Pump running backwards?

[lhfarm]

Trying to restore a 3pt lift system on a 1949 Jeep. The system consists of a small pump mounted on the front of the engine and coupled to the crankshaft pulley, return & pressure hoses running to the rear of the jeep to the lift. The lift assembly contains the reservoir, control valve and ram. Had the original pump at a shop, which said the pump was too worn to repair. However the pump was the same as that used on the IH C tractor. I purchased a used C pump and it appears to be same pump. Put the simple manifold on the new pump and mounted it on the jeep. No output on the pressure side.

This is a small, geared pump. Would it work, regardless of the rotation? Can I simply reverse the manifold (return/pressure lines)?

Thanks,

 

[oldnslo]

Depends on if the pump was built to be bi-rotational or not. Most gear pumps have the shaftseal cavity vented to inlet so that pressure does not build up and blow the seal out. Some pumps have the bi-roational checks to allow for this venting and some do not.

 

[J_J]

Why not just get a fan belt powered hyd pump like this.

Gear Pumps 250-058 Detailed Information

 

[lhfarm]

Depends on if the pump was built to be bi-rotational or not. Most gear pumps have the shaftseal cavity vented to inlet so that pressure does not build up and blow the seal out. Some pumps have the bi-roational checks to allow for this venting and some do not.

You can see an exploded view of the pump here - http://www.cleancomputes.com/Cub/Cu...ub-Touch Control Manual/Cub Touch Control.pdf I don't have additional information. I'm going to reverse the manifold (and the hoses) and see what happens.

Why not just get a fan belt powered hyd pump like this.

Gear Pumps 250-058 Detailed Information

J.J. - I show this jeep at tractor shows and would like to use the original setup if possible. I have other pumps, but would really like to make this one work.

Thanks,

 

[oldnslo]

In looking at the exploded parts it is difficult to tell if the pump is biderectional or not.

 

[J_J]

Are the IN and OUT ports on the pump the same size.

 

[lhfarm]

Are the IN and OUT ports on the pump the same size.

Yes, the ports are the same size.

I reversed the manifold and it still didn't move the ram. I removed the pressure side line, with the jeep not running, just before it enters the control valve and the fluid dripped out. That didn't happen before.

Is it possible for the system to be air-locked? Also, I'm not sure the valve is working correctly. I've ordered a pressure gauge and it should be here next week. I'm assuming that should be my next step.

Thanks

 

[Leejohn]

If you can! Run hoses from the in and out and put the ends in a 5 gal. pail that is about 1/2 full. Start it up and there should be flow. See if that can tell you some thing.

 

[J_J]

You will know if you have hyd flow through the valve in an open center hyd system as the fluid is always flowing as long as the pump is pumping.

The pump may not have prime.

Is the suction port connected to tank?

 

[Leejohn]

What i'm getting at is there a screen in the tank.

 

[lhfarm]

Thanks for the suggestions.

J.J., is there an easy way to ensure the pump is primed?

The inlet hose comes out of the tank and almost immediately goes over the rear axle. If the pump is worn, I assume it is possible that there isn't enough suction to pull the fluid over the axle.

I'll try to see if it pumps from the 5 gallon bucket. May take me a couple of days to get back with the results.

 

[J_J]

You can try putting some air to the tank, about 10 to 15 lbs.

Try filling the suction hose with fluid to see if you get an output.

 

[lhfarm]

The pump works! At least I got a steady flow into the bucket. I did have the manifold reversed, so that is good to know too. It is correct now. I put some fluid in the section hose and started the jeep. Got some bubbles, so stopped the engine and filled the hose as best I could.

Next steps are hook the hoses back up to the tank and control valve. For now, I'm going to reroute the hoses so they don't pass over the frame (I had said axle above but the reservior outlet is about the same level as the rear axle).

Now on to the next phase, testing the control valve.

Thanks for all the suggestions/ideas. Hope to report more progress soon.

 

[lhfarm]

Quick update. Hooked the hoses to the tank and control valve. Added more fluid to the tank and the lift arms move up and down! However, when I leaned on the arms, they stopped moving. I have some sort of leak on top of the tank. There is a return(?) hose that goes from the bottom of the ram to the top of the tank. Since the tank mounts under the body, I can't really see what is going on. So I may have to drop the hitch. Not a fun task.

A couple of questions -
1. Could the lack of lift be due to a leak somewhere or is it more likely lack of pump pressure?
2. I am using standard hydraulic fluid. The 1947 instructions for the lift calls for "5 quarts of S.A.E. No. 10 motor oil." Should I replace the hydraulic fluid?
3. I ordered a pressure gauge and will plumb it in when I drop the hitch. I'm assuming I need to get rid of all leaks before I try to take a reading. Is that correct?

Thanks for all the advice and help. I've been ignoring other, more important projects, so I may have to behave myself for a few days. It sure was fun seeing that lift go up!