Buying Advice Need some advice on hydraulics

[jcimob]

YM155 D with loader and 3pt snow blade. Doing a lot of snow clearing and have begun to notice hydraulics, particularly on the loader are slower, and now just lately a little jerky in movement. For example curling the bucket, it moves slow and sometimes jerky.

I know I have some small leaks (some hydraulic fluid drips on garage floor) but nothing major. I checked the fluid level and it seems fine (I am checking the right place aren't I......small dip stick under the tractor seat).

No troubles until now. I am thinking now to remove and clean the filter but would like some input before I go that route. Should I change all the fluid also?

thanks
Frank

 

[tony123]

I'm anxious to hear what feedback you get, as I notice the same thing on my tractor. Particularly, the cold weather seems to effect fluid flow, and in turn, operation speed. I'm hoping to hear that it is common and to be expected.

 

[JerryG]

Most compact tractors will have a suction screen in the transmission. This screen will get plugged up and slow the hydraulics or sometimes stop it all together. Even if the fluid has been changed, sometimes the screen isn't cleaned. I would check to see if your tractor has this screen and if it does, take it out and clean it.
The fluid isn't white colored is it?

 

[RonMar]

Jerking operation usually indicates air in the lines. If your resovoir is all the way at the back and the pump is all the way up at the front, check any fitting on the suction line between pump and resovoir and make sure the strainer is clean. Hydraulic pumps were designed to make pressure, they are not so good drawing in fluid under a vacume and the situation gets worse when the fluid gets cold. On the suction line, it is far easier to draw in air thru a pinhole leak than to draw cold fluid thru a strainer. A small leak on a suction line may not drip because of the low static pressure, but will probably show signs of oil and dust accumulation in the wet spot. Your description of the symptoms getting worse sounds like a fitting that has started to work loose and is admitting more and more air into the suction line. IF all the suction fittings are dry, clean and tight and the strainer is clean, another possibility is a seal in the pump body sucking in air due to the high vacume trying to draw in cold fluid from the resovoir.

What fluid are you using. I am not a fan of mixed systems that use one fluid(UTF) for gear and hydraulic systems. It is a compromise, a little thin for gear oil and a little thick for hydraulic fluid IMO and I think you will start to see problems in one extreme of temp or the other.

IF all the fittings are tight, can you get it into a garage to warm it up really well? IF so do that, point a space heater at the case and get the temp up into the 60's or so, then take it out and work it with a good warm system and see if the problems persist. If it is fine when warm, your fluid is most likley too thick at the lower temperature or you have an internal pump problem.

Good Luck

 

[Kernopelli]

Just experienced slow hydraulics on my loader during cold weather. Turned out to be the suction screen. It really didn't look all that dirty but a good cleaning and everything was back to normal.

 

[lens12]

Jerking is usually a sign of a plugged filter. Since it is cold , it is probably moisture in the screen. As to the comments about one oil for hydraulics & transmission. this is a common practice on most farm tractors since at least the early 60"s. The correct oil is a hydraulic/transmission fluid. It is formulated for wet brakes & clutches, gears, bearing, & hydraulices. I have one tractor with over 9000 hours with the original hydraulic pump. It has neery had a gear or bearing problem in the transmission..

 

[jcimob]

thanks for the feedback.
I just drained the hydraulic oil, then took off the filter. It did not seem extremely dirty to me, but no experience in that. I cleaned it in some solvent. I do see some very fine metallic flakes. Not sure if this is a bad sign or normal wear and tear. This is the first time I have done this on my second hand tractor so no idea of how many hours since the last filter clean. Maybe someone can comment.
I don't see a gasket, but I do see some silicon around the flange which I am sure was used as the gasket. I guess I will replace with the same, or use some liquid gasket material.

I hope this fixes my jerky and slow hydraulics on the loader. If there is air in the lines, any ideas on how to bleed it out?

thanks
Frank

 

[RonMar]

Any air in the lines should work itself out, as long as it is not being replaced by new air

 

[green yanmar]

i have a ym 135 basicly the same as 155 just smaller anyone have a pic as to where the screen is?need to clean or replace after the loader project is finished also changing the fluid

 

[jcimob]

Green Yanmar
I found mine here.............look below the low range or 4wd shift lever on right hand side (where your gas petal foot rests). You will see a metal pipe ending in a flange, that is held on by 3 bolts to the transmission case. On the opposite side of the transmission case from this flange is the yellow plastic drain plug. Drain the transmission, take off the 3 bolts and pull the flange and metal pipe back and the filter shows up on the other side. It is slipped over the metal pipe on the inside, kind of held in place with a rubber oring inside the filter.
Mine was not all that dirty and after putting it all back together and refilling, I notice that I now have a small leak at that flange. Guess my liquid gasket was thin in one place or something. I got a tip from a local farm boy who works on tractors, he says that I should not have tightened the flange right down hard, since this squeezes all the gasket goo out. He suggested the best way is tightening down until almost tight, then waiting awhile and then retighten slightly, but not down really hard (which is what I did). I guess I will try that when I repeat the exercise.

hope you have success the first time
Frank