Case 590 sm hydraulic pump

Howdy Looking if anybody ever had problem or how to solve Hrdraulic pump problem on my case 590 sm 4 years ago put a new pump on this unit because the spline stripped on the pump.the coupler spilnes had some where and the 4 bushings in coupler look good.Fast forward 327 hours later was useing machine lost all hydraulics.Look under hood can see bolt broke off from coupler to pump.Finally got it out all 4 bolts sheared off bushings very worn and poor shape.Spl
ines on pump and coupler with a fair amount of ware.Trying to figure out what going on.There a rubber mount under pump mount but it looks good .We got it drilled out and put new bushings in so that at least we could get home into shop Order new pump and coupler will be putting in next week,Any thoughts Thanks

Not a expert on this model, but it sounds like a misalignment problem between pump and drive source. Is there any way you can check the radial and axial alignment of the two? Since this is the second time, I fear you are in for trouble again unless you identify the source.

berky said:

Not a expert on this model, but it sounds like a misalignment problem between pump and drive source. Is there any way you can check the radial and axial alignment of the two? Since this is the second time, I fear you are in for trouble again unless you identify the source.

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Morning Thanks so much for your reply,Its a bit wierd as the last time we changed it The bushing on coupler were like new,and spline stripped on pump shafThis time bushings were totaly buggered and sheared bolts off .of course this break down was in middle of nowhwere,Put new bushings in coupler and and drilled out broken bolts and reassembled to get running to get home to shop.New pump and coupler will be here next week ,Once we pull it out to put new one in ,I think we will really have to take a lot what problem is ,Thanks again for you reply and hopeing that someone has had this problem and lead us in a direction to remeady it Thanks again

Have you checked the engine and transmission mounts for looseness or failure of the rubber bushings ?
The pump input shaft can sometimes be replaced cheaper than a new pump.

Welcome to HEF @Fisher5
The front engine support (#1) that holds the pump, is connected to the engine block with 4 bolts (#2).
Are they tight & in place?
That support is also doweled (#4) in place to be certain it is in inline with the crankshaft.
If the support mounting bolts have previously come loose or broken, (which is not uncommon on the SM) the dowels/holes maybe damaged, causing mis-alignment.
Even if the mounting bolts are in place & tight - I would be removing the pump & support bracket to check those dowels

I'd do what Alrman says, we had many a mount come loose or break bolts off. Pull it off and realign

I'd definitely listen to Alrman. I had a very similar issue with my 590 SL. My dowel pins were good, but one of my 2 mounting bolts (#5 in the diagram above) were broken. Fortunately, I caught it in time to not damage my pump.

This problem is one of the reasons Case moved the hyd. pump to drive off the tranny.