CAV injection pump preventive maintenance

[Destroked 450]

Even if that were the case, once the governor forces a sticky valve closed, the motor is still dead because it's no going to open again. So whether or not the stop cable is pushed in is pretty much a moot point. Would be better to solve the problem since there is a significant number of pumps with ESO's, which hold the valve closed when no power is supplied.

I’m not an expert on the operation of a CAV pump but the only sticking issue with the metering valve I’ve ever heard about was when left in the closed position for extended periods of time
I have not experienced this myself with any of my tractors

 

[sotxbill]

Even if that were the case, once the governor forces a sticky valve closed, the motor is still dead because it's no going to open again. So whether or not the stop cable is pushed in is pretty much a moot point. Would be better to solve the problem since there is a significant number of pumps with ESO's, which hold the valve closed when no power is supplied.

If,, you store the tractor in the ON position, then its more likely to stick in the "on" position..
but yes,, if it happen to stick the instance that you turn off the engine, you need a rebuild.. however if its still moving to go off, its MOST likely to be still moving to go back to the on position.. "Its the long sitting" that lets the goo dry up and stick it. But once it starts and gets washed down in fresh fuel, its soluble again. ouch.. if you followed this statement, I apologize.

 

[Fritz Maurer]

If,, you store the tractor in the ON position, then its more likely to stick in the "on" position..
but yes,, if it happen to stick the instance that you turn off the engine, you need a rebuild.. however if its still moving to go off, its MOST likely to be still moving to go back to the on position.. "Its the long sitting" that lets the goo dry up and stick it. But once it starts and gets washed down in fresh fuel, its soluble again. ouch.. if you followed this statement, I apologize.

The metering valve can hang up at any point in its rotation. It requires only a slight touch to rotate it... hence the very light spring incorporated into the linkage. My point was, if it does stick open, and the governor forces it closed, the force required to open the valve again will merely stretch the spring. Just because the governor closed the valve does not mean the trouble is over. It's still bound up either by goo or corrosion. Since op's tractor is a 4000 Ford, it is not likely the pump drained out dry. So the theory of the fuel dissolving the goo is n/a. The trouble, whatever it is, is in the fuel.

 

[sotxbill]

The metering valve can hang up at any point in its rotation. It requires only a slight touch to rotate it... hence the very light spring incorporated into the linkage. My point was, if it does stick open, and the governor forces it closed, the force required to open the valve again will merely stretch the spring. Just because the governor closed the valve does not mean the trouble is over. It's still bound up either by goo or corrosion. Since op's tractor is a 4000 Ford, it is not likely the pump drained out dry. So the theory of the fuel dissolving the goo is n/a. The trouble, whatever it is, is in the fuel.

BUT.. IF the governor can force the metering valve closed, then its not stuck, is it... it only sticks while sitting for long periods of time.... So the chance of it sticking while running are pretty slim to none. Your turn.

 

[Fritz Maurer]

BUT.. IF the governor can force the metering valve closed, then its not stuck, is it... it only sticks while sitting for long periods of time.... So the chance of it sticking while running are pretty slim to none. Your turn.

Gum. The metering valve doesn't magically become free because the governor forces it in one direction. The valve may still be sluggish ... stiff enough that the little spring cannot pull it back open.

The valve remains submerged in fuel on Fords and many other tractors with the tank above the pump. So how does that fit in with your thinking that the fuel will dissolve the gum that is making the valve stiff? Whatever is in the fuel is causing this otherwise why is there all this talk of adding motor oil , atf or whatever else to prevent
this?

Whatever is occurring to make the metering valve drag, can also happen to the plungers. Once they're stuck, it doesn't matter in what position you left the stop cable.