manant 57 #1 Posted May 8, 2017 I have a '73 C160 automatic . The mower hydraulic lift works fine when I first get started, but after mowing for a while it loses lifting power. I do not notice any change in forward speed, but the reverse speed does not seem to be as fast as when I start out. Would changing to 10w40 oil in the transmission help? I have 10w30 in it now. Anything else I can do. Share this post Link to post Share on other sites
Thisguyisnew 114 #2 Posted May 8, 2017 Make sure you have enough oil in system. Share this post Link to post Share on other sites
pfrederi 18,711 #3 Posted May 8, 2017 Has the filter been changed recently, what type filter was used? Any sign of leakage at the cylinder? Does it hold the deck up in the air after it is shut off? (For how long) 10w-40 wouldn't hurt but may not resolve you issue. The lift runs off the charge pump. If you have access to a pressure gauge (1000psi ) run a pressure test cold then hot. Share this post Link to post Share on other sites
manant 57 #4 Posted May 8, 2017 Thanks for the info. The oil reservoir is full (maybe little too much in fact). I recently changed the oil and filter to see if that would help. The filter is a Purelator similar to Nappa 1410. That is what was on it when I got it and through several oil changes. The oil on the dipstick is clean and clear. I usually lower the mower when I have finished so do not know if it holds in the up position when not in service. Sometimes I see oil on the left footrest near the cylinder, but have not seen any recently. I think a hose was slightly loose on the lift control which I tightened. Agsin, thanks for your help. Share this post Link to post Share on other sites
pfrederi 18,711 #5 Posted May 8, 2017 Try leaving the deck up and see how long it stays. If there is an internal flaw in the cylinder it may get worse as the oil thins out. Failure to operate in one direction diagnostically lead to charge relief valve and/or acceleration valves. Acceleration valves would not influence the lift cylinder but the charge relief valve could. I note yours still works in reverse but get weaker slight leakage gets worse with heat???? Share this post Link to post Share on other sites