can these pumps be reversed?

[sundown57]

Need help reversing direction on these pumps. I have searched for weeks and can't find much info on it. I think because these are the older cast-iron style they do not make their own charge pressure. so is it true if I reverse the small front pumpit will supply charge to the 2 big ones so they can run in either direction? And would I have to reverse the lines going to the motors? Need all the info i can get. thanks in advacne.

 

[mitch504]

What are they on, and what are you trying to do?

 

[sundown57]

they are in a bobcat 720, it has a Wisconsin motor that runs off the front. so the pumps turn CCW. I want to repower it with a Kubota and i want to run it off the flywheel. so I need to figure out how to reverse the pumps

 

[partsandservice]

You would only have to reverse the charge pump. I would think that little pump.on the end is not the charge pump but the hydraulic pump. The charge pressure would enter the drive pumps through the filter in your pictures.

 

[Welder Dave]

Pump on front is generally to run the hyd's. I think you need to find out what brand and model of pumps and see if they are reversible. Then a bunch of lines would need to be changed. Maybe looking at other Bobcat 72X models with different engines could point you in the right direction.

 

[Tones]

Not all pumps can be reversed unless the internals are changed. Without doing this it going to cooosssstttt you.
Question, why not drive the pumps off the front of the new engine?

 

[Tones]

Most pumps are directional and big job to change, they have to fully pulled apart and new lens plates fitted. It would be far easier to drive them off the front of the new engine

 

[sundown57]

You would only have to reverse the charge pump. I would think that little pump.on the end is not the charge pump but the hydraulic pump. The charge pressure would enter the drive pumps through the filter in your pictures.

the small pump in the front does wrap around and tie into the filter. so yeah i believe thats the charge pump Plus its the only other pump there is .

 

[sundown57]

Not all pumps can be reversed unless the internals are changed. Without doing this it going to cooosssstttt you.
Question, why not drive the pumps off the front of the new engine?

the kubota is externally balanced so you can not change the crankshaft pulley and the one that's on it is way too small to mount the pumps to. also running them off the front is just plain wrong.

 

[Vetech63]

The 2 larger pumps are the hydrostatic drive pumps for your travel. The small pump is the implement pump that drives your control hydraulics. That is an older Sperry Vickers system.

 

[Vetech63]

Also, that implement pump is a vane pump and is designed to run one direction only. You will need to find an engine with the proper rotation to use this pump system.

 

[sundown57]

well, it's about 50-50 so far, a lot of people say just swap the center part of the vein pump 180. and the other pumps don't care what direction they are in. same amount say it cant be done.

 

[Vetech63]

well, it's about 50-50 so far, a lot of people say just swap the center part of the vein pump 180. and the other pumps don't care what direction they are in. same amount say it cant be done.

The suction side of the vane pump is larger than the discharge side. Its designed this way because the discharge port helps restrict the hydraulic load at the discharge side of the vanes and helps the oil flow under pressure go in the proper direction. By reversing that, the vane cartridge will be exposed to higher pressure due to the bigger opening on the suction side. It will not create the pressure needed to run the implements properly. Even the vane tips have a bit of a scrapper angle to them which ensures they move as much oil as possible....in the proper direction.

Is the original engine not repairable?

 

[Vetech63]

....and you are correct........the hydrostats don't recognize direction of charge pressure, they only need to see it in flow and psi.

 

[partsandservice]

Not all vein pumps can be reversed but if it has a removable cartridge it can be flipped . The suction and discharge pump remain the same. Tigercat bunches and barko loaders ran the vein pumps in the past and I have installed new pumps that would do nothing and would have to flip the cartridges to make it work. Have received two cartridge pumps that one cartridge on the wrong rotation. Half of the knuckle boom worked!

 

[partsandservice]

 

[Vetech63]

Looks like this old dog learned a new trick! LOL Well done my friend.

 

[sundown57]

Found some numbers but can't seem to find any info on it.

 

[partsandservice]

Vetech63 I have also been making a living on the wrench for 30 years or so. 27 self employed. After all that time you would think one would have seen it all but I am still gaining knowledge. Gained a bunch of new knowledge through the diesel emissions debaukle.
Sundown57, that is a vickers pump and likely could be flipped.

 

[Vetech63]

Vetech63 I have also been making a living on the wrench for 30 years or so. 27 self employed. After all that time you would think one would have seen it all but I am still gaining knowledge. Gained a bunch of new knowledge through the diesel emissions debaukle.
Sundown57, that is a vickers pump and likely could be flipped.

Well, when we quit learning, we're dead.