hydro problem?

[roadhouse]

looking for some input here. i have a b3300 with about 14 hours on it and seems like the hst has goten a lot louder. im not sure if this is normal or if its in my head or if there is something wrong. it also seems like it has gotten jerkier on the pedal(when accellerating it will have a hard hit of speed). the jerkiness is more noticable in high. thanks for any input, john

 

[RadarTech]

looking for some input here. i have a b3300 with about 14 hours on it and seems like the hst has goten a lot louder. im not sure if this is normal or if its in my head or if there is something wrong. it also seems like it has gotten jerkier on the pedal(when accellerating it will have a hard hit of speed). the jerkiness is more noticable in high. thanks for any input, john

That sounds unusual to me...
is the fluid level ok?
and leaks?

J

 

[roadhouse]

no leaks and plenty of fluid, the fluid seemed very clean. it seems like the pump is going to me, but i dont know that much about the system yet. can anyone explain a little on how the hst tranny works.

 

[roadhouse]

wondering if i worked it a little hard before breaking in.

 

[bp fick]

When quite warm, as in you are using the FEL, or working it good; stop, and quickly check that fluid. Does it have any foam? Air bubbles?

Check this out at operational temps. This is a very important diagnostic step.

Not likely a "break-in" issue. I seriously doubt your merely using it could do anything.

 

[dex3361]

Check the hydraulic suction line for leaks. it can suck air and cause the same issues that you describe. The hydraulic suction/return line is low pressure and is usually connected with spring clamps. I would replace them with a better hose clamp and try it.

 

[roadhouse]

it pretty much does all the time. what would the air bubbles or foam mean?

 

[roadhouse]

so the niose could be the pump pushing air?

 

[bp fick]

It is not uncommon for these things to have a fitting or line leak somewhere. Air causes the bubbles and it is a very bad thing.

It creates jerkiness and noise. It is quite possible. If you find foam or bubbles, you may need to have your tractor checked by your dealer, as it is under warranty. I was fortunate to find my own leak, a finger loose fitting, but sometimes it isn't as easy to find.

 

[dex3361]

If you are sucking air into the pump suction then it is mixing into the oil. If I have HST issues I would check the fluid level, look for leaks and look for loose or cracked suction hoses or lines. Air in the fluid can cause erratic operation. I would also look at the fluid after it sits for a day or so and see if it looks milky. Milky oil after it sits for a day or 2 could mean moisture in the fluid(not likely at such low hours).

 

[roadhouse]

ill have to check it tomorrow more completly. iv already looked it over qiuckly and found nothing. can this condiion hurt the pump if i continue to use it or could it have already caused damage? if thais is the problem.

 

[leonz]

looking for some input here. i have a b3300 with about 14 hours on it and seems like the hst has goten a lot louder. im not sure if this is normal or if its in my head or if there is something wrong. it also seems like it has gotten jerkier on the pedal(when accellerating it will have a hard hit of speed). the jerkiness is more noticable in high. thanks for any input, john

it sounds as if you have air in the system - the term is cavitation-creating air bubbles which are being pushed along with fluid and as it is a gas it compresses and expands when it is released from the restriction of the valve or pump when you travel forward or in reverse which allows the compressed air in the system to release and exit the valve directing the fluid flow.

If the filter is clogged it may be collapsed or bybassing through the filter.
any pump will create a vacuum to pull fluid through it when it rotates and if the suction line is a litle loose it will suck air through the space occupied by the hose and the clampthe leak will be very hard to find as it is a suction leak.

If you feel confident enough you could use some very soapy water with lots of suds and lay a hand full of soap bubbles on the suction line connections and if the vacuum is evident; the bubbles would or should be pulled in if it is a strong enough pressure gradient due to the leak.


It would not the hurt pump this early unless itr was totally empty of fluid. The air in the system does not allow you to properly control
the transmission in forward or reverse and that in itself is very dangerous because of its lack of precision control especially when
attaching implements with a helper.


I would call your dealer and tell them you are having operating problems due to the transmission jerking back and forth when operating and the pump is whining under load while moving.

 

[dex3361]

ill have to check it tomorrow more completly. iv already looked it over qiuckly and found nothing. can this condiion hurt the pump if i continue to use it or could it have already caused damage? if thais is the problem.

I would not use it I would have it checked out. It could be a filter plugged up and starving the pump in which case it would be bad to run it. If it was found upon inspection to be sucking air around a hose connection or fitting and it went away after fixing the suction leak I would use it and not worry about it. But I would not ignore the issue.

 

[KubieTwo]

no leaks and plenty of fluid, the fluid seemed very clean. it seems like the pump is going to me, but i dont know that much about the system yet. can anyone explain a little on how the hst tranny works.

There are several good items on the Messick's site under the Service Department section that explain how an HST works. One is Driving a hydrostatic transmission

Have you owned an HST tractor before?

 

[Egon]

At 14 hours old definitely get the dealer involved in whats happening.