Air in Backhoe Hydraulics

[Unk]

Jerry,
You right, for the time and little money I'd have in it, I'll get it to a hydraulic shop and eliminate that as a problem...

BUT....

First, on John's recomendation I think I will do an extensive look see on the suction side...

John, are you also suggesting a restriction on the suction side (I.e.pluged strainer) with out pulling in air specifically....could possibly cause the cavatation/massive bubbling? This shows you how little I know about hydraulics.

If I have to replace the pump can any one recomend a source, quality brand at a reasonable or great price....other than starting cold with an internet search I wouldn't have a clue.

John, I'm not sure about the where and where the water came from; I bought thr rig used last year from a neighbor in summer and it sat till I picked it up in Janurary. But, Thanks for the tip on the water absorbing filter and changing before winter.
Thanks Again All,
Unk

 

[638]

You will NOT suck air on the pressure side of the system. That being said, if the suction screen is plugged, you could be pulling in air around the pump shaft seal or at any slightly loose fitting on the suction line.

ron

 

[Unk]

Ron,
Any possibility the relief valve on the valve body would cause something like this I.e. obstruction, malfunction, way out of adjustment?
The pressure side to pull air without leaking at 2500psi didn't make sense to me either...
I'm going to focus on the suction side and have the pump checked out but, I just can't help but wonder.
Ya' gotta have respect for anyone who does hydraulic work...
Thanks All,
Unk

 

[john_bud]

Ron,
Any possibility the relief valve on the valve body would cause something like this I.e. obstruction, malfunction, way out of adjustment?
The pressure side to pull air without leaking at 2500psi didn't make sense to me either...
I'm going to focus on the suction side and have the pump checked out but, I just can't help but wonder.
Ya' gotta have respect for anyone who does hydraulic work...
Thanks All,
Unk

NO possibility of bubbles from the pressure side. As 638 said, if the strainer or filter is clogged the pump can generate a lot of vacuum and cause air intrusion from places like pump seals etc. Get some spray oil (WD40 if it's all you have, but a thicker oil will be better) and spray it around the pump shaft, housing, hoses etc. Make a note if the sounds change.


Surplus center has hyd pumps.

Surplus Center - Hydraulic Equipment Electric Motors

 

[mikeykubota]

Sorry to post on another person question. But i am not sure on how to post a question I have a cub cadet 407 backhole attachment on my kubota tractor. and it has always work great But the other day I blew a cylinder on my backhoe. I change the cylinder and everything work great again. The next day went to use it and the all of the cylinders on the backhole was real slow. Talk to a lot of people about bleeding the air out everbody said it should come out by it self. Today i went out to see if i could get it to work and none of the cylindes was working except for the outriggers would go down real slow but they wont come back up, the front end loader on the tractor works great anybody have any idea what the problem could be

 

[J_J]

Those post are from 2007

You could start a new thread if you want to.

Post in this section. Cub Cadet Yanmar & CUTs on the forums page.

However,

Re-check the QD for the BH.

If you have a hyd gage, you will know if the QD's are not connected correctly by the back pressure reflected on the gage. With all valves in neutral, should be no or very little pressure on the gage.

In most cases, if air is in a cyl, it will eventually work itself out by you cycling the cyl .

If the cyls keep getting air, then you probably have a suction leak and you are aerating the hyd fluid . You need to find the leak. Try tightening all the clamps.

Look in the tank with a flash light and see if there are bubbles in there.

If the tractor has not been cranked up in a day or so, the air in the tank should have dissipated, so start the engine and look in the tank ans see if new air bubbles are being developed, and if so, then there is a suction leak.