Komatsu swing problem

[EZ TRBO]

Having an issue with my PC220LC-6 excavator. When you swing to the right it will go a short distance and STOP dead. The quicker you are swinging the further it goes before it "Locks". I swaped relief valves in the swing motor to see if it did it the other way but same thing happend. Wondering if it is in the swing motor itself or on the main valve body. Any help or other ideas would be wonderful.

Trbo

 

[special tool]

Sounds like its not unlocking the swing BRAKE.

 

[EZ TRBO]

Sounds like its not unlocking the swing BRAKE.

The swing brake locks onto the large gear in the turntable and I belive that if it was doing that it would do it both directions and would not be able to swing at all. If i pick up speed I can swing almost 90 before it stops. It is acting like the a valve on a race care that you use to shut the left front brake off. We are going to check the main valve, but will recheck the swing brake to make sure its NOT that.

Thanks

Trbo

 

[MKTEF]

I would have checked the brake more in detail.
Normaly they have springs engaging the brake when pressure is lost.

Sounds like it gets its short "shock" of pressure, and then the pressure disapear.
Pressure then drains slow, so you get more when doing a fast sving.

Bet there is a valve/ sort of T/block, connected to both directions pressure and to the brake.(might be controlled by the pilot pressure)
That block/T might need some attention, and be the problem here.
Follow the hose from the brake and see what u find...

I'll have a look at our 210-6 tomorrow and se what i find.
Maybee a short glimse in the repair manual too..

 

[ben46a]

Does it always stop in the same spot? Kinda sounds like a chunk of tooth or debris locking it up.

 

[EZ TRBO]

Does it always stop in the same spot? Kinda sounds like a chunk of tooth or debris locking it up.

No not the same spot, it does it when going slow every few inches and faster you travel the further it takes before it does it. Such like a valve closes at the same speed each time but when traveling slower it stops in a shorter distance.

But now I really could care less, after some "OTHER" things happened today that I wnt' go into detail about I loaded the machine up and took it to the dealer and brought back a rental unit. Hey its only money.

Trbo

 

[palacemasonry]

i'am having the same problem with an pc200lc-7 when swing to digg it stalls and engine shuts off , i got a technian out but the machine plate says it an pc200lc-7 but when ordering parts its an pc200lc-6 engine any one have this problems .

 

[Bigstevex4]

There is a pressure switch for every function for idle up & with the swing it unlocks the brakes there are a bank of them behind the cab swap right for left then try it. simple fix. not a common problem but easy to start with.

 

[T_Gunn]

The swing system is equipped with a double counterbalance valve which provides dynamic braking as you stop swinging. When the house comes to a complete stop, a static failsafe brake is spring applied. The failsafe brake is spring applied, hydraulically released. In most counterbalance valve bodies there is a shuttle valve which moves over and applies hydraulic pressure to the brake to release it in when the operator starts to turn the house. I would check the shuttle valve. The spring that holds the shuttle ball in place in the one direction may be broken and jammed or a piece of dirt may be preventing the shuttle ball from moving.

 

[MrKomatsu]

EZ.....

one or both directions...?

 

[MrKomatsu]

i have seen this problem before a few times...

 

[MrKomatsu]

what is the sn#.....EZ.. i got your testing and repair for this prob....

 

[EZ TRBO]

Thanks Mr. Komatsu, would have helped last october. Had our serice man come out and he was just going to switch some lines to see if it did it the same both sides. While doing so he found a bad wire rubbing on some metal and fixed it and after seeing what it controlled we figured out that was our issue, not a hyd issue rather electrical. But thanks again for replying.
Trbo

 

[fyfebrij]

Hello, i'm having the same exact issue. when ONLY swinging a short distance, the house will lock. However, if you pull a different function at the same time as a swing, it will not lock the house. Has anyone fixed this problem? PC200-6. Id appreciate any help!