bslms 19 #1 Posted September 23, 2016 Hi All, I recently took possession of a 75 C120 with the Sunstrand hydro. I am curious as to the performance and durability of that hydro. The Tow Valve is frozen and will not release. As a result, I am sure that it has been thru a fair amount of dragging around with the hydro engaged. I have not had time to actually fire it up and see how (if) it drives. I am unfamiliar with Sunstrand motors and have to start doing some research for service and parts availability. Anyone have any info on where to start? Any info will be appreciated...Thanks. 1 Share this post Link to post Share on other sites
953 nut 60,220 #2 Posted September 23, 2016 Begin with a quick check of the oil to see if it is at the proper level and looks and smells like oil. A few shots of PB Blaster or your favorite penetrating oil should free up the tow valve. My 46 year old Sunstrand works great. 2 Share this post Link to post Share on other sites
elliot ness 1,916 #3 Posted September 23, 2016 Yes PB blast something like it will help, and the Sunstrand is very strong and I have never seen a bad one. 1 Share this post Link to post Share on other sites
daveoman1966 3,841 #4 Posted September 23, 2016 The 75 C-120 has the Sundstrand power unit and here is a schematic of it for future use. Your tow valve is item 46 in the pump schematic. Once up and running, I'd urge you to change the oil (or ATF) and filter. Do this CAREFULLY and in a clean area. Do you have the hydraulic lift with it? If not, I can get you there. Its the same as on my C-160 and I'd not be without it. MOTOR 90-1136, 37, 40.xlsx PUMP 90-1136, 37, 40.xlsx 2 Share this post Link to post Share on other sites