60x Injector Hard Lines, Dissected
 

Being another adventure in engineering.

One of my injector hard lines broke right at the injection pump. A member here was kind enough to send me a used spare, but while I waited for the mail, I decided to experiment a bit.

The first thing I tried was the compression fitting ferrule trick. For those who've never heard of this, the ferrule from a common 3/8" brass compression fitting will neatly fit an injector pipe. You can use the ferrule alone at the tip of an injector line, and simply tighten the original nut down onto it to crimp it in place. This works surprisingly well, to the point where I would have considered it a permanent fix, except I'm not sure if corrosion would become a problem. The first picture shows the brass fitting snugged to the line, compared to a stock end. I will now keep a couple of compression fittings in my bag of tricks for future emergencies.

I was passing the MB dealer and decided to see if they had a line. Surprisingly, they did. And even more surprising, it was bent to shape (the last time I tried this, the line was straight and it was murder to to get the bends right.) So I took it home and fitted it up. I know it's not welcome to bash an OE MB part, but this made-in-Germany part is total cr_p. :mad: No matter how I tried, I couldn't get the injector end to seal tightly. As the engine cranked, fuel sprayed out all around the fitting. I'll have to try to bring the line back to MB, but guaranteed they will blame the messenger.

The next illustration shows the problem. The new line is shown alongside two original lines. The original end seems to be a separate forging, swaged onto the end of the line. Behind the end, there is a thick spacer which mates against the inside of the nut. The sides of the forging have a two angle grind, which mates with the gland in the injector. The new piece is also a swaged end. But notice that there is no spacer washer. The side that mates to the nut is angled rather than flat, which doesn't help. And the mating surfaces are crudely finished. No matter how much pressure I applied to the nut, this fitting would not seal to the injector.

Myonly hope is that this line was meant to be used on a more modern Sprinter van, which has engines based on the 602. But something in the design changed through the years, and the part does not work on an original 60x.

The used line arrived yesterday, and I installed it today. It went in with no trouble, sealed, and the job is done. So the moral is, OE is best, as long as it's old OE.

In pic number 2 you see that if there is no washer on the bottom one that is what is keeping it from sealing.

The older models like mine have the hard line ends silver brazed on. The ends on the newer lines look like they were swedged/cold formed and the metal on them needs to be soft in order to squeeze them into shape.

We had a hand powered hard line swedging setup at one place where I worked. It is also possible for the person not to allow enough tubing sticking out so the swedged end becomes malformed.

How do you get the compression fitting to swage onto the line? Just swage it down onto the IP valve(?) fitting?

The tip of the injection pipe had broken off cleanly, leaving smooth pipe. I slipped the ferrule onto the pipe, and simply closed up the assembly with the regular IP valve nut. When the soft brass ferrule is compressed into the gland in the top of the valve, the ferrule becomes swaged to the end of the pipe and conformed to the gland. The seal is perfect.