Farmall 450 Hydraulic Problems

I have a farmall 450 with power steering and have blown the pump seal out twice. This time we have had the factory flow divider rebuilt which did not solve the problem the pump still gets hot and is on constant pressure. We drilled the orfice out to.40 over with no relief from that either and we have installed a different rear remote valve with no change. The only way the pump doesn't get hot is to put the outside rear remote lever ahead to relieve the pressure . We have tried adjusting the single and double valves in the other 2 remotes which some have said is where there problems were but no change . Looking for any suggestions as to what it may be causing the pump to get hot and stay on presssure. Thanks

Sounds like there is a closed center valve somewhere in the circuit.

The pump must free flow unless there is a demand, and that can only be intermittent.

Hello Wyatt welcome to YT! Steve might be back with
info later. I am no expert on those hydraulics was
around a 300 and 350 growing up on a farm. So is
everything just the stock remote outlets capped off or
disconnected remotes or do you have something
connected to the remotes like a loader with its own
valve? Not sure, but I do not think the 50 series had
the Teledepth system with linkage that connected to a
valve, then linkage connected back to the Fast Hitch
raise and lower linkage to gauge height. Does your
tractor have a Fast hitch? If it does I take it the outer
lever operates the Fast hitch, that is how our 350 was
set up. So you are placing the Fast Hitch lever in the
lower position and that keeps the system from
pressuring up? Mostly curious if you are running other
equipment which may be set up as closed center. Wish
they would take the ..Repair.. out of the title of this
topic section. A lot of new posters drop their worst
problems off here and their section does not get a lot
of views. There is a Farmall and IH topic section here
that would have quite a few more folks that have IH
knowledge. If you want to try to post it there you can
find that topic section by using the ..Jump to.. or ..Hop
to.. drop down at the bottom of the page when you are
viewing this.

Thanks I just reposted over there with a little more information

There are 2 types of control valves, open center and closed center.

Your pump is a fixed displacement pump, which means the fluid must be allowed to move unrestricted
through the pump, through the valves, and back to the tank unless there is a demand for pressure.

A variable displacement pump allows the pump to shift to a neutral position, moving just enough fluid to
maintain a set pressure. This type of pump will work with closed center valves.

All of your valves need to be open center and always in the center position when not in use. The pump
can not handle producing pressure continuously. The relief valve is only intended to protect the system
from dead head, occasional surges, not continuously blowing by the valve! What's happening is the pump
is generating extreme heat, cooking the seals, and will eventually ruin the pump, plus wasting a lot of
gas in the process!

Someone on the IH board will be more familiar with the exact circuitry of that tractor.