240D hydraulic problem

[Pyrodude]

Hi all! New to the forum and new to tractors. I recently bought a 240D (with only 246 hours, the seller said. Yeah, right!) Got it home and changed the engine oil and did some mowing on 2 weekends and everything worked fine. Last week I moved some dirt around with the FEL and everything worked OK. A couple days ago I drained the hydraulic/trans fluid and cleaned the strainer which was covered with a moderate amount of gunk. I refilled with JD 303 compatible oil from Wally World and now, neither the FEL or 3pt hydraulics work. I cracked the hydraulic lines where they go into the maniford under the seat and also at the top of the 3pt pitch and all I got was a small dribble of oil - nothing under high pressure. I also noticed that when the tractor was at idle and I tried to move the hydraulics, as the valve was opened there was no "load" or bogging of the engine as there was previously. I just talked to Hoye about it and they suggested air in the lines or a sheared key on the pump shaft. Any other ideas? Everything was working fine till I applied some "preventative" maintenance!

 

[HoyeTractor]

Did you unhook the hydraulic lines to your loader at any point when you did your maintenance? My guess is the pump was deadheaded. Happens a lot. Remove your pump and I bet you find a sheared key or twisted pump shaft.

246 hours is not out of line for a YM240. He may have been telling the truth.


Oh... and welcome to TBN!!!!

 

[clemsonfor]

i bet it was more like 1246 hours though? I cant see only putting that much time on a tractor in 30 years!! in 4 i have put on 160 hours and except that first year mowing out of control fields i dont use my tractor much at all!!! its 3 hours from me. If i lived with it at my house on even a smaller property i would have twice that i bet, and that means in 30 years that number would be more like 800 hours. even if i parked it after 15-20 years it probably would have 400 and thats at my extreme low useage right now.

Anyway, i agree with aaron sounds like maybe a sheared pump? Just dropping the fluid and cleaning the strainer will not do this. they self bleed themselfes so that is not a concern. Something else happened here. did you close your under seat valve off?

 

[Pyrodude]

I didnt do anything to the tractor before draining the fluid and pulling the strainer. I used the tractor for about 3 hours on Saturday and parked it and on the following Weds went out and without moving it or doing anything else to the tractor pulled the plug and drained the fluid. I let it sit for a day without the plug and strainer before reinstalling them and refilling the transmission. Is it possible I blocked the suction line at the strainer by installing the strainer incorrectly? I did try moving the valve under the seat to different positions but that was only after everything was re-installed and things were not working as they had before. How hard is it to remove the pump? I havent really looked at that yet.

 

[winston1]

Not sure you could install in wrong. Yanmar Tractor Parts: HYDRAULIC_SYSTEM

 

[careyo63]

The Service Stop Valve is the Round/Flat Knob between your legs if your sitting in the seat. To prevent it from closing I open it all the way. And if I'm Serv. a Imp. I make sure it's closed all the way. No in between. The 2nd. pic. is the Drop rate and I'm wundering if that is the Adj. you were moving? I would have already pulled the pump and checked the Key Way. My bet that's it also!

 

[Pyrodude]

Well, I don't think the hydraulic pump is the problem. Got it off the tractor and onto the bench for a closer look. The pump internals look good - the gears mesh well and there is no slop in the shafts. The coupler is in good shape and it came off the pump shaft without any problems. The key and the keyway were intact with no signs of slipping or scoring. Any other suggestions or ideas? Carey - I only fiddled with the round knob at the front of the seat and did not touch the the little lever at the rear of the seat.

Also, any tips on removing/installing the pump? I had to remove the front cover plate on the pump so that there would be enough room to get the pump off the engine. It would be a lot easier to install the pump with it all together. However, with the cover plate on, the pump bumps the vertical frame piece holding the radiator and there appears to not be enough room to get the pump on or off unless the cover plate is off.

 

[careyo63]

I would take the pump and have it tested while it's out. Very unusual for it to go bad but It's possible. I'm thinking Loader Valve but that will be next when you rule out the Hyd.pump. When you Install it back remove the Battery the 2 bolts, Both sides just under the side cover. May have to remove you Radiator hose and that should give you all the room you'll need.

 

[Pyrodude]

Wasnt able to get the pump tested but re-installed it back on the tractor. Still doesnt work. While running, I can pick up the 3 pt mounts by hand and move them up and down. Fiddled with both the round nob at the front of the seat and the small lever at the top/rear of the seat. There is no hydraulic fluid under pressure in the lines. The tractor is parked on a slight incline with the nose higher than the rear. I wonder if the slight slope and an empty supply line that was drained when the fluid was changed along with a tired pump may be keeping the fluid from getting from the sump to the pump.

 

[careyo63]

You're saying no pressure to the 3pt. what so ever! The only thing I can say without being there looking at the tractor, And reading back the only thing more I can ask is, How much Hyd. fluid did you refill it with?