Hydraulics too slow when cold

[bodean-HT]

I know this is a Yanmar site, but..........
On my JD850 (Yanmar 3T80J engine) that I bought last summer, the hydraulics are very slow, and sometimes will not work at all on colder days (below 55F). It takes warming it up for 20 min or longer before I see any improvement. When it does start to move, it's a little jerky. I changed the fluid, filter, and cleaned the wire screen. This seemed to help some, but still not up to par. I have also noticed a light rattling sound at the front of the engine at higher rpm's, but not sure this is from the pump. The pump is not serviceable according to the manual. Got any thoughts on whether it's the pump, or maybe another problem?

 

[alan-HT]

Is the fluid the right kind?

 

[bodean-HT]

I used the universal type. It's the Travelers premium multi grade (10-W-20) sold at Tractor Supply Co.

Stan

 

[alan-HT]

No idea what Deeres take, but if that's straight hydraulic oil, it would not work in a Yanmar, which requires hydraulic/transmission fluid.

 

[bodean-HT]

The manual just says to use only JD Hy-Gard transmission and hydraulic fluid (or equivalent). A friend who is a tractor mechanic says that the universal type is designed to work in majority of all tractors. Since the JD850 was built by Yanmar, I figured it would take the same fluids as Yanmar badged tractors. I'm thinking there was a Yanmar clone to it.....maybe the 2500?

Here's what I used; <LINK_TEXT text="http://www.externa...ns-hydraulic-fluid-5-gal--0806391</LINK_TEXT>


Stan

 

[Norm-HT]

If the pickup screen was badly plugged you may need to check/clean it again. Sounds like you still have an obstruction somewhere. If not there, or the filter, could be anywhere.

 

[bodean-HT]

The screen was plugged fairly badly. There were lots of large bits and particles on the outside of it that required scrubbing with a brush in my parts washer. I have power steering and the hoses are frayed on the outside. I'm wondering if maybe they are doing the same on the inside, also.

Note; The hydraulics have always been a little slower than the Yanmar YM1700 that I replaced it with, even during the warmer months. On the JD forum, it was suggested that I clean the screen and replace fluid and filter. They are very slow to respond on that site, so I decided to bug you folks instead for some quick ideas for me to try while I'm on vacation.

 

[Norm-HT]

Large bits and particles of WHAT on the screen? I can't find any info that says anything but your engine was built by Yanmar; however Yanmar says HY/TRAN fluid = or better than JD303, which is probably what you have.

 

[alan-HT]

That would seem to be your answer. Something has been or is shedding internally, and it's unlikely to be the hoses. Does the debris look like it was once an O-ring?

 

[Aaron-HT]

Also check the rubber coupling in the suction line (assuming deere has those too). The couplings get cracks or get loose &amp; allow air to get sucked into the oil. This causes foaming and slow movement. This is found more often in cold weather because the oil gets thicker causing more suction to pull the air in &amp; the hoses get stiffer and crack/get loose.

just another idea...

 

[bodean-HT]

The particles on the screen did not look metallic.....well, anymore than the fine stuff an automatic transmission would have from normal wear. The larger particles did seem to be hard rubber and could have been an O-ring. There about 15-20 particles about the size of BB's, but the rest was mostly a sludge build-up. Not a milky white sludge, mind you, but a thicker than the fluid type sludge.

There are no visible leaks anywhere other a slight wet look around the shifter boot. Looked the same way on my Yanmar, though. I think Aaron may be on to something with the air/foaming idea. About the same time the lift started getting slower, I noticed a sort of whine noise that was more evident with higher RPM's and colder temps. I did not think to check the dipstick for foaming, but will do that once the weather dries up around here. The whine sounds like a power steering pump that has run dry, but it only occurs at higher RPM's (say, above 1600). I'm gonna have to look back through the manual to see if there is a rubber coupling.

I really appreciate every ones ideas on this. It's the main reason that I keep coming back to this site.

 

[bodean-HT]

I still have not figured out the problem. There is no foaming, the fluid I used says equivalent to JD303, and I have yet to locate any rubber suction line grommets. About where would this grommet be located? The only rubber parts that I have are the hoses connecting the larger hard line coming from the pump to the filter, then from filter to screen housing. Then there are a couple of crimped-on hoses under the seat.

I attempted to take a pressure reading, but not sure the port that I used was correct. The one that I hooked the gauge to was stamped T on the diverter block for the power steering. The one pictured in the manual looks totally different from mine, so I can't really go by that for a reference.

A local shop allowed me to hook up a new pump, and the lift did work immediately upon start up (although jerky), but when I lowered the implement down, it would not lift it again. How likely would it be that the pump drive gear is not turning the pump? Looks like it is camshaft driven. Is there a key on the drive gear that might be sheered?

 

[Norm-HT]

How was the pick-up screen when you re-checked it? Nothing but hands-on troubleshooting is going to find your problem. The control valve under your seat is loaded with "O" rings.

 

[Aaron-HT]

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Those are the couplers I was talking about.

Are you sure you have the right filter on it? There are a lot of filters going around that are WAY too fine &amp; restrict the flow to the pump.

 

[bodean-HT]

The screen was completely clean when re-checked.

The hoses/couplers that was mentioned look to be in good condition and the clamps are tight. I'll pull them off anyway and check for any internal separations that may cause blockage.

The filter is a Fram Extra Guard # PH8A which was what the local Tractor Supply Co. manual said was the equivalent to the JD filter.

The local dealer that let me buy/try a new pump has said that they would allow me to return the pump if I let them do the other repairs. If I have not gotten this fixed by this afternoon, it's going to the shop.

Stan