Hi, I have a D6C 69J dozer and after a couple hrs work the blade starts acting weird. Before I start work i can see the hydraulic tank sight glass is about half way and the blade starts getting stiff more so the left ram than the right. If I remove the cap on hydraulic tank slightly oil will pouring out the cap. If I shut engine off with blade raised then try to lower blade it doesnt go down with gravity but it used to be able to ? Rippers seem to work fine and can lower easily with engine off . I removed both hydraulic filters in the tank today to see if it made any difference and the symptoms are the same. Even putting blade in float it wont lower with gravity when hot. Im trying to figure out why the oul level raises soo much when hot that it will be right at top of tank. Hard to operate like this as the blade has a fair bit of wear in the links and one side of blade wants to stick tighter than other. What can I check? Its been slowly getting worse as time goes on. Hydraulics can raise front and rear of machine off ground at idle either hot or cold. Thanks
Sounds like you have a cylinder coming apart or maybe a line pinched. and maybe you are acierating your fluid due to a bad pump or suction leak
The hydraulic tank keeps getting pressurised somehow. I used to be able to undo the fill cap and let a lot of air out then the blade would work good again for half hr but now when i try that the oil comes out the cap instead of air. It almost is like the system is hydraulic locking with pressure but not real sure. The blade lever linkages work their way back and enter the front side of hydraulic tank. Theres a little bit of weep there where the pivot link is on front of tank. I havnt looked at the pump itself for a suction leak but I suppose i should havea look there and see. The machine has been used by someone else for a year at a different farm and the farmer bought a komatsu d65ex 17 for me to use where i work (which is nicer to operate) I was asked to clear a few km of old fence lines to build new fences at the other farm where this old d6 is so its been a year since i operated it last. But the hydraulic oil tank smells like hydraulic oil. I thought i used to just put engine oil in there but cant remember now. I think someones been using hydraulic oil to top it off. Would hydraulic oil be more likely to foam up over motor oil if the pumps getting bad? Thanks