Newbie hydraulic chatter L4740

C

Corby

New member

Equipment
07 L4740 GST
May 16, 2013
9
0
0
Pickens, SC
Good Evening Forum,

I have been searching for the last hour or so trying to find a quick answer to my problem, hoping one of you can give me quick diagnosis as I don't think my issue is major.

machine: 07 L4740 with a 854 laoder
330 hours
oil change by me about 50 hrs ago
no knowledge of hydraulic service

problem:
on start up and low rpm the loader chatters on the way up and the power steering is stiff or jams, in my limited knowledge of HYD I checked the fluid level and it was fine. I did notice it had what looked like bubbles in the fluid

at higher RPM the issue subside a bit but you can still tell that the system is not 100%

Loader has never been removed

Could this just be a dirty filter?

any help would be great, thanks in advance
 
Bulldog

Bulldog

Well-known member

Equipment
M 9000 DTC, L 3000 DT
Mar 30, 2010
5,440
78
48
Rocky Face, Georgia
Might also look at the suction hose on the main line going to the hyd pump. From time to time this seems to be a cause for poor loader performance. The ones that are bad always seem to be split on the inside toward the tractor where it can't be seen by the operator.
 
C

Corby

New member

Equipment
07 L4740 GST
May 16, 2013
9
0
0
Pickens, SC
Bulldog said:
Might also look at the suction hose on the main line going to the hyd pump. From time to time this seems to be a cause for poor loader performance. The ones that are bad always seem to be split on the inside toward the tractor where it can't be seen by the operator.
Click to expand...
I changed the filter and still no improvement, I looked at what I think is the suction tube and cannot feel any split. The filter I pulled off was grey and that leads me to believe it never had its 25 or 50 hr service. I changed the oil when I got it but should have serviced the HYD system as well.

what next?

thank you
 
Bulldog

Bulldog

Well-known member

Equipment
M 9000 DTC, L 3000 DT
Mar 30, 2010
5,440
78
48
Rocky Face, Georgia
The fluid isn't milky looking is it?

How bad are the bubbles you mentioned before? It really shouldn't have bubbles it the oil. That really sounds like it's sucking air.
 
C

Corby

New member

Equipment
07 L4740 GST
May 16, 2013
9
0
0
Pickens, SC
Bulldog said:
The fluid isn't milky looking is it?

How bad are the bubbles you mentioned before? It really shouldn't have bubbles it the oil. That really sounds like it's sucking air.
Click to expand...
The fluid is nice and clean, bubbles are small. Kinda looks like beer when poured in a glass. I agree, it is like it is sucking air somewhere.
 
B

bheineck

New member

Equipment
L4740
May 25, 2013
8
0
0
Philadelphia, PA
Hi. Just joined this site. Did you ever figure out what the cause of this issue was? I have the same stuttering of the hydraulics and it gets tiny bubbles in it. I'm guessing it is sucking in air too, but not sure where. I changed my oil and filters also with no result. I have about 300hrs and this was the first hydraulic oil change, though the one filter was changed before. This time I changed out both hydraulic filters since I have HST. I'm gonna have to look into that suction line. Seems I received some kind of notice before about that a little while after I purchased the tractor in 2007, but the service guy who came out to fix something else said I had the right hose on that wasn't an issue. Not so sure he was telling the truth now. :rolleyes:
 
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B

bheineck

New member

Equipment
L4740
May 25, 2013
8
0
0
Philadelphia, PA
Corby said:
I have no luck locating the problem. I have been traveling and have not has time to search for further leaks. Let me know if you locate you issue as I will do the same.
Click to expand...
I'm sure hoping that hose is my problem. I heard a strange air related sound coming from that general vicinity when I listened. Additionally a small amount of oil is evident on the parts below the hose. I'm guessing air is getting into the system and causing the stuttering. Guess we'll see what happens when I replace it. Hoping it is in stock.
 
B

bheineck

New member

Equipment
L4740
May 25, 2013
8
0
0
Philadelphia, PA
Hose should be here by the weekend, however I'll be participating in a tough mudder this Saturday so not sure I'll get to doing anything with it. It does make sense that is the culprit, because the pump draws the fluid from the reservoir through that hose. Since the pump is after the hose it makes sense that the fluid would follow the path of least resistance through the pump and very little would leak out of the hose, which seems to be the case for my tractor.

Edit: Given the following thread I'd say it is likely one of the soft inlet hoses prior to a pump.

http://www.orangetractortalks.com/forums/showthread.php?t=2561&highlight=hydraulic+inlet+hose
 
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C

Corby

New member

Equipment
07 L4740 GST
May 16, 2013
9
0
0
Pickens, SC
bheineck said:
Hose should be here by the weekend, however I'll be participating in a tough mudder this Saturday so not sure I'll get to doing anything with it. It does make sense that is the culprit, because the pump draws the fluid from the reservoir through that hose. Since the pump is after the hose it makes sense that the fluid would follow the path of least resistance through the pump and very little would leak out of the hose, which seems to be the case for my tractor.

Edit: Given the following thread I'd say it is likely one of the soft inlet hoses prior to a pump.

http://www.orangetractortalks.com/forums/showthread.php?t=2561&highlight=hydraulic+inlet+hose
Click to expand...
I reinspected my suction hose and found a crack that I had missed, I bet this is the problem as well.

Corby
 
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