Loader piping fittings JIC with tapered threads?

[peakbagger]

One of the fittings on my loader snapped today under load. Its on one of of the boom cylinders that lifts the entire loader up. It was under heavy load, and looks like a fatigue failure. I have kept this system stock and have not removed the "hidden" pressure reducing valve on this system so it was stock pressure (unless the hidden valve is not working). I looked up the part number and sent an inquiry to EI and they responded quickly that its mongrel part. Not mercedes and nothing they have in stock. Its an adaptor 90 degree elbow. The end that screws in the cyclinder side is flat faced straight thread backed up by an o ring and nut. I found that in various fittings manuals but the other side looks just like a JIC straight thread cone fitting but unlike all the fitting manuals the threads are tapered. I went down to a local parts store and they had the right size JIC fitting in a straight adapter. Despite the tapered thread on the originals, the JIC screws right in and appears to seat.

They didnt have the adaptor elbow but will order one in. I am going to give it try but has anyone else run into this odd variation of what looks to be a JIC fitting but with tapered thead?

 

[glcaines]

Have you tried contacting Schmidt?

 

[peakbagger]

I did not contact Schmidt. I did find out that the odd thread is JIC thread that should be straight thread with the same pitch but is distinctly tapered on the male cast fittings on the SEE. The net result was I bought a standard fitting with a straight female JIC thread and the existing tapered fitting worked (no leaks). The actual sealing occurs via a conical seat rather than the threads so as long as the pitch lines up I guess a bit of slop in the thread clearances is okay.

 

[glcaines]

I see that there are some of the fitting you need for sale on Ebay at $10.00 each, new, although he does want $5.00 for shipping. https://www.ebay.com/itm/DAIMLER-00...242472?hash=item36529ccfa8:g:2vcAAOSwY4pdVa0V
Gary

 

[peakbagger]

Thanks but those are not the ones. I saw those. The ones I needed have external cone seat (male) on the horizontal thread and am O ring with backing nut on the vertical thread. The elbow screws into the cylinder until the elbow is int he right place then the backing nut behind the O ring is tightened to seal up the elbow in the correct rotation location.

Surplus Center does have the right ones for about the same price but I bought mine through my local parts store.