M5040/M6040/M7040 clunking/gurgling hydraulic steering pipes – any definitive answer?

knightbaker

New member

Equipment
M5040DT, M20 FEL, Allis Chalmers 170, BCS 725
Aug 28, 2016
7
0
0
Hazelton, BC
Hi all, I have a recently purchased 2009 M5040 (300 hrs) that makes nagging erratic clunking/thumping/banging/gurgling noises in the hydraulic steering circuit most noticeable at idle. Holding the metal pipes, you feel pulsations in time with the noise, from the pump right through the steering controller to the oil cooler. I suspected air from a suction leak, somehow...

However, perusing old threads in this forum and others, it sounds like there are many similar complaints with non-cab M series from these years since day one (the first models with the hyd pump on the transmission I believe). Lots of tales of repeated service trips to dealers, replaced relief valves, pumps, seals, bypass valves, steering controllers, all to no avail.

Does anyone have anything definitive on this problem? Either a fix or a letter/service bulletin from Kubota saying not to worry about it? Or have you been running a machine making these noises for 5000 hours with no ill effects?

I tried contacting Kubota Canada and my local dealer, neither of whom admit to any 'known problem' (and it's a 1000km round trip to take the machine to be looked at). The hydraulics and the rest of the machine function great, I would just like to put my mind to rest on this nagging noise. Many thanks!
 
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North Idaho Wolfman

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L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
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Sandpoint, ID
If you think it's sucking air, check the suction line, common issue is a cranked or split rubber hose.
 

Tx Jim

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M7040 HDC-1,JD 4255,Ford 6700
Apr 30, 2013
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Coyote Flats,Texas
My '11 M7040 HDC-1 that I bought used 2012 with 137 hrs on speed-hour meter made hyd clunking noises. Either the clunking(gurgling) noises have dissipated or I've adapted my senses as I don't notice these clunking noises now. Speed-hour meter shows 1375.3 hrs.
 

knightbaker

New member

Equipment
M5040DT, M20 FEL, Allis Chalmers 170, BCS 725
Aug 28, 2016
7
0
0
Hazelton, BC
If you think it's sucking air, check the suction line, common issue is a cranked or split rubber hose.
Thanks. The suction line on these machines is only a 4" long metal elbow from the dual filters in the tranny housing to the pump with O rings on both ends. It sounds like these were the first years the pump was mounted on the transmission, and according to speculation in other threads an engineering flaw causing some kind of cavitation or irregular flow with no apparent fix (and supposidly only on the non-cab models)

It sure does sound like air to me, but precious view places air could get in. Oil level is good, filters clean and tight (same issue before and after changing fluid and filters), O rings on suction tube fine. I'm hesitant to rip the pump apart to change the seals when is sounds like that has been tried by others to no avail. If the shaft seal on the pump is leaky, would it suck air or blow fluid?
 

North Idaho Wolfman

Moderator
Staff member
Lifetime Member

Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
Jun 9, 2013
28,560
5,026
113
Sandpoint, ID
If the shaft seal on the pump is leaky, would it suck air or blow fluid?
Normally if the shaft seal is leaking it would blow fluid, But let me do a little more research on the pump.
What exact model do you have?

 

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knightbaker

New member

Equipment
M5040DT, M20 FEL, Allis Chalmers 170, BCS 725
Aug 28, 2016
7
0
0
Hazelton, BC

M7040Josh

New member

Equipment
M7040
Wish I would have came across this forum earlier. Has anyone found a fix. I’ve noticed this hydraulic gurgling noise on my M7040 and have been trying to pinpoint it. I can feel it pulse in the cooler lines and back at the line on the pump. Also looking through the rear fill cap the fluid does bubble a bit. First thing that came to mind was to check the suction side, so I pulled my pump and checked suction O-rings. All o-rings were good. I had the pump out and decided to check it next. All seals looked good and so did the pump besides normal wear. Waiting on a seal kit and putting it back together.
 

knightbaker

New member

Equipment
M5040DT, M20 FEL, Allis Chalmers 170, BCS 725
Aug 28, 2016
7
0
0
Hazelton, BC
Wish I would have came across this forum earlier. Has anyone found a fix. I***8217;ve noticed this hydraulic gurgling noise on my M7040 and have been trying to pinpoint it. I can feel it pulse in the cooler lines and back at the line on the pump. Also looking through the rear fill cap the fluid does bubble a bit. First thing that came to mind was to check the suction side, so I pulled my pump and checked suction O-rings. All o-rings were good. I had the pump out and decided to check it next. All seals looked good and so did the pump besides normal wear. Waiting on a seal kit and putting it back together.
2 years on now on my 2009 machine, and still the same issue exactly as you describe. My theory is an engineering flaw that froths up the fluid (from the return lines?) and those bubbles make a racket in the narrower gauge cooler/power steering pipes (cavitation?) but are not noticeable in the main hydraulics. My chosen solution is to always wear my hearing protection around the tractor, and the noise doesn't bother me at all!
 
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M7040Josh

New member

Equipment
M7040
Just an update since I resealed the hydraulic pump. I saved the hydraulic fluid since it I just recently serviced it, but changed both filters. The tractor does not make the gurgling noise from the hydraulic system like it did before.
 

knightbaker

New member

Equipment
M5040DT, M20 FEL, Allis Chalmers 170, BCS 725
Aug 28, 2016
7
0
0
Hazelton, BC
Just an update since I resealed the hydraulic pump. I saved the hydraulic fluid since it I just recently serviced it, but changed both filters. The tractor does not make the gurgling noise from the hydraulic system like it did before.
Thanks for the update Josh, guess I'll order a seal kit myself. Is it a fairly straightforward job? I had made the assumption that a leaky pump seal would likely blow fluid, rather than suck air...