there a better option.?

[WokingWedger]

I think they need to be the 'genuine' VW item. I had a pattern one fail on me.

Edited by WokingWedger on Monday 4th July 17:07

[mk1fan]

They release under pressure so if it hasn't failled then your system is over pressured.

[nigelj77]

I had one of these fail, think it was venting too early, I noticed the hoses were being sucked down so I guess it was releasing pressure too soon causing coolant loss the almost creating a vacuum when it cooled down, genuine ones aren't cheap but put mine right straight away.

[nawarne]

What's been said...DO NOT get pattern part.

I got one from company specializing in German, Swedish and French cars (clue in the name) and although made in Germany was rubbish quality. Failed in Le Mans,,,luckily VAG dealership fairly close (Seat, actually) had one - Eu14, and I was on my way. The pattern part lasted about 500 miles!!

Exactly the same failure mode - dumped coolant when hot - guess the relief valve part of the cap was not man enough.

Nivk

[737 FLF]

Got a REAL one for approx £6.00 from GSF.

Edited by 737 FLF on Monday 4th July 18:16

[DangerousDerek]

737 FLF said:

Got a REAL one for approx £6.00 from GSF.

Edited by 737 FLF on Monday 4th July 18:16

Anyone know the correct VW the cap comes from?
Or better still a part number?

[WokingWedger]

I believe it's a mk 1 Golf but somebody will be along soon to confirm

[nawarne]

Sardonicus said:

WokingWedger said:

I believe it's a mk 1 Golf but somebody will be along soon to confirm

Genuine only IMO from mid 70's late 80's Audi 50/80 Polo Golf Passat Jetta & lots of superseded numbers 443121321 or 171121321 or 171121321B 171121321C or 171121321D or 171121321F or 321121321D

Edited by Sardonicus on Monday 4th July 22:48

Re: my previous post in sourcing a replacement in Le Mans.

On the Monday morning after the race I went up to the industrial units to the West of Le Mans...When I went into the VW (car) dealership (because there is also a commercial dealership close by), I asked for a 'Golf' "bouchon" and the spares guy said "Golf deux" - so a Golf Mk.2.

Does look like the same cap was used on several VAG group cars.

Nick

[ClassiChimi]

Sardonicus said:

Forget those last part numbers just checked with my local TPS and the latest number is 443 121 321 not sure if the guy was just being unhelpful or not but those last batch of numbers just kept coming up obsolete(not superseding to latest) I ordered one anyway for stock 14 squids

Will that be nice and dark blue Simon,,, if so order another one for the shelf and I'll have that one off you
Only joking,
Why do I feel the need for one of those caps in my life all of a sudden,, Pistonheads,,, it's a nightmare

I've already banned myself from Facebook,, it must have cost me £1600 in about 3 months

Edited by ClassiChimi on Tuesday 5th July 10:42

[ChimpOnGas]

German Auto Spares who have a store on E-Bay offer a quality German made Febi Bilstein brand cap (genuine V.A.G part manufacturer) for £4.77 delivered to your door.

http://www.ebay.co.uk/itm/Expansion-tank-cap-44312...

Febi Bilstein only make quality parts and mostly for OEM manufacturers.

http://www.febi.com/febicouk/home.html

Seems like a good deal?

[N7GTX]

That part number - 443 121 321 - is shown on the TVRCC page as being correct for the original.

http://www.chimaerapages.com/parts-list.html

[ClassiChimi]

As this is using the correct part number I've given it a go £4.77 is almost the price of a coffee now days so what can I loose.

[DangerousDerek]

ClassiChimi said:

As this is using the correct part number I've given it a go £4.77 is almost the price of a coffee now days so what can I loose.

Ive also ordered one at that price but will also be going to a dealership to get a genuine part.

[ClassiChimi]

I could loose lots of water,, hmmm!

A spare seems a good idea so I'll see what it looks like when it arrives.

I have a few splash marks around the expansion bottle so I need to clean it off, work out if it's water been thrown up there or its venting out although I haven't really used any water.
The beauty of a clean engine bay gives clear indication of something wrong, st up it ain't

[ChimpOnGas]

There's no way on God's earth a huge & well respected company like Febi Bilstein who work to the rules of mass production and rely on their quality reputation would run a "VAG production line" and an "iffy on the side not so good quality" production line for the very same cap.

When a company like Febi Bilstein go to the expense of tooling up for such things you can be sure it's going to be the very same cap every time, the upfront cost is all in the tooling... and that's a mass production fact.

What you pay for with the genuine cap is the guy that takes it from the Febi Bilstein production line and puts it in a VAG bag with a VAG part number on it, the VAG stock holding and distribution costs, and finally the VAG main dealer's margin and distribution costs.

Rest assured... It's the very same cap, and off the same production line, made by the same manufacturer, on the same tooling and made to exactly the same standards... there's just a lot less mouths to feed with the one in my link.

[ClassiChimi]

In fairness to the sellor they also point out its a genuine part.
But it's so cheap you do wonder,,, or is it the mark up on these items is just simply criminal.
Either way fo less than a Fiver delivered to your door,, if it even arrives I'll be surprised at that price ,

[nawarne]

ChimpOnGas said:

There's no way on God's earth a huge & well respected company like Febi Bilstein who work to the rules of mass production and rely on their quality reputation would run a "VAG production line" and an "iffy on the side not so good quality" production line for the very same cap.

When a company like Febi Bilstein go to the expense of tooling up for such things you can be sure it's going to be the very same cap every time, the upfront cost is all in the tooling... and that's a mass production fact.

What you pay for with the genuine cap is the guy that takes it from the Febi Bilstein production line and puts it in a VAG bag with a VAG part number on it, the VAG stock holding and distribution costs, and finally the VAG main dealer's margin and distribution costs.

Rest assured... It's the very same cap, and off the same production line, made by the same manufacturer, on the same tooling and made to exactly the same standards... there's just a lot less mouths to feed with the one in my link.

Dave, hear what you're saying, but I would highlight that there have been problems with the current batch of plug extenders supplied by TVR Car Parts.

They are branded 'BERU' - also a well respected German component manufacturer, but a mate's experience with them clearly demonstrates that they were not made to original spec's.

We spoke to Tim Lamont at the N.Garner open day last September, and his opinion was that they were probably outsourced to China - - Result? my mate had two sets that broke down within a couple of months and caused an annoying miss-fire....I wouldn't always assume that batch runs of parts for 'older' cars are necessarily made on the original production line?

Nick

[Sardonicus]

Dave I was trying to help Derek not you rather than see him make a wrong choice on cap quality and have a possibility of failure ...again dont know why I bother so in future wont EDITED previous comments so not to mislead people paying for a genuine cap make bankrupt them clearly

Edited by Sardonicus on Wednesday 6th July 09:40

[ChimpOnGas]

Just saying the same thing is available for less than a fiver, thought that was helpful too?

Peace and love to you all

As for those dreadful extenders, I say chuck em in the bin