JD755 Crawler Hydrostats

[Dreese2005]

Hello guys, Thanks for allowing me into your group. I am new to yellow iron ownership and I have an issue. I recently purchased a JD755 Crawler Loader not 100% sure of the year.

Serial Number "755-- 279538T"

This loader ran great for about 5 hours then it gradually slowed until it would barely move at all. First it would barley move with a load, then it got to where it would not go up even a small grade with an empty bucket. I checked the fluid level and it seemed fine. maybe a gallon low. It was at the end of the day so I shut her off and quit for the day. The next morning I fired her up and she ran great for about 30 minutes then the same thing.

I am suspecting maybe hydrostat fluid and filters? but why does it only act this way when the fluid seems to warm up?


The fluid level is ok (1/2 way up the sight glass)

I am not sure when the last time the hydrostat fluids and filter were changed. So the questions I have are

1, Am I on the right track with Fluid / Filters?
2, Is there something else that could be the problem?
3, If it is fluid and filters, how to I get all of the fluid from the system? Do I have to drain the hydros from underneath? if so where? the manuals don't really have much info on this.
4, Should I change fluid and filters or just start with filters?
5 What is the best fluid to use? Is there something that works better than JD hydro fluid?
6, Why does it only act this way when the fluid seems to warm up?

Sorry for so many questions but I just shelled out quite a chunk for this machine and I really dont want to tear it up or do somthing to cause more trouble.

Thanks!

[Jim B]

Welcome.

I will start by saying I have no experience with the 755 hydrostatic drive. I have been around other hydrostatic systems and know proper and clean hydraulic fluid and filters are critical, so changing filters and cleaning any suction screens can't hurt. I would recommend you stay with the fluid John Deere specifies. Your operator's manual should have the info related to servicing the machine's systems, is that a manual you have?

You say the manuals don't say much. What/which manual(s) do you have? In the JD bookstore it looks like the 755 has one technical manual (TM1137), but there may be some component manuals. Those normally have good diagnostic sections in them. I recommend you run the diagnostic checks in the manual(s) as I think guessing will get expensive quick.

Someone, having hands-on experience with a 755 may be along with some info. Good luck.