280sl oil pressure gauge line fabrication

[ctaylor738]

As I was attaching the oil pressure line to the engine fitting on a 280sl, the line snapped at the engine end.  Replacement lines are NLA, so I will need to make a new line using the existing fittings.  The line material is polyamide M6xM3.2 and is readily available.  It is heated and pushed on the the barb fittings. 

I have not had much success working with this material.  If you get it too hot, it will buckle as you push it on to the fitting.  Not hot enough, and it not go all the way on to the fitting.  Belmetric has a video showing a tool that would be a great help, but they no longer sell it and could not identify a source.  I have not been able to locate it.  There is a tool set from Koul Tools, but it is almost $400.

https://www.youtube.com/watch?v=RSR-PsOoeqI

Can anyone point me at a less pricey tool, or inform on techniques working with this tube?

Thanks and cheers,

CT

[Leester]

Any chance the tool used to hold brake lines while flaring the ends would work?

[ctaylor738]

Excellent thought.  I have that tool.  I bought an extra meter of polyamide tube to practice with.

Thanks,

CT

[mdsalemi]

Can anyone point me at a less pricey tool, or inform on techniques working with this tube?

Chuck, I’d call/contact the tech support department at Parker. They are one of the leaders and leading suppliers of tubing and fittings used for instrumentation. Perhaps they’ll have a solution for you.

https://help.parker.com/us/en/support

There are others nationally and internationally:

https://sealexcel.com/instrument-tubing-fittings-safe-connection-guide/

https://www.shfinc.com/instrumentation/

https://www.tylok.com/

Maybe the answer is change the fitting?

[ctaylor738]

Michael, thanks for the suggestions.  I did look at a couple of the sites, but didn't find anything in the way of inexpensive tools.

I did order a couple of meters of the polyamide tubing from Authentic Classics, which arrived today.  I clamped the fittings in a vise and followed Lester's suggestion to use my brake line flaring tool to hold the tubing. I then heated the tubing with a heat gun for maybe five second and pushed it on to the fittings without difficulty.

The original line had about 910 mm of tubing which seemed to me to be a bit short.  I used 930 mm of tubing which made the fit easier.

Cheers,

CT

[Leester]

Yay!

[mdsalemi]

Michael, thanks for the suggestions.  I did look at a couple of the sites, but didn't find anything in the way of inexpensive tools.

Wasn't suggesting any of these sites as a source for cheap tools, but rather technical support in the area of industrial tubing for instrumentation. You'd have to call them, or contact them, not surf their website.

What you may have found if Leester's suggestion didn't work is an alternative fitting to barbed, with a compression or other style of fitment.

But if all together now--you hopefully are good to go. Last thing in the world you want is a faulty oil pressure indicator...