how does the hyd fluid

[accordionman]

HELLO TO ALL,
on the MF 165, we installed a new pump, but it
did nothing to improve the steering. with the
engine running i cracked the pressure line, and
fluid came out. i cracked the return line, and
nothing came out. does anybody know if the
fluid circulates all the time, or is there only
pressure in the return line when the wheel is
turned. what is confusing, there are many
different versions of the power steering system.
i think our problem is in the control valve, but
i could be wrong. there are many parts on this
tractor that need to be replaced, worn bushing,
and such. i will go through this step, by step,
when i get the machine back to my shop. any
comments, or suggestions are welcome.
good luck to all.
accordionman
wlbrown
wright city, mo.

 

[Farmwithjunk]

I'm vaguely familiar with that power steering system. It's the same exact steering that's on my 150 Massey. 1st off, contact (via email) Big Dean. He'll save you a ton of time. I'd imagine the problem will be in the small valve you'll find on the top of the steering (behind the grill) It looks sort of like a turnbuckle. I dobt it's out of adjustment, more likely just not working. That's not UNCOMMON. Pump needs to be bled good to work RIGHT. Make dead certain you're using the correct oil in the power steering. It's NOT power steering fluid. Motor oil works. Most people use the hy-tran oil used in the rear end.

 

[accordionman]

HELLO TO ALL,
my friend has ordered the cd from big dean.
i hope it covers repair of the cylinder, and
control valve. yes, i am sure he is using the
correct fluid.
accordionman
wlbrown
wright city, mo.

 

[Fredex]

I have an I&T manual from when I had a 165. Pictures of the spool & ports in the control valve on top of the PS cylinder are not very clear. But based on what I could see in the diagrams AND the recommended method of testing pump pressure, I would say it is open center. That is recirculating unless called upon to change direction. That also tracks with driving experience of the beast; only time there is evidence of PS pump relief valve unloading is when forcing the steering against the locks in either direction.
Be careful cracking the pressure line with engine running. There will be around 1100 psi there with a properly operating and bled pump.
I agree with "farm"; if you have high pressure going into the control valve but no return, there is a problem in the valve. But if you had a low pressure flow in the pressure line, the pump may be cavitating in air - not bled. If the valve is plugged with old oil, varnish, dirt it may be preventing the pump from even bleeding itself let alone getting oil to the cylinder so that the entire system can be bled as Big Dean outlined. Did you check to see if valve moves back & forth with the steering wheel? Can you hear the pump relief valve actuating - like pump straining or increased engine load?

 

[accordionman]

HELLO TO ALL,
FREDEX,
i cannot hear any of the things you have mentioned.
of course my hearing is not that great, and with the
engine running it would be difficult. the machine is not
doing what it is suppose to. other than this problem, and
the loose steering shaft, the tractor is in pretty good shape
for its age. i see things that in my opinion, were poorly designed.
we had trouble getting the engine oil filter to stop leaking,
(poor design) the top of the cannister is very thin, and cuts into
the gasket, causing oil leaks. i would have made this with a wide
lip on the edge, so it would make a good seal.
thanks to everyone that replied.
accordionman
wlbrown
wright city, mo.

 

[accordionman]

HELLO TO ALL,
my friend got an e-mail from big dean. quote,
you need to get enough slack to open the selector
valve wide open before the wheels start to move with
the engine not running. what ever it takes to get this,
is what it will take to make your steering work. i have
read this over several times, and i still do not understand
this statement. any comments?
accordionman
wlbrown
wright city, mo.

 

[Fredex]

My guess is that he is talking about the sensitivity adjusting pin. It is a cone-shaped thing, with a lock nut, between actuating arm and the connecting arm. Actuating arm is "L" shaped - one leg connect to PS valve, the other connects to the long rod going back to the steering wheel area. Sometimes owners screw these down so that there is NO steering wheel play - when PS fails &they don't intend to fix it.

Check you PM please. I can send you relevant section of I&T Manual. It's OK for adjustments, repair/overhaul, but poor on diagnostics.

 

[accordionman]

HELLO TO ALL,
this machine is not made like you have described. it has a square
boss on the bottom of the crank arm, that fits into a
square hole on the arm below. there are two adjustment
screws, one on each side of the arm to take up the slack.
i have a breakdown of the one you have described,
but this tractor has the other type. would like to know if this
was their last upgrade on the MF tractors, or the one with the
pin.
accordionman
wlbrown
wright city, mo.

 

[Fredex]

would like to know if this
was their last upgrade on the MF tractors, or the one with the
pin.
accordionman
wlbrown
wright city, mo.

Dunno. The MF165 I had was a 1970 model and the PS worked as described in the I&T I have.

However it is put together, the linkage from the steering wheel must be adjusted so that the valve on top of the cylinder is opened before manual steering effort is applied to the tie-rod linkage. That must be true for both left turn and right turn which, from your description, are adjusted separately.

 

[JerryG]

On the 100 series that I have worked on, fill the pump. Start the engine. Start turning the steering wheel back and forth. Keep an eye on the pump and top up with fluid as needed. Sometimes it takes quite a while to get all of the air out.