04 A300 Hydralics

[cats7cc]

Have a 04 A300, when we lift the arms up they go up fine with no resistance or hesitation. As soon as they are up in the air they fall right back down. The bucket positions fine. Can anyone point me in the right direction. I've done a search on hear and didn't find much. Do I possibly have something as simple as a bad o-ring somewhere or do I have something going on with the electronics or something else?

 

[cats7cc]

machine has 3,000 hrs

 

[antfarmer2]

machine has 3,000 hrs

Make sure your aux hydro is not stuck on then look into resealing your cylinders

 

[jerry]

Make sure your aux hydro is not stuck on then look into resealing your cylinders

I would guess a load check valve is sticking open but cant tell you where to locate it.

 

[Tazza]

I would guess a load check valve is sticking open but cant tell you where to locate it.

The load checks are mounted into the control block.
How fast do the arms drop back down?
It's not aux sticking, that would not make the arms fall back down, it removed power from the hydraulic system diverting it.
I'm wondering if it could be bad ram seals.

 

[antfarmer2]

The load checks are mounted into the control block.
How fast do the arms drop back down?
It's not aux sticking, that would not make the arms fall back down, it removed power from the hydraulic system diverting it.
I'm wondering if it could be bad ram seals.

I stand corrected but trying and learning

 

[OldMachinist]

I stand corrected but trying and learning

It does sound like a bad load check valve. May just have something stuck in it.
By the way year means nothing on a Bobcat. All info, diagrams and parts are serial number driven.
So with a serial number I could post a diagram of the control valve to pinpoint where the lift load check is.

 

[Bobcatdan]

It does sound like a bad load check valve. May just have something stuck in it.
By the way year means nothing on a Bobcat. All info, diagrams and parts are serial number driven.
So with a serial number I could post a diagram of the control valve to pinpoint where the lift load check is.

I would look at the cylinders, one is leaking internally almost guarantee. A possibility is the the emergency boom lower vavle is bypassing. The control vavle is the last place I would check. A leaking port relief vavle could cause the problem, but not a load check.

 

[Tazza]

I would look at the cylinders, one is leaking internally almost guarantee. A possibility is the the emergency boom lower vavle is bypassing. The control vavle is the last place I would check. A leaking port relief vavle could cause the problem, but not a load check.

The boom lowering valve, i never though about that. It is another very good spot to look. They can rust up over time and stick/leak.

 

[cats7cc]

The boom lowering valve, i never though about that. It is another very good spot to look. They can rust up over time and stick/leak.

S/N is 521111504. A diagram would be great to refer to if you don't mind getting me one. That way we know exactly where to tear into this thing after we eliminate the lift cylinders also.

 

[OldMachinist]

S/N is 521111504. A diagram would be great to refer to if you don't mind getting me one. That way we know exactly where to tear into this thing after we eliminate the lift cylinders also.

 

[cats7cc]

Thanks guys! I think we have it figured out and have narrowed it down to the lift cylinders. Going to rebuild them and see what that does. On another note, In need a a new heater core. Is there anywhere we can get one aftermarket or do we need to just break down and order through bobcat? Kind of spendy through them.

 

[Bobcatdan]

Thanks guys! I think we have it figured out and have narrowed it down to the lift cylinders. Going to rebuild them and see what that does. On another note, In need a a new heater core. Is there anywhere we can get one aftermarket or do we need to just break down and order through bobcat? Kind of spendy through them.

A radiator shop should be able to repair if it is not beyond repair.

 

[cats7cc]

A radiator shop should be able to repair if it is not beyond repair.

mmmm.....long story short, took it out to clean up and after cleaned up laid outside on top of the dumpster. Needless to say the garbage man came that day. So, now we need a new one.

 

[antfarmer2]

mmmm.....long story short, took it out to clean up and after cleaned up laid outside on top of the dumpster. Needless to say the garbage man came that day. So, now we need a new one.

If you remember the size find a sub or a after market