1755 hydraulics

hey everyone i have recently purchased my second tractor in my collection. it's a 1755 FWA with a 1855 turbocharged waukesha. we have been testing it and working out the kinks and have recently noticed the hydraulics seem to act sluggish. for example i was raking hay with it and within the first hour the hydraulics would pick up and drop the rake wheels just fine but after that it would get slower and if i had the brakes in it would practically crawl. is it a pump problem, leak somewhere, or am i simply not have enough hydraulic oil in it? my dad and i are not use to these closed hydraulic systems. any help is appreciated.

You did not check the oil before you started the day? What oil are you using? Do you have a shop manual? How about a 3000 PSI gauge? You need to check the components out by the book not guess at this.

By the way post the serial number as well as there changes in the 55 series hydraulics.

the serial number is 260-336

Jordan:    Talk about a late 1755, there was only 9 of the 1755 through 1955 series tractors built after yours.   Your tractor has the late gerotor cooler pump, last 15 series Vickers pump and Char Lynn steering control.

   A quick review, the system is a closed center system, meaning that all the valves are closed when in "N".   All systems should be blocking fluid flow.   You can't completely close off flow in the valves that have moving components, you have to have some clearance.

   Simplest test on a tractor with the closed center system: With the system fluid temp at ambient.   Start the tractor and let it run at medium RPM, Don't steer it or use the brakes, go away and let it run for 15 minutes.   After 15 minutes, feel the lines all over the tractor, you are looking for a line that has hot oil flowing through it, remember everything should be blocked.

   I'm pretty sure you will find the pump case drain line coming off the end cap of the pump to be the hot one.  [b:654c4848f0] Pump test:[/b:654c4848f0] warm the fluid temp to 110 degrees ( you can just hold your hand on a line that has 110 degree fluid flowing) perhaps you can borrow a cooking thermometer.   Turn the fitting on the pump end cap up and put a hose on the fitting to make a loop higher than the fluid level in the reservoir. Start engine and run at medium RPM,you should get no more case drain than one quart flow in 15 seconds.   Be careful when you make the drain test, as a bad pump will really flow fluid and hot fluid can splash out on you.   You said it works OK when you start to use it, then slow down.   As the fluid warms it's resistance to flow is reduced, thus fluid is slipping by the internals of the pump into pump case.   More than above flow means the pump has too much internal wear and needs to be rebuilt or replaced.

You were given some very good advice, but do invest in a gauge so if adjustments are necessary you can do it correctly instead of guessing at where you are at. I used to have small magnetic thermometer that I could stick to components and check their temperatures that worked well too. We have a customer that has 3 2-85 tractors and we have had to make adjustments to all the hydraulic systems and none had the same adjustment problems. J.