W400 hydraulic pump question

IHWhitney

Member
What would cause the hydraulic pump on a
w400 gas to intermittently moan then get
smoking hot? Drove 2 miles hooked up the
swather hydraulics to test it ( got this
tractor for parts decided to get it going)
it lifted the swather fine, unhooked it,
pump started whining/growling and got
literaly smoking hot. I shut it off for
half hour, drove home no pump noise and it
didn't get smoking hot?
 
I Cleaned out the system new oil and new screen in the reservoir. Does the pressure regulating valve need gone thru? Plumbing is not complicated in this one, only one spool/ valve.
 
The hydraulic system is not a closed system. And not a true open center system either. It is a demand driven system. There is a pilot spool valve in the Regulator Safety block (to the left of all control valves) this pilot valve controls the application of system pressure. It has a small screen ahead of it, and sometimes a check ball, and an drilled orifice through the center. When a control valve lever is moved, the pilot valve senses the pressure change and closes a port to the reservoir. This pressurizes the system and the hitch and remotes work. When the control valves are centered, the pilot valve moves and dumps all but a tiny pressure to the reservoir. There are four things that cause the situation you had happen: The screen can become plugged and collapse, the orifice can get plugged up, the ball can (over time) smash the entry to the orifice and restrict it, and the pilot valve can stick in either position No pressure or full pressure. If full pressure from any of these causes the system is effectively dead headed and the pressure relief (in the same block) will limit the max pressure but the system will quickly overheat. The ball can be taken out. The screen cleaned and replaced, damage to the orifice can be drilled out. The orifice in some was too small to begin with, and can be drilled out to one number drill larger in diameter than original. Parts 7 8 and 10 See diagram attached. Jim
diagram
 
Jim, how sure are you that the W400 utilized the pilot operated hydraulic system similar to what a Farmall used. Maybe Fritz or rust red can chime in with more knowledge. I want to say if one of these had hydraulics it would be more like the Super M square cast reservoir right behind the belt pulley. To the original poster would you say the system looks like it was added to the tractor or does it look factory?
 
I'm fairly confident it's identical to farmall systems. The only difference i see is the reservoir is shaped different(indented in the back bottom) to accommodate the steering box. I added hydraulics to my w400 diesel off a farmall 400. The gas one pretty sure is original. The regulator valve body does Not have the provision for pwr steering. Is there a screen anywhere besides in the reservoir? I'm sure it had been run without one for sometime before it was parked to rust stuck! It didn't have an oil filter in the motor canister either!
 
I dont know anything about that system, the symptoms sounded to me like constantly over relief, or some kind of intermittent restriction, inasmuch as it went away after it cooled off. Either that , or the pump is already smoked. In any case, sounds like Jim nailed it.
 
all i know is that if the oil is pumping over relief the oil will get smoking hot. not really any other reason why it will get hot.
 
those are a factory system with the tank and controls right in front of the dash. better set up than the w6 and M'S
 

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Back
Top