Certain funtions are slow on 220LC-V (left track drive, etc)

I recently purchase a Daewoo 220LC-V (2000 model) and the previous owner stated that one track was slow after changing a hose. He stated that the oring came apart and he thinks some of it may have went into the system. (Not sure if this is true or not) Anyway, the left track drive is slow, along with the boom up function. If I pull the boom up function, the left track drive goes to normal speed. Also, when first picking up the boom, the engine bogs down so you have to ease into it the first time after letting the boom sit still for a couple of seconds.

Does anyone know where I should start looking. Does this sound like a possible restriction from the piece of oring he mentioned? Where should I begin to look for obstruction etc.


Any information would be greatly appreciated.

since the former owner told you it happen after he changed the hose...
...it seem to be a restriction somewhere! did you check if there is a restriction on the hydraulic motor..a clogged screan?

We are going to start pulling hoses tomorrow. Is the screen located at the intake fitting on the pump or inside?


Thanks for any help.

so...did you found the problem?? any news?

No luck yet. Currently pulling apart the relief valves to see if anything is hanging up or there is an obstruction.

O rings dont blow in, they blow out, you may have a pump stroke problem , or if it has dual pumps one may be toast.

Hoping that a pump failure is not the case. The previous owner told me he was repairing a leaking o-ring and it came apart when they removed it and some of it went into the line (???)

The machine does have piggyback pumps. When you first go to raise the boom, it overloads the engine really badly. After you give it a second, and ease into the controls, it clears up as long as you keep operating the machine. Stop running the controls, and it will bog again when you first start to use certain functions.

either the o-ring have plugged somewhere in the line or you have a swash plate trouble...

landworks, couple of questions:
is the swing working fine or it is slow?
is the bucket ok?
when you load the arm function the engine stalls?

Manual Naut....thanks for the reply

Yes, the swing is very slow. The bucket may be a little slow but not as noticable. Left track is slow. Right is ok. When you first go to pickup the boom, the engine stalls. If you slowly ease into the boom up function, you can get it to start working. Then it is ok as long as you don't stop using functions for very long. When the left track is slow, if you use the boom up function, the left track will go to full speed. Any help would be appreciated.

hi, jon. check the email i just sent you

I know this is an old thread, but did you get your slow left track figured out? I have almost identical problem with ex300. Could you please let me know if you got this resolved and if so what was it. Any help would be apreciated, thank you.