Case 580 1994

[Norman Lagler]

Bolts on craddle which houses hydraulic pump keep breaking when digging in hard clay with backhoe

 

[Billrog]

Motor mounts good ? balancing front bucket on 1 corner while digging ?

 

[Tinkerer]

What model 580 is it ? There are either dowel pins or bushings in the mount to maintain precise engine to hydraulic pump alignment. A disaster is going to happen if you don't repair it soon. The bores for them that I am referring to may already be elongated beyond repair. The drawing is for a K model 580.# 4 in the diagram is what maintains the alignment.

 

[alrman]

Further to @Tinkerer comment,
If those dowels or the holes for them are damaged, the alignment for the hydraulic pump coupling will not be true & damage to the coupling & pump shaft is likely.
I have also seen the engine blocks crack in near those mounting holes.
Once this problem occurs it is difficult to remedy. I have actually had to replace an engine block & had the pump mounting refaced to make things right.......

 

[JBrady]

New member here, so I don't think I am allowed to start a new thread, but my question is related to this thread. I have a "new to me" 590 SL. When it showed up on the truck, it had a hyd oil leak under the front axle. After looking at it, there was only one bolt in the pump coupling and one that had backed out. Also, the one bolt had several washers between the coupling and the pulley. I found the rest of the bolts in the compartment by the steering wheel. I put all the bolts back in (without the washer/shims) and when I restarted the machine I had no hydraulics. Sure enough, the coupling was spinning and the pump shaft was not. I pulled the bolts back out and put the same amount of washers between the coupling and the pulley and I guess there was enough spline engagement to turn the pump. This also stopped the hydraulic leak and I have been doing very minimal tasks with the hoe. Seems it has full power and speed. I am figuring a new pump is in order, but want to get the root of the problem fixed first so I don't trash the new pump shaft. Reading through these forums, I learned to check the front mounts. One side is good, the other side has the rubber, but no bolt. I'll have to pick up the metric bolt and replace that. My real question is, is that all there is to it? The 4 bolts between the mount and the block are all tight. Any reason to take these out and inspect the dowel pins? The work looks easy enough to do (this site has been fantastic for a newbie like me). I already have two new rubber mounts for the front and plan to change those out as well.

 

[alrman]

Welcome to HEF @JBrady
If the 4 bolts on the front cradle are in place, I would just leave them alone.
Chances are you will need another drive coupling as well....

 

[Coy Lancaster]

If you have a hyd. pump rebuild shop they will be able to take care of the pump cheaper than a new pump. Or they may have a reman. While you have the pump off go ahead and replace the front motor mounts and bolts.

 

[JBrady]

Thanks Coy and Alrman for the suggestions. I had already called a few hyd shops, and although none of them committed to being able to replace the shaft without seeing the pump first, I think they can come through for me.