Fuel Tank Breather Hose Clamp

[hiltow]

Bit of a long shot, but if anyone has had experience of replacing the fuel tank on a Scirocco Mk2, can you recall what hype of hose clamp secures the larger width, clear reinforced breather hose to the fuel tank connection?

(This is the hose that lives behind the platic guard in the offside rear wheelarch and runs between the tank and the top of the fuel filler neck and gravity valve)

Is the original clamp an Oetiker ear-type crimp clamp or a Jubilee-type clamp? Better still, if it's Oetiker, can anyone post a picture of the type or know what the size marking was stamped into the banding?

(the clamp is item 11 in the drawing below)

[GT_II]

If it's the same as at the filler neck end (which the diagram suggests), the clamp originally fitted appears to be an Oetiker type 153 1-ear clamp. The one my car's filler neck is too rusty to make out any size marking. The superseding part is a 16-28 x 9 x 0.5 mm worm drive clip N 90561801, likely around £2 or £3 from VW dealers.

[Village Idiots]

Buy specific fuel line clamps off e-bay appropriate to the diameter of the breather hose. Proper job and cheaper.

[hiltow]

Thanks GT_II - that's useful, as I want to keep the car to the original specification; even down to this level of detail.

I want to find out what the right clamp is in advance of doing the job so that the work isn't held-up waiting for the right size of Oetiker clip to arrive.

As you say, the 16-28mm clamping range is for the worm-drive clamp that you would get from VW now, but that range doesn't correspond to anything in the Oetiker catalogue for the Type 153 and 154 one-ear clamps.

Cross-referencing the other Oetiker one-ear clamps on the car that I can see with their clamping range in the Oetiker catalogue, it looks like the clamping ranges for these clips are at the higher end of the range compared with the worm-drive equivalents (e.g. OET 13.3 RER Clamps on the car has a 10.6-12.6mm range where the worm-drive type equivalent now listed by VW has a 8-12mm range quoted for the pipe it's supposed to secure).

On those lines, I reckon an 17.5 Type 153 (15.3 – 17.5mm) or 18.5 Type 154 (15.6-17.8mm) are probably the right ones to use for the 16mm diameter hose that is part no. 10 in the diagram.

[GT_II]

VW's parts microfiche from 1992 also lists the clamp as a worm drive clip, then part number N 90071801, sized 16-27 mm, which is different from the crimped Oetiker clip used at that time in the factory.

The hose is listed on the fiche as 15.5 x 2.5 x 850. Does the 15.5 relate to the inside or outside diameter of the hose? If inside, then you would need a clip to suit an overall diameter of around 20 - 21 mm.

I admire your attention to detail and efforts to preserve originality. There were a few non-genuine bits and pieces on mine when I bought it - rear exhaust box, filters, alternator belt and battery spring to mind, and one by one they had to go. It's an interesting question though how far to go to maintain originality when the official replacement parts often differ from those fitted in the factory, and potentially supersede several times before being discontinued.

[hiltow]

I think I'm going to have to bite the bullet and order some smal quantities of a range of different size Oetiker clamps (single ear and with-without insert), which is what I wanted to avoid having to do, but sometimes it's the only way! By hedging my bets, at least I should have the right one available to keep the job moving.

Cheers GT_II for the info. I guess VW specified a worm-drive clamp for the aftermarket as in some ways it's easier to fit than ear clamps in a DIY situation as no special crimping tool's needed.

Yes, I like things to be replaced if they have to with a part that's 100% original and genuine. The only 'modification' to my car as such is using the later rubber-type rocker cover gasket instead of the cork one, but then I don't mind that when the original specification part never did its job properly.

In tracking down some of the original standard fixings that VW used on our cars, it's clear that the components they used are from quality, recognised manufacturers. Even the orange-coloured plastic cable ties used in the engine bay are made by T&B who manufacture these for use in jet airliners, and are of a higgher strength than usual - they're a 'world leader' in cable ties!

[GT_II]

VW didn't always use the best quality fixings in the factory - only in critical areas. The fuel hose clips are stainless steel, but the 1-ear clips fitted to the tank vent hose are certainly not! I am pretty sure the replacement worm drive clips are stainless steel.

I suspect one reason for differences between parts fitted in the factory and genuine replacement parts is to reduce the number of parts that need to be warehoused and distributed. Another would be speed of assembly - all important on the production line. For example a 1-ear clip probably takes 1 second to tighten, a worm drive clip probably 10. And another might be cost, A box of 5000 galvanised Oetiker clips would likely be considerably cheaper than the equivalent number of worm drive clips.