Hydraulic hoses - fitting sizes - etc.

[Jeff-C175 7,195]

Mailman brought the rest of my parts today.

 

This Speed-Flex hose is tough stuff!

 

The fittings take a little work to get the stainless braid worked loose enough to get the brass compression 'olive' seated around the PTFE inner tubing.  Them stainless wires are stiff!  and SHARP!  WEAR GLOVES!

 

The vid for installing the fittings was taken down because they used the word "Teflon" in the vid and Dupont's lawyers issued a 'cease and desist' order.  If you want to see how these go together, look at this vid for the 'coated' hose:

 

http://www.anplumbing.com/page/12

 

The 'coated' stuff is the same hose with a clear heat shrink over it, but the fittings install the same.  He makes it look easier than it is!  and doesn't wear gloves!  Maybe by the third or fourth one it will get easier.  I did have a little trouble with the first one I did...

 

Earl's says to cut the hose with a sharp masonry chisel against a block of aluminum, but I found that the Dremel tool with the cutoff wheel works very well.

 

I got the grass cut today so if it's not too god-awful hot in the shop I might start the job tomorrow, should only take a couple hours.

Edited July 21, 2013 by Jeffpicks

[Jeff-C175 7,195]

All done, dry as a bone, no more leaks... well....... except for the VALVE... there IS an ever so tiny 'seepage' from between one of the side sections and the center section on the valve.  I bought the kit to reseal it, but when I rebuilt the lift cylinder all that stuff inside was durn near perfect after 33 years and I wondered why I bothered... not that it was hard to do, I just wondered why if it wasn't broke, I 'fixed' it.  More about the lift cylinder below...  Since the cylinder was in perfect condition, I figured why bother with the valve?  EHHHHHHHHHH! mistake.  So now somewhere in the next couple weeks I need to take the valve out and reseal it.

 

When I rebuilt the cylinder I replaced all the O-rings EXACTLY as it came apart.  On the PISTON, is one O-ring and two 'flat rings' in the same slot.  The two flat rings were next to each other and the O-ring was was on the end.

 

AFTER the thing was all back together and mounted on the machine, I read the rebuild instructions again.  It turns out that the cylinder was WRONG FROM THE FACTORY DAY ONE!  The two 'flat' rings are NOT supposed to be next to each other!  In the slot on the piston should be FLAT RING - O-RING - FLAT RING in that order.  In other words, O-ring should be sandwiched between the two flat rings.

 

It's worked for 33 years that way, so I did not remove the cylinder again and change it to how it should be.  I probably will do that when I take the valve out to re-seal it.

 

The Speed-Flex tubing is fairly easy to work with once you've done a couple fittings.  I didn't use the masonry chisel to cut the stuff but instead used a cutting wheel on my Dremel tool.  Cut through the steel braid with the wheel, then through the PTFE with a razor knife.  I gave up on the gloves, too clumsy, and if you are careful, you won't get stabbed by the wires.

 

So, that's the end of the story...  next project, either new bearings in the deck spindles, or new fuel lines and a carb cleanout.

[JamesBe1 80]

Great info Jeff.  Thanx for sharing your experience. 

I think you're right about not opening up the cylinder again to change the order of the orings.  If it ain't broke, don't fix it.

I've had a couple of spool valves apart in recent years.  They are not at all difficult after having rebuilt cylinders.

 

Deck spindle bearings, fugedaboudit.  Don't wanna fight with them if I don't have to.

[Jeff-C175 7,195]

Thanks James, I hope this thread helps someone in the future...

 

I wanted to mention one more thing I learned about using the ORB to 37° adjustable angled adapters.

 

They may leak if not installed correctly!

 

Referring to this pic:

 

 

Note that there is the threaded portion that goes into the 'device' you are adapting, then the O-ring, then a thin flat washer, then the locknut.

 

In between the two threaded portions is an area with no threads which the O-ring and washer are installed on.

 

When installing these fittings, make sure the O-ring and washer are very close to the outer threaded portion and not pushed up toward the locknut threads.  Then, run the locknut down so it is just touching the washer.

 

Without allowing the locknut to back off, screw the adapter in until the O-ring is being compressed slightly into the chamfer in the tranny/cylinder/valve.  Adjust the position of the fitting and tighten the locknut.  (a little blue loctite on the locknut is a good idea).

 

If you install these without making sure the O-ring is 'near' the threads, what will happen is the O-ring won't be compressed enough in the chamfer and the fitting will leak.

 

And just to re-state something from earlier, MY C175 uses two different size ORB fittings.  The tranny are SAE #6, the cylinder are SAE #5.  The valve uses both sizes:  the supply and return from the tranny are SAE #6 and the supply and return from the cylinder are SAE #5.  Remember that my machine is an early 175 with the Sundstrand tranny, the later EATON models may differ.