I forgot to put a link to Hoss54's original thread so here it is. http://www.skidsteerforum.com/DesktopDefault.aspx?tabid=54&frmView=ShowPost&PostID=2329
I really can't see how air could enter the system if the oil level is correct and there are no leaks. Did it just start having this problem? or has it been doing it for a long time?
I have noticed purging the air from my 743 has taken quite a long time and its still not rite. I had the lift arms working well, but when i attached the tilt cylinder i now have air back in my lift arms. Could it simply be air traped in the system that will eventually bleed out?
Can you give me a bit more info on the history of the problem?
The hydraulic circuitry is a closed loop with the reserve above the pump, there is no way i can see for air to be drawn in. No hoses run at a negative pressure to draw air in, they are all at charge pressure or higher (except the hose to the reserve tank that just has gravety against it).
There has to be an answer, as there are 2 people on this forum alone that have this problem, surly there will be more around.
One thought, the only other thing i could think of is bad ram seals. All the rams are double acting, this means you need constant pressure against the pressure seal for it to seal against the rod. If you have a load on the ram and move the spool when the engine is off, i guess there is a chance it could draw in air (still very low i would guess) as the rod retracts causing a low pressure at the seal and sucking in air?? Its just a thought.