B2775 hydraulic snow blade leak

[texasranger556]

I don't think you can use a crossover relief on one double acting cylinder. The volumes on the base and rod end are different, so you'd cavitate the oil one way, the other way there's no place for the oil to go.

 

[Dave M7040]

I don't think you can use a crossover relief on one double acting cylinder. The volumes on the base and rod end are different, so you'd cavitate the oil one way, the other way there's no place for the oil to go.

You are likely correct.
I did say I had no experience using such valves and I accept your uneven volume point.

Without knowing the history of the plow before it was put on this owner's tractor adds a level of uncertainty in diagnosing the cause.
It has trip springs but are they too tight.
Are there mechanical stops on the blade so the cylinder is not taking the loads at the ends of the push rod motion in both directions.
What hydraulic pressure is his tractor operating at compared to the design pressure of the cylinder

I don't sense this owner is one to be bashing into things.

If he gets a new cylinder from his dealer then should the matter happen again..............

Dave M7040

 

[texasranger556]

The spool valve may have a work port relief valve that could be adjusted, but unlikely. Kubota probably just depends on the trip springs to limit stress on the cylinder and frame, and like you say they might be a bit stiff.

For the snap ring to wear the groove like that it likely wasn't seated all the way to start with. Paint in the groove, etc. If it was mine and the dealer doesn't cover it I'd clean up the snap ring groove, add some sort of spacer and move on. Basically what has already been suggested.

 

[NEPA guy]

As I understand your use, you are often swapping a snow blower for the blade and each time this happens you have to disconnect and reconnect two hydraulic lines.

Yes, I often swap between the snowblower and the blade as the conditions call for it. When the snow isn't too heavy and/or its cold enough, the blower is much faster and easier to work with.

Quick couplings can be very difficult to seat properly. Some owners with loaders have a very hard time because as the FEL settles a little after it is off the tractor, the pressure in the hydraulic lines on the loader build up a bit and getting the quick connects to fully seat is impossible. In my opinion you failed to have the cylinder retract coupler fully seated.

That's very possible. I only learned last year about the FEL pressure buildup after it sat in my garage over the winter. I had to unscrew the coupler to let some fluid out before I could reattach it. I thought that if the coupler was seated properly it wouldn't leak.

The milky fluid is likely just air from being sprayed out of the end of the cylinder as the cylinder end came off.

Thats makes perfect sense, thanks for clearing that up.

What do you do before removing the hydraulic lines and swapping implements. Are you doing this swap with the tractor running?

My neighbors have tractors and one of em has been giving me some tips here and there. He told me about wiggling the lever back and forth and up and down to relieve the pressure. I do it everytime after I shut off the tractor, I put the empty dolly under the blower before I shut it off, wheel it out of the way, then roll the blade over, attach it to the male hitch, lock it in and attach the hoses, sometimes it seems easier than other times, but I thought I was getting good at it. Usually under 10 minutes. I'll try to pay closer attention in the future. .

It turns out that attachment for the snow are covered under warranty for 2 years, so I just made it by one month, so thats good news. I spoke to my dealer and I'll drop it off the entire implement. They didn't want me to remove the cylinder so they could test it after they reinstalled it.

Thanks for your help. I really appreciate it.