Sealing wax and fuel lines, my Petter

It doesn't matter how filthy it is when you strip it down, it is when you assemble it that it must be both clean AND lubricated, don't put it together dry!

Peter

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Many thanks for that Peter, can I take it then a wax plug will at least help keep things out, or in, in the case of light oil. I was suprised to find the injector fuel line is steel, I was expecting copper, as the rusty line puzzled me at first.

Joules

Joules, At the point of injection there is a very high pressure which copper would not be able to withstand unless very thick. Steel is cheaper and stronger and just as easy to form.

Mart> Many thanks for that Peter, can I take it then a wax plug will at

It's a very high pressure and it's cyclic. Although copper will survive the static presure, it wold suffer from fatigue failure in a short time. In fact steel suffers fatigue failures in a reasonable time - it's a not uncommon failure in road diesels doing high mileages at relativeyl high rpm.

I wouldn't use candle wax to seal anything like this, but I might use vaseline and wipe it out later. Candle wax is full of all sorts of dreadful rubbish and certainly isn't easily soluble.

Thanks on that guys, I wasn't aware of the cyclic stress problem on fuel lines, but then this is my first diesel other than model aircraft, and they are just a tad more simple. Is there anything I can check for as I am cleaning the rust off the fuel line, and will now pay close attention to the pitting on it.

I understand on the wax, so Vaseline and bits of carrier bag taped over the ends will be the order of the day.

Cheers Joules

The actual hole in the pipe is very small indeed, it is not standard piping by any stretch of the imagination.

The nipples on each end are either hydraulically formed or are brazed on in the case of a repaired or fabricated pipe. Truck pipes use swaged on nipples these days.

Peter

-- Peter & Rita Forbes Email: snipped-for-privacy@easynet.co.uk Web:

As I understood things, I had been told, or had read, that in the case of diesel fuel it was not correct to use copper pipes anywhere from the tank to the pump. This, as I recall, was because of some chemical reaction between diesel fuel and copper forming a sludge. It was also recommended that you did not use a brass fuel tank.

Donald South Uist

Hello Joules. I just did some cylinder head work on my VW Rabbit diesel and I just sealed all the injectors, lines, etc. in Ziploc food storage bags. You can't get much cleaner than that and you have an airtight seal.

Interesting comment Donald, can you back that up with any further information. It's just all the canal boat engines I have seen are plumbed in copper, at least from the tank they are. Likewise diesel fired boilers and stoves.

Thanks Scott, I've got a box of sandwich bags I am using to cover and masking tape onto items in order to seal them for later.

Joules

I believe its zinc and therefore galvanising that should be avoided. ttfn Roland

ISTR that it wasn't the diesel fuel itself that reacted with zinc, but rather the sulphur in it. I assume that now we have ultra low sulphur diesel then it wouldn't be so much of a problem?

Regards

Philip T-E

Bringing this thread sort of to life... Donald your mention of brass/copper and fuel. That wouldn't have been in vegie diesel circles would it??? I just found reference to some stuff I am researching that states SVO (Straight Vegatable Oil) will react with copper, and that brass fittings are best avoided. Normal fossil diesel, no problems.

Joules