ohioC160 1 #1 Posted December 27, 2017 I have a 1977 C-160 hydro, hydraulics work sporadically, never know when they will work or not. Changed out trans oil and new filter, I have manuals on Sundstrand transmission, but there is no troubleshooting concerning hydraulic lift. Can anyone help? Share this post Link to post Share on other sites
pfrederi 17,893 #2 Posted December 27, 2017 (edited) Assuming tractor drives normally (good power even when warmed up) i would suspect the implement relief valve. The spring may be broken or the ball not seating well.that would preclude generating enough pressure to operate the lift. (See page 5 and 35 in the manual) Do you have access to apressure gauge that will go up to 1000 psi to run a pressure test??? Welcome to Red Square!!! Edited December 27, 2017 by pfrederi 1 1 Share this post Link to post Share on other sites
ohioC160 1 #3 Posted December 27, 2017 Thank you! I'll consult the manuals again. Mine are repro's - best I could find on net. I do have a gauge and will try a test. Based on your comment, I'd say, assuming the pump is building proper pressure, the relief valve must be sticking open. Do you have a reliable source for parts? Dealers around here are hit and miss on parts. 1 Share this post Link to post Share on other sites
pfrederi 17,893 #4 Posted December 27, 2017 Try downloading this copy Check with A to Z tractor in our vendors section here. For new parts try LJ Fluid Power 1 1 Share this post Link to post Share on other sites
953 nut 55,860 #5 Posted December 27, 2017 1 hour ago, ohioC160 said: pump is building proper pressure, the relief valve must be sticking open. I would agree that if it drives well the relief valve spring is the most likely suspect. These manuals are another set for Sundstrand. In addition to A-Z and LJ Fluid you may be able to find some parts by contacting member @daveoman1966, he works with them. Sunstrand Hydro (part 1).pdf Sunstrand Hydro (part 2).pdf Sunstrand Hydro (part 3).pdf Sunstrand Hydro (part 4).pdf 1 Share this post Link to post Share on other sites
KC9KAS 4,741 #7 Posted December 27, 2017 @ohioC160 to Share this post Link to post Share on other sites
