'67 Case 580 CK - bucket curls, but low on power (for full bucket load)

JohnnyAirtime · Mar 22, 2017

Hello folks...

My "new to me" tractor is getting some use, and I'm learning... slowly, but still learning.

It has a backhoe attachment, and a full gannon attachment. Both working fine, or so it seems.

However... the problem I think is with the "curling" power of the bucket.
The bucket will curl... but not very well. If I'm scooping a full load of dirt, the bucket won't curl. I have to lift the bucket so that it's not so full and drops some of the dirt, and it'll eventually curl if NOT a FULL bucket load. All of the other hydraulics work good, and I don't have a problem lifting the bucket... just with the curl itself.

I also added forks to the bucket (at one point), and I know this adds leverage to whatever I'm lifting... but, I curled a concrete picnic table with the forks and it BARELY was able to get it off the ground (when curling). In fact, it wanted to slowly drop the weight or "un curl" as soon as I got it level or off the ground by raising the bucket.

Am I expecting too much for such an old machine? Or, is there something I can look into that could be a limiting factor?

The previous owner told me the "pump" was recently replaced. Not sure what that means to him... hours ago, or years ago could be "recent". And I'm not sure how to tell if it's been replaced or if it's in good shape or not. Also, as I understand it there's "valves" that play a part in all this... so, I'm all ears if there's something I can look into to possibly strengthen the 'curl' capability.

Thanks in advance

Billrog · Mar 22, 2017

I wouldn't be concerned about the pump if the rest is working. Could be in the spool valve for the curl function. Or the seals on the ram. Or what others suggest.

JohnnyAirtime · Oct 30, 2017

Billrog said:
I wouldn't be concerned about the pump if the rest is working. Could be in the spool valve for the curl function. Or the seals on the ram. Or what others suggest.

Just checking back in on this....
As I was using the tractor for moving dirt, rocks, etc. Had a power steering line blow a hole... so, heading to the local hydro hose place to build some new ones. And, realized I never came back to see if there were any responses here. I was also using a rented Bobcat S510 that could haul more dirt then my 580... just because of the lack-of-curl, and not being able to get a full bucket scoop.

Spool valve? Is this something that can be checked, cleaned, etc?

I'm guessing it'd be best to buy a service manual... I need to start a maintenance schedule on 'ol Betsy.

Anyone else have ideas??

Thanks in advance

Leejohn · Oct 30, 2017

Curl the bucket all the way down. Shut off tractor and take the hose off the rod end of the cyl. Restart and try to curl bucket down, hold lever for a few sec. and if there is oil flow coming out of open fitting reseal the cyls.

JohnnyAirtime · Oct 30, 2017

Leejohn said:
Curl the bucket all the way down. Shut off tractor and take the hose off the rod end of the cyl. Restart and try to curl bucket down, hold lever for a few sec. and if there is oil flow coming out of open fitting reseal the cyls.

That test, is going to tell me if the cylinder(s) has an internal leak... allowing oil to bypass, internally?!

Leejohn · Oct 30, 2017

Yes It well.

JohnnyAirtime · Apr 20, 2020

Leejohn said:
Yes It well.

Thanks for the info....

I like to post updates, when a solution has been found. Nothing more frustrating to find a thread with no conclusion when researching a problem.

The lever assembly, wasn't pulling the valve out far enough. Too much slack/play in the fittings/orifices of the linkages. I replaced some linkage, used a bit bigger bolt (to take up some slack) and grinded a tad where the 'stop' hits the big metal plate (sorry... not super knowledgeable on terms).

Now... it works like a CHAMP! Curls with full power, and fast!!

... I also got the tractor running like a top. No more hard starts when cold, and no more sputtering under load. Thanks to a local gentleman (retired tractor mechanic), who does work as he can. Ken and his helper Manny, are great to utilize. Anyone in the San Diego County... need a GREAT mechanic, let me know!! He does it all. He's also who recently pulled my engine, and rebuilt it back to 100% (I spun a rear bearing - low on oil and digging up hill with the backhoe). Can't say enough about Ken!!