Case/Davis trencher backhoe

[DavidBarkey]

Good eye . Yes they sure do look like that . Just need to source the right type and size hose .
@Eugen I have done these before . i can walk you through the dos and don't if you like .

Dave, do you think the fellow in Hillsdale might have the right hose?

I would have too see a sample of the original hose . Anything is possible . PA might ,Simcoe Hose & Hydraulics, or Omniflex all in Barrie . On of them will have what you need . Do you have a chop saw ?

[thebuildist]

I do understand now.

According to DiscountHydraulicHose.com, SAE 100R2 reusable fittings are designed specifically for SAE 100R2AT hose. Full stop.

So if you can buy 100R2AT hose, then you fittings are designed for it.

Around here I can buy it at TractorSupply (TSC.COM), if you buy one of their generic "County Line" 24/36/48/60/96 inch hoses, they're built up using SAE 100R2AT. I just looked at them this weekend, as it turned out.

And they're pretty affordable, at least for around here.

$20 for a 36" 3/8 hose, $32 for the 96" version, sliding scale prices in between.





Bob

[thebuildist]

Any chance you can measure those thread pitches for me? I might need to manufacture a couple of those wiz-bang things.

Bob

[RoamingGnome]

@Eugen - My suggestion would be to call a local hydraulic shop and know a) your max Hyd system pressure, b) your inner and outer hose dimensions c) what fluid is going through the hose... they should be able to match up bulk one or two wire hose for you and give you as many feet as you need - for cutting small diameter hoses a zip cut works great, just make sure the ends are cut to a nice clean 90 degrees - and make sure to blow out the inside of the hose before putting the ends on. re-useable fittings are actually fairly common in lower pressure applications - under 4000 psi - ran into them on scissor/manlifts, smaller tractors and pilot or servo control hoses on bigger excavators.

[Eugen]

Any chance you can measure those thread pitches for me? I might need to manufacture a couple of those wiz-bang things.

Bob

Here you go. The thread on the inside of the sleeve is left handed, and is not 60 degrees even, it is oriented like pike teeth to bite into the hose so it does not pull out easy. The depth of that thread seems to be 0.05.

Here's a mold of the inner biting thread using play dough.

[Eugen]

I would have too see a sample of the original hose . Anything is possible . PA might ,Simcoe Hose & Hydraulics, or Omniflex all in Barrie . On of them will have what you need . Do you have a chop saw ?

yes, I'll bring a piece next time I come by.

0.66 inches inner diameter of the teeth threads on the sleeve. The outer diameter of the part that goes into the hose is 0.55 inches. So the wall of the hose will be pressed in between (0.66-0.55)/2 = 0.055 inches. Now, the wall of the 100R2AT is (0.75-0.375)/2 = 0.1875 inches.

So a rubber/steel sandwich that is 0.1875 thick gets compressed in a space of 0.055 inches where each tooth of the thread reaches in, with parts of the rubber squeezed within 0.105. Might work just fine with 100R2AT. famous last words eh?

My other thinking is that reusable fitting made specially for the military would not be so easy to find.

Wish I had a fitting made for the 100R2AT to measure it.

[Eugen]

Ok, I think I figured out how they used this thicker hose. They sliced it. Had this suspicion and opened one more fitting, carefully. The little dust that came out could not have been all the outer rubber that got squeezed.

Look at the thickness of the outer layer.

[FUTZ]

I've never been a 'Hoser' (Canadian pun); some of those hoses had to be skived (not sure of spelling); meaning you had to take off the outer cover, where the fitting connects. Were the old hoses skived?

[FUTZ]

Okay Eugen, your post just pop up when I posted, and yes looks like those hose end were skived.

[FUTZ]

Looks like 2-wire hose. So all you need is two wire hose, skive the end and your good to go. You will know if it doesn't work, the oil will squirt out