6640 Steering/Hydraulic Intake warning light

[Jackfr]

While operating the 6640 in 4x4, with heavy use of diff lock and loader in 20 degree weather the Steering/Hydraulic Intake warning light came on. Never had this happen before. This tractor has a tandem gear pump so I am assuming it is the main filter that screws onto the side of the transmission/pump. The light operates off of a vacuum switch next to the filter. Hydraulic oil level is ok and both hydraulic filters and hydraulic oil were changed less than 40 hrs ago after transmission repairs so I am puzzled at a blockage warning. Anyone had this problem before? Should I just go ahead and change filters or should I be looking for something else. Bad switch? Iced filter? Where its a vacuum switch shouldn't the light go out after letting the tractor sit a while and then come back on after use? Is there any other filter I'm missing besides the one on the transmission/pump and the auxilary filter?
Operators manual states:
Tractors with tandem gear pump: Steering/hydraulic intake filter- steady light indicates that the Steering/hydraulic power lift intake filter is blocked or partially blocked. Service the tractor as soon as practicable and certainly with in 1 hour of operation.

Any suggestions or ideas??

Jack

 

[RickB]

Check the filters for damage or improper seal against the filter heads. Check the oil for signs of aeration after operation. If the light only comes on when the oil is cold and goes off as the tractor warms, I'd not worry much. Oh, and if you have a Napa, Wix, or Carquest filters on it, install NH filters. There are instances where Wix hydraulic filters are overly restrictive and cause this type of problem. Slightly more viscous oil than the MC134D spec may be problematic as well.

 

[Jackfr]

Light went on after using tractor for approx 1 hr. It has NH filters and 134 oil. What would cause aeration? I'll climb under it in the morning and check filters for damage and change them out to see if that eliminates the problem.

 

[Jackfr]

Light was out when I checked tractor this morning, But I changed filters (NH) anyway and topped off Hydraulic oil (NH 134D). There was no visible damage to either filter and gaskets were alright when I removed filters. I noticed a chattering in the FEL before changing filters this went away after changing filters and topping oil. Hopefully this takes care of problem.

Jack