New Hydraulic pump chattering

[jtaylor-HT]

So I have had my YM1900 for about 2 years and have since: rebuilt engine with new sleeves, pistons, bearings, valves and painted tractor along with other modern features. Hoye Tractor had all of the parts and I could not be happier.

However, I noticed last summer the tractor had a hard time picking up my bush hog and picked it up slowly. Also I could lift a light attachement all the way up, then lower it half way and try to raise up again and it would not. I could then lower it and then pick it up slowly. Well orings do go bad after 35+ years. So I conducted the leak down test as outlined on Hoyetractors website. So I ordered the parts to replace the piston oring and all other orings that are part of the lift. Everything went well and looked good. Everything was cleaned and checked out okay.

So after I got everything back together I was excited to try to push some of the 40.5 inches of snow we got 2 weeks ago and have fun using my yanmar. The tractor now even struggles to pick up the blade to full height. So it has to be the pump as well. I know the pumps are expensive, but I wanted a quality pump that would last and lift. I did not even look at the junk out there and bought the one from Hoye.

During removal of the old pump I did not notice anything out of the normal. While waiting on my new pump, I drained the hydraulic fluid, cleaned the screen filter (only 20 hrs on it). I pump everything back together and waited for the pump. The pump have ARRIVED. I installed the new pump taking special care to keep it clean. Before starting the tractor I opened the hydraulic fill port as to avoid the possible of a vacuum and starve the pump of oiil for those first very seconds. Tractor starts and I hear a little chatter coming from the pump. I worked the lift with no load a few time to purge air. The pump still chatters especially when the lift is all the way down. I can move the lift just as it starts to move and the chatter stops. The pump does not chatter while lifting but will during lifting. I did not want to run it anymore, so I called Hoye to advise me. The fellow said that it can be expected get some chatter, because the pumps are tight and let the new parts wear in a little. Hoye has great people but just like to see if others has experienced this. Would it be advisable to remove pump and turn the shaft/coupler 180 degrees,run it a little at slow speed and take back apart and inspect, or.........or is this an expecte noise until break in of new pump.....

BTW those pumps from hoye are FAST and Responsive!



Thanks in advance for your input

 

[Norm-HT]

I suspect you have a blockage someplace else. Have you checked the hydraulic valve or the servicing stop valve?

 

[jtaylor-HT]

Aaron. I had the taken off the all the valves for the 3 point lift and cleaned everything when I installed new prongs in the lift cylinder. All oring was present when I took apart. The lift is working great with the new pump. It just seems like the coupler is chattering when the lift is all the way down or while being let down. Maybe I should replace the pump coupler.....it did not have much wear at all when I took the old pump off

 

[Aaron-HT]

Do you have a loader on the tractor?


Sounds are extremely hard to diagnose remotely like this so we are at a bit of a disadvantage here. The new pumps will normally make more noise than the old pump until they get broken in. That is normal and is just due to the tightness of the gear mesh on the new pump. The noise is more of a slight whine or 'whiiiirrr'... again... hard to describe using letters <E></E>

A pump that is any louder than that might be in trouble. A restriction in the system will make a squealing sound in the pump. That is the sound of oil that has nowhere to go getting pushed through the pump's internal clearances. The pump WILL pump oil when the engine running and if that oil has no where to go or if enough of the oil is blocked that the pressure builds- something has to give. An older pump can let a little of that pressure slip through the gears and not cause much trouble. A new pump is tight and those internal gears seal really well so they can not tolerate much restriction before something breaks. The pump housing, shaft, or shaft key are common failure points.

 

[Norm-HT]

Aside from a plugged pickup screen these obstructions are normally bad "O" rings that have broken loose. Be sure to check all, using the parts manual.

 

[Aaron-HT]

That is right. The sound could be a pump that is cavitating or just not getting enough oil - caused by a clogged screen or a loose/cracked rubber suction hose letting in air.

 

[Norm-HT]

The broken "O" rings can not only let in air but the pieces can literally block the hydraulic lines and cause squealing and chattering.

 

[jtaylor-HT]

I dont suspect an blockages. I replaced all of the oring in the valves under the seat and replaced the oring on the piston. Also I do NOT have a FEL. Also as i mentioned I cleaned the filter screen (which only has about 20 hrs on it) when I change the hydraulic fuild when I replaced the pump. I also replaced the 2 oring at the pump. Averything works just fine, but the chattering when I have the lift control lever all the way down or when letting it down. I can let the lift all the way down then lift it a little and the chatter does away. Also it does not chatter while lifting. It is more noticable as the engine speed is raised. Have a look for your self from the video I just took

<LINK_TEXT text="https://youtu.be/7...L5-eK92FrA_TsoxzwIC6alX5_8NvoG4w9</LINK_TEXT>

 

[Norm-HT]

Report again after 20-30 hours use. I also hear a little tap tap tap from somewhere. What could that be <E>:wink:</E> ?

 

[jtaylor-HT]

Norm. I think you was hearing the chatter from the pump while the engine was at idle. The engine is fully rebuilt including sleeves, pistons, rings, bearings and the head is rebuilt with new parts (20 hours on rebuilt engine) . It just seems weird to me. The noise goes away if I slightly raise the control lever. No noise during lifting. I get the chatter while lowering it. It just seems if the pump has no load or the control lever is down is the only time I am getting the chatter. I just hope this is just a noise during break in noise. Aaron mention and others mentioned the tightness, which could explain the noise. It almost seels like a sound that would come from a friction clutch plate if it did not have those springs dampening the movement. The pump mates up to the gear inside, which has a little tolerance to allow you to blindly fit it on the gear. With the tightness of the new pump may be causing the noise and settle down after a few hours of work. I just checked everything and rechecked because of the warnings of blockage. I just know I do not have any because I had it all apart, cleaned everything, changed hydraulic oil. Hopefully other will look at the video and provide possible things to check. I just hesitate to run it with this noise. Thanks for you help!

Jake

 

[winston-HT]

I can't see the bucket so just checking, correct fluid? I don't here anything that sounds to be in a bind. What does it sound like when picking up a load?

 

[jtaylor-HT]

Winston. The hydraulics is plain jane with no add ons. Supply line from sump to pump and high pressure line to lift. When I changed the pump I changed the hydraulic fluid with Renew by traveler (meets spec JOHN DEERE 303 FLUID (JDM-J20A, JDM J14B)). The noise is not present while lifting with no load. I do plan on trying it with a load this evening to see how it does.

No load on lift.
1.control lever all the way down = chatter
2.move control lever up = makes no noise while lifting and does NOT chatter while while the lift is full up and not moving.
3.lower the the control lever down from the all the way up position = chatter
4. with lift all the way down, then move the control lever up until the lift is getting ready to move = chatter goes away

It seems as soon as a little pressure is pump on the pump the chatter stops. But is the pump is in a freewheel position, then I get the chatter.

On another note, as someone mentioned in this thread about getting air at the rubber joint on the fuild intake line. I did NOT replace that peice when I changed the fluid, pump and cleaned the screeen and replaced all orings. But if I had an air problem I would thing I would get cavatation on lifting and not a noise while at rest or lowering the lift.....

jake