Hydraulic Pressure on 640

[RedDawg]

I've a 1955 640 with the original vane pump. When it gets warm it struggles to lift the FEL with fresh fluid and all. I've thought about swapping out the pump as it is probably tired. I've thought about simply using a heavier fluid. But I figure I should do some diagnosis first. I've got one of these now http://www.harborfreight.com/5000-psi-filled-gauge-68252.html. But I have a couple of questions.

Where's the best place to hook it up? I've got a single remote. Should I put an adapter on the gauge to use the remote? If not that, where should I connect it? That will tell me what connector I need. Thanks.

 

[souNdguy]

get it in a remote and deadhead it.

 

[mhb@ufe]

Does the loader operate from the tractor hydraulic pump or does it have a front mounted engine pump?

Mark

 

[Jimmyjack]

Post back what you get. I just replaced a 1955 vane
pump that I got 2000 pounds out of, but the system
was weak. Went through the rest of the system too,
and not really sure if the pump was the problem.

 

[Dean]

Easy if you have a remote. Simply plumb your gauge into the (dead headed) remote.

Do this when the oil is fully up to temperature.

FWIW, there is nothing wrong with the vane pump. Indeed, the vane pump has its advantages.

Parts are still available (as of 4 or 5 years ago), though expensive.

Dean

 

[NNP]

agree with Dean, that the vane pump is actually pretty good when it is working well.
The adjustable flow control is handy sometimes.
They do seem to like the original spec oil (thicker) a little better than the new 134 stuff. Piston pumps ain't as fussy.

Red Dawg, You do have the flow control set to max flow, right?

 

[RedDawg]

Thanks for the input, guys. Should be pretty easy to deadhead it. I'm going to do some running around this morning and I'll get the parts.

NNP, yes, I have the flow control open all the way. But, when it gets warm that fluid gets real warm and thin. I get little lift when that happens. That's another reason I was thinking a slightly heavier - but still in spec - fluid. The hot fluid tells me the pump is warn too. But, before it's warmed up it will lift a lot. I lifted a 1000+ lbs cultipacker off a trailer one morning. Shocked the crap out of me. Thought I was going to have to drag it off.

Jimmyjack, I'll post results but it may be next weekend before that happens. I wrote myself a note.

 

[souNdguy]

if it has power when cold but not hot.. then pressure test both ways.

good cold pressure tells you that the relief is probably fine.

While i'm not a fan of bandaid fixes.. if you are just looking for a lil more use out of it before rebuilding the expensive pump.. or swapping to piston.. then thicker oil could be an option for a bandaid i guess.

all depends on what your goal is.

 

[RedDawg]

Got some initial readings. When cold it is at about 2200 psi. I warmed it up some but not all the way. Only ran it about 20 minutes and it wasn't a really hot day. But after that time it dropped to 2000 psi. As I use it more over Memorial Day weekend I'll post back.

 

[RedDawg]

Okay, got better numbers from this old vane pump. When it is first fired up and fairly cold I'm getting 2200 PSI. After it gets good and warm I'm getting about 1000 PSI and it falls fast - not much lifting power.

I'm using a UTF and it is getting pretty hot. I suppose a worn pump could cause that and also cause the lose of pressure. Am I looking at a new piston pump? What about a heavier hydraulic fluid? Could it be the lift cover? Any advice would be most appreciated.

Thanks.