[AT] IH 504

[Greg Hass]

I haven't seen any replies to this post so I will give it a try. In my 
opinion, adding a filter in the return line is like locking the barn door 
after the horse is gone. I would say that 95% of  any damage to a hydraulic 
system is done by things going through the pump and valves without being 
filtered out.  My dad bought a 504 new when they were being sold.  We had it 
for many years. I don't remember exactly what the filters looked like, but 
they were on the SUCTION side of the pump. I believe there was a fine mesh 
screen before the filters. This way any dirt that enters the system should 
be caught by the filters before it gets to the pump and valves. I believe 
all IH tractors since the 340's and tractors of that era have filters in the 
suction line. I don't know about all other tractors, but I do know that many 
of the Fords had the filter after the pump. A neighbor had one, I don't 
remember the number, but it was in the thousand series. The internal brakes 
went to pieces and before he knew what was wrong, it had destroyed the 
hydraulic system. He said that when he fixed it there was a kit available to 
put the filter before the pump. Not sure of all the details as this was 15 
years ago. Another neighbor had a Ford industrial loader tractor, fairly new 
as it had the modern type of front wheel assist. The gear that ran the front 
wheels, or the bearing on it, went to pieces and the metal chips destroyed 
the hydraulics. He replaced many parts, but never could get the 3 point 
hitch to work properly even though he had the dealer work on it several 
times. He finally gave up and about 3 years ago traded it for a new tractor. 
Again, the filter was in the return line. On the other hand, about 7 years 
ago, I was plowing with my IH 856, when I lost the power steering. I went to 
the yard and opened up the housing that holds the filter. The screen was 
completely plugged with metal chips; not a good sign. I cleaned the screen 
out good and returned to the field. One trip across the field and the 
steering quit again. Back to the yard; screen plugged again. Done for the 
season, it was already fall. That winter when I took it apart, I found a 
double roller bearing on the rear end pinion had ground itself into pieces. 
I repaired the problem, cleaned the rear housing out, put new oil in and 
changed hydraulic filters. Its been over 5 years and I have no hydraulic 
problems. My opinion, keep the filters that came with the tractor changed 
when called for and enjoy your tractor.
Greg Hass
Michigan