# Hydraulic pump motor - how to remove pump?



## WCastle (Jun 13, 2008)

In one of those junkyard find moments, I now have all 4 motors from a Clark Forklift and the main lift pump motor has a pump that I am not sure how to remove.

Does anyone have any knowledge as to how the drive gear is attached in one of these?

The pump housing is secured with 2 - 3/8" fine thread allen screws, the pump housing has 4 - 3/8" bolts holding the halves together, all have been removed and there are no apparent c clips, pins, screws etc... holding the drive gear on the shaft, I know it was put together and somehow comes apart.

Pics could be posted of the dilema if needed, I do have past experience in a shop rebuilding electric motors but most were starters and generators and had no pumps attached


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## major (Apr 4, 2008)

WCastle said:


> In one of those junkyard find moments, I now have all 4 motors from a Clark Forklift and the main lift pump motor has a pump that I am not sure how to remove.
> 
> Does anyone have any knowledge as to how the drive gear is attached in one of these?


Hi and welcome WCastle,

What motors you got on those? At any rate, the motor typically has an internal splined shaft. The pump has an external mating splined shaft. The two just fit together and the pump housing has a pilot to mate to the motor end bell to center the thing. All can be a pretty tight fit. In a perfect world, after the bolts are gone, the two should just fall apart. But.....the splines are steel to steel, should have been lubed at assembly, but may in fact be pretty well rusted together if they are old. You might try heating the whole thing up to about 250 F. The outer parts expand a little more than the inners. Motor insulation is good for at least 300 F.

Good luck,

major


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## WCastle (Jun 13, 2008)

Dont see much in the way of rust, and not sure what model it is, the tag is wasted, looks like it was silk screened and now is just shiny.

The unit was a 36V Clark. perhaps these pics will jog someones memory.

as a last resort I could heat the gear, but I figured I would wait.


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## ww321q (Mar 28, 2008)

WCastle said:


> Dont see much in the way of rust, and not sure what model it is, the tag is wasted, looks like it was silk screened and now is just shiny.
> 
> The unit was a 36V Clark. perhaps these pics will jog someones memory.
> 
> as a last resort I could heat the gear, but I figured I would wait.


pic # 1 inside of hydraulic pump ?
pic # 2 motor case looks about right . 
pic # 3 tape measure at the 4" mark ?
pic # 4 case diameter 7" ok for something light maybe . 
How many brushes does it have ? 
What does the commutator look like ? number of bars . 
Would like to have seen the attaching point of the pump to the motor end plate . May be ok what do you plan on using it in ? J.W.


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## ww321q (Mar 28, 2008)

ok! pic # 4 commutator bars ! I just walked over to the shop to take a look at my motor and the one you have may be the same . Got 8 angled brushes ?
Jim Husted from Hi-Torque Electric said mine would be good for a light car or truck with a transmission and a blower would needed to be added as you would be working it hard . J.W.


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## ww321q (Mar 28, 2008)

My motor J.W.


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## WCastle (Jun 13, 2008)

Thanks !! 

That tells me exactly what I needed to know to get the pump off the shaft.

And yes it looks like the same, 8 angled brushes approx 1/2" x 1 1/8" , fields are series wound approx 7/16" copper ribbons.

Do you have the specs other than just 36V?


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## ww321q (Mar 28, 2008)

NO specs but Jim Husted "Mr. Forklift and drag motor expert" said it would work but it is small so I would be working it hard ! (reason for extra external cooling fan) What kind of car are you thinking of building ? I'm starting off at 72 volts and will upgrade to 120 volts later . J.W. 
http://www.youtube.com/watch?v=5umhV_84VJo


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## WCastle (Jun 13, 2008)

Well I got the pump to come off, someone had used thread lock on it!

Now to drill some holes for the teflon insulators for the feild connectors, do some spot welding on the studs and all of that fun stuff.

A little bit of machining on the brush plate mounting surface, mount sensors, fabricate the VBT stepper linkages, and of course the cooling for the commutator end, as suggested by the expert.

Next will be the coupler for the drive end, and a carrier bearing for the primary on the cart.

I guess that is enough projects for the next few days 



> What kind of car are you thinking of building ?



Well it is going to be from scratch, but mostly recycled GM parts.

The first EV for testing with this motor will be a Yamaha golf cart/mini truck, good access to all of the drive train for evaluating my ideas is essential.

The long term goal is as follows...(some components already done)

HSCHEV (hydrogen stirling cycle hybrid EV) 

Field switching and VBT proprietary controller.(asking for suggestions as to which features EV'ers would like to see in a new controller)

Starting with lead but plan to switch to LiPo (or whatever new technology proves better)


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