LX885- Air leak in hydraulic system?

[eastcoast86]

The LX885 that is here at work has been acting up recently. The boom lift circuit has become extremely jerky and it is difficult to operate without making abrupt movements. It is most noticeable in this circuit but the rest of the hydraulic system also seems to be feeling a bit out of sorts. The loader recently lost a significant amount of fluid through a bad auxiliary coupling and the system was likely run for a few days with very low fluid. I changed the bad coupling, hydraulic fluid filter and refiled the hydraulic reservoir. The symptoms I described seemed to start after I changed the filter and refilled the reservoir. I was wondering what you think about these systems. I am inclined to guess that air must be present in the system, either from a continuous leak or from running on such low fluid. The boom also seems to be a bit bouncy when loaded. What do you think? It is also possible that water was allowed to enter the system. It has been raining frequently around here and I noticed that the breather cap on the hydraulic reservoir has a crack in it. Is there any way to drain the hydraulic fluid. I would like to ensure that no contaminants are circulating in the system. I have not seen a drain plug like there is on the LS185.B. If anyine had any advice on how to drain and flush the system I would greatly appreciate the advice. Thanks for the help.

 

[Tazza]

Check the oil colour, if its milky it has water in it.
How long has it been jittery? if its only been a day or 2, give it a little more time to bleed out. You will have gitten air in the system when you changed the filter, not enough to matter, but if it ran dry with the aux coupler you will have a fair amount of air stuck, It will take time, but it should purge.
I have always drained my system by running at idle and operating the aux hydraulics to squirt the oil into a drum. WHen it starts to spit or foam, shut down, re-fill.

 

[Earthwerks Unlimited]

Check the oil colour, if its milky it has water in it.
How long has it been jittery? if its only been a day or 2, give it a little more time to bleed out. You will have gitten air in the system when you changed the filter, not enough to matter, but if it ran dry with the aux coupler you will have a fair amount of air stuck, It will take time, but it should purge.
I have always drained my system by running at idle and operating the aux hydraulics to squirt the oil into a drum. WHen it starts to spit or foam, shut down, re-fill.

I'm not convinced that your problem will go away. I have run my Ls185.b out of fluid many a time and it always returns to normal as soon as the fluid level is restored.
IMHO (based on experience and what you stated), what has happened is you have wiped out the gear pump. You may be able to have it rebuilt, but it might be better to just buy a new one.
The jerkiness is from air alright--pump cavitation due to the pump not making pressure. Cavitation from this or lack of fluid which leads to cavitation, will destroy a gear pump. Luckily, IMHO piston (drive) pumps are more able to tolerate no fluid.

 

[Tazza]

I'm not convinced that your problem will go away. I have run my Ls185.b out of fluid many a time and it always returns to normal as soon as the fluid level is restored.
IMHO (based on experience and what you stated), what has happened is you have wiped out the gear pump. You may be able to have it rebuilt, but it might be better to just buy a new one.
The jerkiness is from air alright--pump cavitation due to the pump not making pressure. Cavitation from this or lack of fluid which leads to cavitation, will destroy a gear pump. Luckily, IMHO piston (drive) pumps are more able to tolerate no fluid.

^^ good point, you may want to get the pump flow and pressure tested, then you know where you stand.