Do I need to bleed hydraulics after running out of fluid?

[CaptainL]

I have a Universal skid steer loader I believe is around 1967(before Case took them over). Model 150M. I believe it is very similar to the Case 1530 loader first made in 1969 after the takeover. I use it for snow removal and during this big blizzard in the NE, I lost my hydraulics. I had noticed a slow leak but it has been just too cold for me to get into this before now. So when I lost the hydraulics halfway through my plowing job, I guess some would say I had it comin'.
I picked up 5 gallons of Amalie ISO 46 and added it to the tank anticipating the system would start pumping again, but it wouldn't.
Can anybody tell me if the pump is gravity-fed from the tank? will the pump self-prime from the tank? Is the system self-bleeding or does this pump or the system have a bleeder valve?
Perhaps the question is best asked, how do I troubleshoot the loss of hydraulics and rebound from running it dry?

 

[J_J]

Best answer is, do you have fluid at the pump in port.

Check any strainers and filters.

The hyd should self purge/bleed as you cycle through the hyd system many times.

 

[CaptainL]

Best answer is, do you have fluid at the pump in port.

Check any strainers and filters.

The hyd should self purge/bleed as you cycle through the hyd system many times.

Thank you for your quick response. I have the machine in the garage, jacked up with the wood stove cranking. I found the drive input shattered on the pump. Not sure what the assembly should look like but I have about half of a bowl-shaped casting with a gear molded into the bowl, loose on the frame where the pump bolts in. So that leaves another bowl-shaped coupling on the drive shaft, unattached to the pump. Can you direct me to where I might get a schematic of this hydraulic pump and drive so I can determine what should be there and what I need to order to get her together again?

 

[CaptainL]

Thank you for your quick response. I have the machine in the garage, jacked up with the wood stove cranking. I found the drive input shattered on the pump. Not sure what the assembly should look like but I have about half of a bowl-shaped casting with a gear molded into the bowl, loose on the frame where the pump bolts in. So that leaves another bowl-shaped coupling on the drive shaft, unattached to the pump. Can you direct me to where I might get a schematic of this hydraulic pump and drive so I can determine what should be there and what I need to order to get her together again?

Okay, I have spent some cold time on my back and assessed the damage. The drive for the pump is a rubber gear-shaped clutch sandwiched by those bowl-shaped castings previously mentioned. The bowl on the drive shaft split in half and the rubber clutch shattered. I am not sure if the pump dried out and tightened up to cause this, but I was able to easily turn the pump by hand, so at least it isn't seized.
I removed the mount bolts for the pump with the intention of trying to move it away enough to be able to pull the broken bowl from the drive shaft, which is on a key way with two set screws. The pump doesn't want to just slide away as the hoses are pretty rigid, so I may have to drain the oil and remove the hoses from the pump and take it right out.
I think I will get through this ok, as soon as I can find a source for the parts I need. Any suggestions on that?

 

[Xfaxman]

Pictures would help, as I don't have a clue what you are talking about.

If you take the pump off, a hydraulic shop can test it and they might have the broken parts that you need.

Here are two online sources.

Surplus Center

Bailey International | Mobile Hydraulic Solutions

 

[CJONE]

If you actually did run it completely out of fluid, the pump could have seized and then when it cooled off freed up. Replace the coupler and put aw32 in it, not 46 for winter use. If it is a open system, it should self purge like JJ said but I would crack the suction line on the pump to be sure it had fluid and if not gravity fed, fill the line and pump suction port with fluid before cranking it up. If the pump is not damaged you should be ok. Just replaced a pump on a forwarder that a customer ran out of fluid. It was only $1600 so hopefully you are not in the same boat! CJ

 

[muddstopper]

Is this the type of coupling between your pump and shaft. LOVEJOY COUPLERS -

 

[Xfaxman]

------------- I found the drive input shattered on the pump. Not sure what the assembly should look like but I have about half of a bowl-shaped casting with a gear molded into the bowl, loose on the frame where the pump bolts in. So that leaves another bowl-shaped coupling on the drive shaft, unattached to the pump. Can you direct me to where I might get a schematic of this hydraulic pump and drive so I can determine what should be there and what I need to order to get her together again?

Your description doesn't sound like a Lovejoy type, but they are the most common.

 

[CaptainL]

Your description doesn't sound like a Lovejoy type, but they are the most common.

View attachment 409456 View attachment 409457

I haven't done anything more for the last two days as it has been in the single digits and wrenches freeze in my hands. Thank you for the picture of the love joy coupling. Though that's not what is in my loader presently, if I found one with the right keyed shaft size, I may need to adapt to that.
While I have been housebound in this cold and snow, I found a parts manual in Microfiche on eBay, so I am looking forward to receiving that. I have also found a company that will convert the microfiche to a PDF file so I can print it out as a hard copy manual for myself, and make it available to others. Let you all know how that works out.
As soon as I get the hydraulic oil drained down, the lines off the pump and the pump out, I will post pictures of the clutch and try to vindicate my description. In the meantime, I really appreciate everyone's participation and support. Thanks folks.

 

[CaptainL]

Thanks for the tip on Lovejoy Couplings. I spoke with a friend locally who advised to go to Grainger too. I looked up Lovejoy couplings and found mine. It is called an S-Flex Shaft Coupling made by Lovejoy. As soon as I remove this pump, I can measure the shaft size and order the complete assembly which includes the left and right cast bowl gears and the rubber insert.
I am awaiting the delivery of my Universal skid steer Uniloader parts manual in microfiche and have found a company who can convert this to a PDF for me. From that, I can print out copies of the manual for anyone interested. This is a great find as I have never found a parts manual for this Uniloader before now.