Mx5100 power steering hoses. What fitting type?

[LD1]

Need the assistance of the TBN brain trust.

Got a weeping hose on my mx5100. Weeping several places through the hose.

The hose ends are labeled SF-PF-04-14.

Googling seems to lead me to "parallel pipe female thread union" as the type.

They have a 30 degree inverted flare. Is this just another fancy name for NPSM?

Here are some pics



I have some 1/4" NPSM adapters and they seem like the right fittings. They thread on and tighten down sufficiently (no longer swivel). Hex size for the wrench is different but who cares.

The two hoses are listed under different part numbers, but have the same ends. Nearest I can tell is there is only maybe 1" difference in length.

Messicks prices are $86 and $113 each. Seems a bit steep for a simple 60" long 1/4" hydraulic hose with NPSM ends. Which I can make for $20 or less a price if they are indeed NPSM.

 

[oldnslo]

I would suspect they JIS 30 degree seat metric thread.

This is a common Japanese connection

 

[LD1]

JIS has an inverted flare? I haven't ever used jis but thought it was just like JIC only with different threads and different seat angle

 

[newbury]

From Discount Hydraulic Hose back in 2010:

Everyone here has it right. The NPSM (National Pipe Straight Mechanical) is a female pipe swivel, and it should seal with your male NPTF (National Pipe Taper Fuel) as long as the male has the internal 30ｰ chamfer. Almost all NPTF fittings I've seen have this chamfer, but some NPT fittings do not.

In case I just confused someone by mentioned NPTF and NPT in the same sentence, here's the deal. NPT and NPTF have the same tapered threads, but NPTF is a dryseal, intended to seal without the need for thread sealant. I'm not sure this matters a lot, since everyone I know still uses the thread sealant anyway.

 

[oldnslo]

Yes there is a JIS 30 degree inverted flare. The M14 x 1.5 is very similar to 1/4" NPSM. I believe discount hydraulic hose website has a link for identifying threads.

 

[LD1]

The major diameter of the threads were 0.520, which closer matches the 1/4" NPSM than a 14x1.5.

Not saying it ain't metric and JIS inverted. But the 1/4" NPSM threaded right on just like the hose end and locked down tight with no signs of stripping like it were slightly wrong.

I think I am gonna give it a shot

 

[LD1]

Just looked at dhh's fitting ID guide again. Nothing at all about an inverted JIS. In face, looking at Parker catalogues, dhh, and other places, the only thing I am seeing with a 30 degree inverted flare is the npsm

 

[oldnslo]

Can you hold the male hose end next to the NPSM fitting to see if the threads are the same pitch?

Metric is 16.9 threads/ inch
NPSM is 18 threads / inch

Close enough it may or may not matter.

Possible the JIS has been phased out. Used to be common 10 years ago.

 

[oldnslo]

Did some research and could also possibly be BSPP 1/4-19 is .520 OD
If this link works it for a thread identification hand book. pages 34 & 36

http://www.eaton.com/ecm/groups/public/@pub/@eaton/@hyd/documents/content/pct_472120.pdf

 

[LD1]

I didn't have much time today to look into it as I had to leave for work. I just wanted to get length to make hoses. I can buy whatever adapters later, but only have access to the hose crimper at work.

So I made hoses with 1/4npt ends and have NPSM adapters. If they don't work, hoses are still good just need the right adapters. I'll take a better measurement and put my thread pitch gauges on it tomorrow.

This may indeed be metric or bspp, but may be a case where NPSM "will" work. All the threads have to do is tighten down. The 30* cone is the seal, and that's what NPSM is. So if the threads are a pitch off, or a few thousandths difference in diameter, don't much matter if it holds. But I ain't paying Kubota $100 for a crappy hydraulic hose.