NH TC40A Hydraulic Issues

[NuHollandDiablo]

Hey guys,
I have a New Holland TC40A that I have had great luck with over the years..... Not sure the exact year my grandfather purchased it but its just shy of 300 hours. Just recently upon a cold start up I noticed the hydraulics hissing and honking at me with out actuating the joy. Naturally I went to actuate the front end loader to see how it was going to react and was extremely slow and jerky in the upward position... I then let off all the cylinders of the loader and the three point and shut the tractor down.. Upon inspection of the oil level I found it to be within tolerance but a bit milky.... I went into town and picked up a new hydraulic filter and all new hydraulic/trans oil and changed.. I started up the tractor and heard the same noise that went in and out as the tractor warmed up(about 5 minutes)... I actuated the loader upward and it again jerked and was really slow then it just stopped working.... I noticed the three point and loader were not working and the noises from the hydraulic pump area went away...reading the past posts I have tried the following..

Checked the power beyond port. allen plug was tight
No hydraulic oil making it into crank case, hydraulic seal not blown

Upon start up for a second when engine just starts to run the hydraulics make the noise again and the loader and three point start to move when I engage them and then the sound goes away and everything goes dead again!!!!

Not sure how the hydraulic pump is fed?? I am assuming it is gravity fed to input side of main pump from the transmission case?

Any ideas?

 

[davesl708]

Most likely the hydraulic pump is fed from the transmission through a suction line. The suction line has a screen to block the junk from getting into the pump.
Did you clean the suction screen when you changed the filter and fluid?

Also. the old fluid is still in the hydraulic lines and needs to be flushed out as well as the air.

 

[NuHollandDiablo]

No sir I did not clean the screen... I guess I can disconnect the lines one at a time and flush them out if the pump is building pressure but im not sure if it is even turning?

 

[jimmysisson]

Was this below freezing? Possible ice in oil pickup? Is it a new condition?

 

[NuHollandDiablo]

Was this below freezing? Possible ice in oil pickup? Is it a new condition?

NO sir, it doesn't freeze very often here probably about 80*F, yes it is in new condition... How do you access the hydraulic oil pickup screen... Through an access panel in the transmission housing? Maybe it somehow got plugged....

 

[STx]

I have the same symptoms with mine, a trip to the dealer with a full fluid change and troubleshooting says I need a new hydraulic pump. Mine work slowly and jerkily so I haven't done it yet but, it's the first thing on my list once I can afford a new pump.

 

[NuHollandDiablo]

I have the same symptoms with mine, a trip to the dealer with a full fluid change and troubleshooting says I need a new hydraulic pump. Mine work slowly and jerkily so I haven't done it yet but, it's the first thing on my list once I can afford a new pump.

how many hours are on yours??? Mine has just under 300 but I am sure that the milky fluid and lack of filter change could have possibly pre-maturely worn it out...

 

[STx]

A little over 1,000. My issues started when I damaged some hydraulic lines and it ran dry. The milky fluid means it's getting aerated somewhere, and the air in the fluid is what's causing the jerkiness in the movement. That could be coming from a spot where it's sucking air into the system or it could be some obstruction in the lines causing cavitation. I'd rule everything else out first, 300 hours is really early for a failure. 1,000 is also but, I had contributing factors.