Jon925mn 39 #1 Posted November 28, 2021 C-145 with sundstrand transmission. Confused about hydraulic lift with front snowblower. Sometimes it works pefect and another day it won't lift the blower. Couple months ago replaced all hoses due to rotted seals and rebuilt the control valve. When it works it raises the blower and holds it fine but then on a different day the cylinder rod will move and stop just as the blower starts to raise. Jekyll and Hyde has to have an explanation. Share this post Link to post Share on other sites
Achto 27,512 #2 Posted November 28, 2021 Is your fluid low by chance? These pumps also work better once they warm up. 1 Share this post Link to post Share on other sites
Jon925mn 39 #3 Posted November 28, 2021 Level good and new (10-30) with WH hydro filter. Tractor running 15 min. and no difference. Yesterday it was 30 degrees and lifted fine from start Today 35 and it wont lift. Share this post Link to post Share on other sites
Ed Kennell 38,032 #4 Posted November 28, 2021 Does the tractor move OK when the lift doesn't work? Sticking valve or broken spring? Share this post Link to post Share on other sites
Handy Don 12,170 #5 Posted November 28, 2021 There is a pressure relief valve in the Sunstrand that lets the fluid bypass the lift circuit (intentional to protect the pump when a cylinder reaches end of travel while the control valve is still in "raise" or "lower" position). I'd bet that its seal or spring is damaged or something is stuck in it. Share this post Link to post Share on other sites
Jon925mn 39 #6 Posted November 28, 2021 Tractor does drive forward and reverse. It is somewhat touchy or bit jerky when pushing lever but not terrible. Reverse seems a little slow but not bad. I have 200lbs weight on back bracket and she goes up a hill. Where is this pressure relief valve in the Sunstrand ? Servicable? Share this post Link to post Share on other sites
pfrederi 17,681 #7 Posted November 28, 2021 32 minutes ago, Jon925mn said: Tractor does drive forward and reverse. It is somewhat touchy or bit jerky when pushing lever but not terrible. Reverse seems a little slow but not bad. I have 200lbs weight on back bracket and she goes up a hill. Where is this pressure relief valve in the Sunstrand ? Servicable? Yes...it is serviceable. You need to look at the sunstrand manual You have a piston to piston so the relief valve setups are specific to them (not the older hydrogears) 1 1 Share this post Link to post Share on other sites
Handy Don 12,170 #8 Posted November 29, 2021 (edited) 3 hours ago, Jon925mn said: Tractor does drive forward and reverse. It is somewhat touchy or bit jerky when pushing lever but not terrible. Reverse seems a little slow but not bad. I have 200lbs weight on back bracket and she goes up a hill. Where is this pressure relief valve in the Sunstrand ? Servicable? Thanks for digging this out @pfrederi and posting it -- you saved me from going hunting! I read about the valve while doing some other research but I've never worked on a Sunstrand so I had no idea where it was or how to service it. (It was a nice feature of Sunstrands, one that the Eaton 1100s don't have--they require an external implement pressure relief valve.) Edited November 29, 2021 by Handy Don Share this post Link to post Share on other sites
Jon925mn 39 #9 Posted November 29, 2021 Can't seem to open file after download so can someone send a picture of which bolt is the service valve. Thanks Share this post Link to post Share on other sites
Jon925mn 39 #10 Posted November 29, 2021 Also took off 2 cylinder hoses and can only move rod forward about an inch. It puked some oil then just clunks and stops. Seems without hoses on the rod should push. Share this post Link to post Share on other sites
pfrederi 17,681 #11 Posted November 29, 2021 Cylinder should work all the way in and out with hoses off.... Try downloading this version. You really need it when you tear into these things.. Implement pressure test may be enlightening also Share this post Link to post Share on other sites
