Replacing a swing cylinder hose on my backhoe

skipro3 · Feb 27, 2020

I have a Montana 4wd tractor with a 3 point hitch mounted back hoe. One of the hoses to the dual swing cylinders is leaking. It is the hose that goes to the OUT port on the manifold of valves. (Sorry, I'm not too versed on this) It is pressured up via a PTO pump that has pressure input to the manifold on the IN port and return through an oil filter on the OUT port. Meaning I do not know if the OUT port hose that is leaking is on the high pressure side or the return side of things. I think it's the return side because it drips and doesn't spray when utilized.
Anyways, the leak is at the cylinder. There is no room to get a wrench on both the hose and the union at the cylinder, and even if there was, there's no room to rotate the wrench. It's a trunnion style cylinder, so I thought I could just pull the pin on the ram and swing it out to get access but there's just too much interference with all the other hoses running around there.
How the heck can I get to the hose fitting so I can replace the leaking hose? It's a 3/8" x 20" NPTM on both ends.

As background, the high pressure hose from my PTO sprung a leak I repaired today with a hose from Tractor Supply; 1/2" x 38" NPTM on both ends. No problem doing that. I'm fairly mechanical, but other than the complete disassembly of the entire hoe, I do not see how to get to the fitting. The trunnion cylinders are captured in there between 2 horizontal plates that hold a whole lot together.

If I take it into a shop for repair, what could I expect to pay to have them replace the hose?

tookielee · Feb 27, 2020

A picture might help

davedj1 · Feb 27, 2020

What I have done and it may or may not work for you is once I get the free end loose then I cut the hose and get a box end wrench over the nut and turn it a little until it's loose enough to spin out by hand. Then thread the new one in and tighten a little at a time, I have also had to remove other hoses to get to a connection, no fun but actually faster in the long run.

skipro3 · Feb 27, 2020

Thanks for the replies. I'll take some photos of both the tractor area in question and the parts diagram showing the assembly to make the photos a little clearer. The thing about the photos is everything is painted black from the factory; black cylinder buried in black plates.
For a visual, the ram is trunnion mounted with rather large plates mounted above and below for the pivot holes. This is what makes it hard to even get fingers on the fitting, let alone a tool. The valve assembly sits on top of the upper plate and to add more misery, this is powered from a PTO hydraulic pump with a 5 gallon tank directly behind the swing cylinders. In order to take the tank off, I would have to take the backhoe off the tractor (It's 3 point mounted) and that requires hydraulics functioning to do. If I had a gantry crane/hoist, That would help support while I'm disconnecting the tank and all the steel plates that hold this all together. I thought I MIGHT be able to get in there by disconnecting the ram arm, lowering the stabilizer leg on the that side and pivoting the ram to an opening exposed when the leg is about half way down. But there's so many hoses packed back there that the cylinder can't rotate nearly enough.
Oh well, My guess is that I'll either have to take the whole thing apart to replace a hose I can buy from Tractor Supply for $11 or pay a mechanic a few hundred to do it for me. For now, it works, just leaks when I'm swinging the hoe to dump my bucket. Since it's just one of the swing cylinders, I could just disconnect this one, replumb the remaining one as a single and not use the bucket to push the dirt back into the hole I've dug. It probably would still push some dirt, just not the work of two.

electrycmonk · Mar 4, 2020

So I have a couple questions for you. Can you share what make & model of backhoe this is? I recently got one and had been building a list of potential units for my cub cadet. From Bradco, woods, Kubota, ARP, ford, mahindra, and Century (Kelley and sons). I ended up getting a Kelley & Sons Century series 20 BH. In the process I learned from web pics that it came in different color patterns and with a few different variations to the final design.

Maybe your cylinders and connections are similar position and shape to mine?

So here is a link to my thread regarding the cylinder question I have - I made the post tonight and i figured its easier to just post a link then drain bandwidth with the same pictures in another thread. Fair enough?
https://www.tractorbynet.com/forums/hydraulics/422539-cylinder-repair-suggestions.html

BTW I figured out that Northern Tool has a larger selection of fittings then Tractor supply, so maybe you can have better selection to build your solution for easier future care & maint?
best of luck.