TC40D HST oil filter seal blowing out

[RickB]

This is an ongoing problem with NH compacts that goes back to the 20 series. The problem is exascerbated by a change to the charge pressure (hydrostatic) filter which resulted in less filter media area and presumably greater pressure drop across the media. NH's current "cure" is a $60 filter that is built to withstand greater charge pressures than the standard filter. Oil cooler failures on Class III tractors and cooler hose failures on Class II's as well as 20 series hydro tractors are closely related to the current filter fiasco. The entire cooler/charge pressure circuit is underdesigned for the pressures at cold start IMHO.

 

[jinman]

Thanks for the info, Rick. I've always wondered why NH didn't put the cooler and filter on the input side of the charge pump instead of the pressure side. I guess that would make the charge pump more likely to cavitate if it was starved of fluid because of the long input circuit plumbing. Perhaps the best solution might be a relief valve that would allow fluid to return directly to the reservoir in an overpressure condition. Do you know what pressures may exist in a cold start condition?

I can understand that the overpressure is related to the current rash of hydrostatic cooler failures. I'm just surprised that this is the first time I've heard of the HST filter blowing like this. I'm still thinking there might be some obstruction in this fellow's system. /forums/images/graemlins/confused.gif

 

[fcchip]

Finally called enough dealers to find some info. Major dealerships not the small ma and pops place where I bought my tractor. I was told that New Holland recommends a different HST oil filter for cold weather, below 32 degrees. Part number is SBA-340500980. Its been down to 25 at night here in WI. I've told the dealer where my tractor is at and they ordered and installed that filter. Sounds like the problem is solved.
I don't have the tractor back yet. Still has a couple small problems they are working on, safety switches. If this doesn't work I think the oil passage being blocked or pressure relief valve sticking will have to be checked out.
Thanks for all the help and ideas. What a great website this is. I wish I had found it earier. I'll update if any changes.

 

[Soundguy]

Gee.... I think I'll add this to my gear vs hydro 'care' packet.. for when the next time that thread comes up... this certaintly sounds like it can be a ligitimate 'con' to throw on the pile, as I havn't heard of too many gear trannies blowing a filter in cold weather /forums/images/graemlins/grin.gif

Soundguy

 

[JerryG]

Come on now Chris. You know that they do it all the time. /forums/images/graemlins/grin.gif

 

[Soundguy]

</font><font color="blue" class="small">( Come on now Chris. You know that they do it all the time)</font>

hey.. it's been a good day.. i found another tidbit in another thread. A HST user was having difficulty in figuring out groundspeed to determine seed/fertilizer spread rate... No set speed, based on gear range, and engine rpm as with a gear model.

At best I heard comments of use max 'pedal' in that range and then calculate from there.. or use gps device.. etc. /forums/images/graemlins/grin.gif

Soundguy

 

[JerryG]

<font color="blue"> At best I heard comments of use max 'pedal' in that range and then calculate from there.. or use gps device.. etc.
</font>
Tricky at the best. /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif I am loosing it anyway. When I first read your post I thought it said vise grips not gps. But, I guess that would work too. /forums/images/graemlins/grin.gif

 

[kensfarm]

That's the problem w/ cone-type spreaders.. my old grain drill w/ seed boxes has lb/acre settings.. just set them and go.. flow rate adjusts to the speed you go.

I wonder if pre-filling the filters helps any?

 

[Reg]

Any further news on this ?
If you need a "wnter" filter and a "summer" one...
doesn't that translate to TWO filter changes a year ?
I'm assuming the winter one is coarser than the summer one, so you would want to use the summer one when you can and the winter one when you have to.
Not that you'd HAVE TO change all the fluid every time, but it seems for cold climate use you'd want the right filter in.

 

[RickB]

I think you are making an assumption based on a hasty conclusion. I have read or heard nothing to indicate the winter filter has less restrictive media. The seal and base of the filter are different as well as the housing itself. It is designed to be a charge pressure filter whereas the current stock filter and its predecessors are more of the typical automotive spin-on design in terms of the seal and outer construction. A quick visual comparison or even hefting the two will verify this. There is no valid reason to change the 'cold weather' filter prior to the recommended 300 hour interval.