I have a 2007 Kobelco Sk170 Mark 8. YM04U1633 I have a slow bucket curl. About 3/4 of the way through curl the bucket will stop...then after a brief pause it will kick back in and curl. I also have a slow to moderate swing speed. As soon as I engage another function both the bucket curl and swing speed return to full speed and full power as long as any second function is being used. For instance if I curl and swing at the same time then my swing speed and bucket curl are fast as normal....If i pull the boom towards me while curling then same thing full curl speed..... Otherwise the machine operates normally other than a repetitive F011 code. The machine has nothing leaking or drooling anywhere on the machine. Engine rpms seem normal. Anyone have previous experience with this? Thanks
Good day Adrtree Its possible that from your description that a couple of possible cause's to that issue - 1. the pump providing the fluid is not getting the correct signal until you use another circuit 2- Some damage in the valve block allows fluid passage to tank until that is blocked by using another circuit. If you post a hydraulic schematic be happy to try and help out some more. Kind regards Uffex
Thanks for the reply....The service manager from the local dealer said that many Mark 8’s will display those exact systems when the engine has a slight change such as a 200rpm drop from nominal value or even a fuel pressure reading being out of Spec will cause the pump to slow down... So many variables and possibilites..... I looked at your site I find it very interesting. Wish you guys were in Georgia in the US. I have a feller buncher, skidder, log loader with saws, excavator, and mulcher out here on a remote forest job and thanks to Corona I am the only operator and mechanic lol. One man show. I do not have a schematic yet I need to order parts and service books for the machine. I just purchased it. Its perfectly usable and running good its just annoying with the issue.
I live in Norway part time town called Arendal as well as the US. We have had alot of help from UK guys before. Shipping cars over to Norway that could not get approved for registration we would send to the UK for your single vehicle approval scheme..... Same with motorcycles. The only solutions came out of Germany with the TUV which is difficult.....or the UK much easier.
The easy way to test: swap 02 connector of "PROPORTIONAL SOLENOID VALVE" (PSV) which are installed on the 02 main pump (swap connector only, don't swap whole solenoid valves)
Good day adrtree We are interested in your issue so please keep us in the loop. Kind regards Uffex
I dont know if anyone is still reading this. Took the machine to Kobelco. They discovered the machine had a new main pump. Different than the stock pump. A Kawasaki pump. They figured out whoever put the pump in had the low pressure sensor where the high pressure switch belonged and they had the hoses criss crossed. They reversed the sensors and the lines and now everyone at the dealership thinks the machine has more power than a new one and it runs perfectly. Thanks for your advice....