Ford 4500 Swing slop

[oldram]

We're revitializing a 67' Ford 4500 with the 755 hoe.

It going better, (fixed the bucket spool, bad o-ring) but when we swing the arm, it does not have any good positive stop. The arm want to keep moving, overswinging a foot or so before it stops. right now it almost has to be "nursed" to get it stopped, where you want it.

The pivot bushings are worn, but I would think they would not cause this amount of swing excess.

Would they?

Since it uses the two cylinders and swing chain, is there something that can be tightened there? How about the spool control?

Any input appreciated.

 

[willie59]

Those would be two single acting cylinders on that unit. It swings the unit by pumping oil into the rod side of one cylinder while the opposite cylinder is pulled out by the chain. Stopping the swing action would have to be done by the cylinder that is being pulled out. I don't see anything in the parts pages that indicates any component to control oil flow at the cylinders, it all seems to be done by the control valve. There's quit a few components to the swing valve section, your problem is likely in the control valve, just not sure what components would be causing the problem.

Could you possibly follow the hoses from swing cylinders back to the control valve and see if there's any other valves in the swing circuit?

 

[El Hombre]

Not familiar with a 4500, but my 5550 has worn pivot bushings and it's a job to anticipate the slop and get the bucket down where I want it. Try putting the boom sticking straight out, and the dipper stick from the hoe, parallel to the ground, shut off the engine. Now shove it side to side and see how much it moves. No hydraulics with the engine off, just the mechanical slop.

Helps if someone is moving the bucket while you eyeball the pivots and anything else back there that restrains the motion. There's a lot of leverage between the pivots and the bucket, little bit of movement at the hoe is 6 inches back at the bucket, or more.

 

[daman]

are both side chains tight?

 

[mitch504]

is the crossover line from the back of the cylinders intact?

 

[oldram]

is the crossover line from the back of the cylinders intact?

This particular unit does not have a cross-over. There is a fitting on each cylinder, that has vent caps. Manual shows later models have the crossover. We were wondering what is up with that. One clyinder will leak a littl oil out of the vent, if the hoe sits for a while.

 

[oldram]

Seems my Bro may have been overstating the problem a bit.

Operated the hoe today (for the first time ever on a backhoe). Swing positions pretty well, not perfect. An experienced operator, could probably make this hoe sing. Pivot pins and bushings, would probably bring it up to snuff.

Ran great for 2.5 hours then stopped cold. We think the fuel pump screen is again clogged with crud from the gas tank (it sat for 10 years). WE tried to clean out the fuel tank as best we could, but did not have time to remove it completely, for a complete scrubbing and recoating. It needs a new fuel tank shut-off valve, so we are looking that will be an exact fit, except have a sediment screen/cup.

What a great time operating your own earth-moving equipment.

Thanks for everyone's input.

 

[mitch504]

If those vent plugs get clogged, it can make the cylinders bounce. that's why ford changed it to a low-pressure hose between the base of the cylinders.

4500s weren't themost precise in the swing department

 

[livetolearn]

That swing cylinder is leaking oil past the seals. If it gets worst you will need to change the seals. I have the same vintage machine that I converted to a low pressure hose and
a collection trap ( 1 pint plastic bottle) connected in the middle of the hose to collect any blow bye hydraulic fluid. The whole system is sealed to keep out dirt and moisture.

 

[Effinay]

I've got a 1986 NH LB 480 that has the same symptoms. However mine is a result of everything just being worn. Operating the swing requires intense concentration and a gentle touch on the sticks. As time goes by, I have been able to compensate for the short comings of my education when I bought this machine in the first place. I've been evaluating (aka crappin' myself) as I'm operating this feature and trying to determine is it worth sinking the money into, or look for something else.