L175 hydraulic check valve?

[mx5.7]

I have owned a 1976 Kubota L175 17hp for about ten years now that I use for plowing snow, mowing, and spreading rock. I have always had troubles with the hydraulics. If the machine sits for more than about two weeks the three point does not want to lift with out first disconnecting the implement and second manually grabbing the three point arms and pumping them up and down a few times. The problem is worse in the winter time and sometimes it doesn't matter what you do you can't get it to work until blowing heat at the tractor for a few hours. When it does take off and work it works fine, it is fast doesn't bleed down or anything. Here is what I have tried so far. Checked all lines for leaks. Replaced hydraulic screen on left side of tranny. Changed oil to a trans hydraulic. Even tried a synthetic trans hydraulic made for winter use. Checked spool valve for wear. Replaced seals in cylinder as advice from dealer. I am wondering if there is a check vavle in the system to keep the pump primed. It is almost as the pump will loose prime until you pump fluid back by moving the cylinder up and down. My other thought is the pump is getting weak, but I would think that it would act up all of the time if that was the case. Thanks for any response ahead of time.

 

[eserv]

There isn't any check valve to hold prime. The only thing that can be happening when you "pump" the lift arms is movement of the position feedback linkage. you may have to remove the linkage and valve and free them up.

 

[bky]

I had a problem with my l245dt after I did a system oil change and used hydrouic
oil as the replacement. Loader wouldn’t lift fast and three points wasn't working as it should have. So I did some research and found the l245dt uses 9ow gear oil for the tyranny and system.