backhoe woe

[mikim]

I have a woods 80X hoe on a NH TC45... I've had it about 7 years with no troubles til now. I was digging a trench - put no undue stress on it that I can think of...But the swing left has stopped working. I can swing right under control, but when I swing left it does so out of control and without any torque. Obviously the problem is with the 2 cylinders that do that operation. There are no leaks, and nothing is bent, broken, warped, etc. What can be the problem? Seals inside a cylinder? Which? Is there an easy fix? Getting these things off looks to be a bit of a problem. Once off, how do I determine which one needs repair? My knowledge of hydraulics is limited to "plug this thingy into that thingy and it works" and when it dun't - I'm dun. I took it off the tractor but can put it back on to troubleshoot if need be.

 

[J_J]

You should be able to isolate which cyl is bad by removing the hoses from each and pressurize each cyl to determine which cyl is bypassing fluid.

You could fully extend one of the cyl and and remove the rod end hose and see if fluid can be pushed past the seals.

 

[mikim]

OK ...I kinda get that ...separate 'em and operate one at a time. The bad one won't work. To remove one I have to remove both ...the way they're mounted...Maybe I'll rig some hose off my log splitter to work these cylinders on the bench.

 

[bindian]

Mike,
You say they need to be removed together? Can you swing the bh boom to the right, take the nut off of the left swing rod end bolt at the boom, then swing the boom back to center, remove the bolt, then swing the boom back to the right. When I do this to mine, I have room to remove the gland nut with the rod and rod end. If you can do this, I can't see taking the cylinders completely off of the backhoe. Then you can replace the o ring and wiper ring that is making it bypass internally. My guess is the left swing cylinder.
hugs<<><><>>Brandi

 

[6sunset6]

My guess ,on a rainy sat afternoon, is that the piston came off the rod on the left cylinder. If you do the work yourself ,when you get a seal kit get a new nut as well.

 

[mikim]

Brandi -- You're saying repair the cylinder in place? ... I guess I could try that...the rod end is mounted to the boom with a large drive pin that is held in place with a small drive pin...it might depend on if I can get the clearance I need to drive out that small one. THEN I'd be looking at the cylinder thinking ....gee wonder what's in that thing? I'm going out now to spend the afternoon on a mower...so this whole thing will have to wait til I can get tuit. I have no pressing projects for it so there's no hurry. Thanks everyone for your input. Got a serious hydraulic dummy here. neighbor asked if it could be a valve stuck open? opinions?

 

[bindian]

Brandi -- You're saying repair the cylinder in place? ... I guess I could try that...the rod end is mounted to the boom with a large drive pin that is held in place with a small drive pin...it might depend on if I can get the clearance I need to drive out that small one. THEN I'd be looking at the cylinder thinking ....gee wonder what's in that thing? I'm going out now to spend the afternoon on a mower...so this whole thing will have to wait til I can get tuit. I have no pressing projects for it so there's no hurry. Thanks everyone for your input. Got a serious hydraulic dummy here. neighbor asked if it could be a valve stuck open? opinions?

Mike,
Either I will be going to Manor next weekend, or Rebecca and Chloe will be visiting me. If I go, I'll stop by and give you some words of wisdom. Looking at it will say a lot about being repaired on or off the bh. I do stand corrected. Mine doesn't have a nut either, just a pin with a flange held in place with a small bolt.
Can you take photos and post here? One looking straight down with the bh centered and one with the bh far right. Some from the sides and at angles.
Could be a loose nut. I never saw a nut come off. But I sure have seen trashed piston o rings and backup/wiper rings.
hugs<<><><>>Brandi

 

[mikim]

Mike,
Either I will be going to Manor next weekend, or Rebecca and Chloe will be visiting me. If I go, I'll stop by and give you some words of wisdom. Looking at it will say a lot about being repaired on or off the bh. I do stand corrected. Mine doesn't have a nut either, just a pin with a flange held in place with a small bolt.
Can you take photos and post here? One looking straight down with the bh centered and one with the bh far right. Some from the sides and at angles.
Could be a loose nut. I never saw a nut come off. But I sure have seen trashed piston o rings and backup/wiper rings.
hugs<<><><>>Brandi

OK -- you just gave me another "honey do" ....I got one woman doing that to me....really need another???? ...I'll have to wash it first then take pics. Next weekend - we'll be gone on saturday but should be home sun & mon. I think I have enough to keep me busy at least 1 week without needing the hoe... The biggest problem with putting it on the tractor to work on it - is then can I get it off to do other stuff? Probably.....as I think about it....

 

[boggen]

hydraulic dummy here. just wondering, if you checked your hyd oil levels, and if it ever got low? wondering if there is some trapped air in the hyd cylinders. or at least one of them. and needing to work it out.

are the swing cylinders, double acting hyd cylinders or single acting hydraulic cylinders?

double acting = 2 hoses come off of each hyd cylinder. (3 hoses total, 2 hoses goto a valve, 1 hose connects both cylinders together)

single acting = 1 hose coming off, (2 hoses total).

have you double checked the linkages between valve and lever / joystick. to make sure they are adjusted correctly / tightened?

no idea what valve the swing uses. just wondering if there may be a problem at the valve, such as a spring? or relief valve? that either has gone bad or is getting stuck open/closed?

==================
condoms, of all things, can be easy way to place on end of hoses, and like, to keep dirt and crud getting into things as you disconnect stuff to get in were ya need to get to. some rubber bands, or twisty ties (bread ties) or even zip ties can be used to secure the condoms.

single finger glove (condom for a finger) band-aid isle / area of local stores. can also work. might be a tad easier, for the short stubs / male threads on the valves. after you take the hoses off.

"line wrenches" you have your normal U and O shape box end wrenches, that ya see at every tool store, but then you have "line wrenches" that are more of a C shape, they slip over the hyd hoses, and then slide onto the nuts. it gives you a bit more gripping on the end of the hoses, without wrench slipping off.
--other words a "line wrench" is mix between a U and O shape box end wrench

be extra careful, you will be letting air into the backhoe system, and stuff will not hold at all, make sure you let everything rest down on the ground and pressure taken off of everything, before ya get in there.

if you end up dismantling a hyd cylinder, be careful, the piston/rod could suddenly come loose and shoot out. make sure you stand off to the side as ya work on them. a lot of risk comes from compressed air. but still a risk factor without compressed air, due to overall weight, and how awkward it is to grab a hold of some of the items.

 

[mikim]

Today's plans got sidetracked so I figgered I'd try to see if I could get a handle on this thing. I put the hoe on the tractor then removed the pins holding the ends of the swing rods on, (pic1) then started the tractor thinking I would then move the stick back and forth and see which one wasn't moving....BUT as soon as I started the tractor I heard woosh - rattle rattle..one of the rods came flying out of it's cylinder volunteering to be the bad one. I got less than a gallon of fluid spilled before I cut the motor. You'll notice (pic2) that it has a bit of curvature and the threads on the end are stripped.....easy enough to figger I need a whole new assembly. Took the whole thing off the hoe (pic3) they are trapped via top and bottom bushings between the blue frame and a black cross member. Hope I can get them torqued back on as tight as the bolts were. I had to use a breaker bar and cheater to break the nuts loose. Guess I won't be able to over torque 'em leaving off the cheater. Being as incompetent a mechanic as I am ... I'm pretty proud of myself getting this far. Course it helped that the errant cylinder jumped out at me. Now all I gotta do is order a new swing cylinder and switch it out..in the meantime the hoe is in the middle of my shop on blocks....oh well.