[AT] tractor hydraulic pressure measuring? Dean

[drupert at seanet.com]

This sounds about right to me as well.  I have a T035 and a MF35 and both
have Davis Model 101 Loaders with front pumps.  One pump is a Cessna (and
the other is some aftermarket).  The Cessna Pump has a working pressure of
2150 PSI.  The Davis spec for the Model 101 with the Cessna pump shows a
lifting capacity of 1500 lbs at full height and 2300 lbs at half height. 
The lift cylinders have a bore of 2-1/4".

Dudley





> Cecil R Bearden wrote:
>> The early tractor's relief valve was replaced with the later relief
>> valve with no problems.  I cannot find a reference to the pressure of
>> the to-35 pressure, but the MF-35 was 2800 .  The valve was usually
>> referred to 2750.  This seems to be correct in my memory of working on
>> the early Ferguson and fords.   I spent a lot of hours in a tractor shop
>> working on the hydraulics.   I would suggest looking to see if you have
>> a control valve that has another relief in it that could be allowing the
>> oil to bypass the control and go back to sump when you load it above
>> 1750 psi.
>>
>> Early loaders had about a 2 in diameter piston in the cylinder and the
>> cylinder operated at a 45 deg angle usually.   If you work on the 300
>> psi difference, and take the area of the piston, it figures out to 1884
>> lbs of thrust combined.  At a 45 degree angle, this would be the cosine
>> of 45 (.707) x 1884 = 1331 lbs to raise a load.  This is about 1/2 yd of
>> sand, and that is about what the old tractors would handle.    It sounds
>> ok to me......   A large round bale or hay would be nearly flatten the
>> early tires. The rear tires would have to be ballasted and then put a
>> box blade on the rear also.
>>
>> I am sure someone will try to  shoot holes in my figures, but it is a
>> close approximation.
>> Cecil in OKla
>>
>>
>
> Sounds about right. I'm just wondering if this is the tractors system.
> John says his tractor has a "front mount pump" The 35 I have has an
> internal pump for the hydraulics.
>
> I've seen more than a few broken axles/spindles and front castings from
> heavy loads on these tractors. They are a handy tractor but loaders are
> not really fun on them. Especially the ones that don't have power steering
> !
>
>
> --
> Steve W.
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