Case 990 from 1975, 3-point rises up on its own

Rancher Pete · May 29, 2012

I have a very nice Case 990 (David Brown style) tractor that I use almost every day for one thing or another. Lately the three-point arms lift up on their own. If I push my three-point control lever forward the arms will lower but then when I let go of the control lever the arms raise back up to the top all by themselves. The control lever actually feels like it is spring loaded so, as I stated, when I let go of the lever it seems to spring back to its middle position and then I see the 3-point arms raise. If I hold the lever in any given position the arms will stay put for the most part. I do not know what could be causing this and I do not know where to locate any valves that may be plugged as I have read about others doing on the forum. Any ideas, guys?

RGMartin · May 29, 2012

(quoted from post at 19:31:34 05/29/12) The control lever actually feels like it is spring loaded

It should feel like it is spring loaded, as it is spring loaded.

The friction disc on the base of your 3 point control lever needs adjusted. It takes two 3/4" wrenches to do the job. Look where your right heel would rest when you are sitting on the tractor, on the housing the parking brake handle goes through. Loosen the jamb nut, then snug up the bottom nut till the handle has as much resistance as you would like. Then lock down the jam nut. The plastic cap doesn't need to come off. Shouldn't take more than 10 minutes.

Rancher Pete · May 29, 2012

Thanks so much for your thoughtful reply. I saw those two nuts and was going to give them a turn in the morning. After all of the time I have spent on this tractor it never occurred to me that the lever is actually spring loaded. I suppose that if the nuts are adjusted properly one would not notice the spring loading but now that the lever (or nuts) have loosened the spring tension is more evident. I thought that the 'springiness' I was feeling was hydraulic pressure and that if I adjusted the nuts to keep the lever in place (not caving in to the pressure) I might build up pressure in an undesirable way and then pay for it in some other manner. I will get into this in the morning and see how it goes. By the way: do you know where those valves are located that I have heard so many people talk about... the ones that they say they push down on with a little wooden dowel to remove and clean, and they have a ball bearing inside? I's still like to check those. Thanks again for your help. I'll let you know how it turns out. Pete

RGMartin · May 30, 2012

(quoted from post at 21:13:48 05/29/12) By the way: do you know where those valves are located that I have heard so many people talk about... the ones that they say they push down on with a little wooden dowel to remove and clean, and they have a ball bearing inside? I's still like to check those.

"Hold" and "Bypass" valves, I know them well. If they are working, leave them alone. Way to easy to introduce dirt into them, and make them not work.

If you want to do preventative maintenance on your hydraulics, change the oil and suction filter.

Rancher Pete · May 30, 2012

I took your advice and stayed away from the valves. I tightened that 3/4" nut and jam nut so that there is just a bit of friction on the lever and all is well. It holds perfectly. Thanks again for your help. You saved me from what could have turned into a real headache.

Have a great week ahead.

Pete

RGMartin · May 30, 2012

You are very welcome.

If you haven't ever changed your hydraulic filter you should probably look into doing it. It will save you a bunch of hydraulic headaches down the road.

Rancher Pete · Jun 11, 2012

Dear RGMArtin: A few weeks back you were good enough to help me with an issue I was having with my 1975 Case/David Brown 990. Your simple advice solved my problem and my tractor is working well for me. One of my guys (who helps me cut, rake, bail and haul my hay) has a 1985 Case - International Model 1494. It is a four wheel drive tractor and he just bought it recently. His tractor (like mine) grinds when we try to engage the PTO with the engine running. Perhaps since they are different tractors there may be different reasons for why this is happening. If we shut the tractor(s) down all together, engage the PTO and then restart the tractor the PTO hold and functions just fine but it would of course be nice to engage the PTO while the tractor is running for obvious reasons. Would you by any chance happen to know what might cause this (on one or both of these tractors) or, if not, be able to direct us to where we may find some answers? Any info would be more than we have to work with at the moment. Many thanks for anything you can offer up and thanks again for your help earlier.

Best Regards,
Peter Johnston
Durango Colorado

RGMartin · Jun 11, 2012

Are you using the clutch pedal on your 990 when you try to engage the PTO?

The 1494 is a D Brown too, very similar construction, except it has a hand clutch you have to use to engage the PTO. It is located next to the parking brake. They can often be found with a bad throw out bearing on the PTO clutch as someone left the lever in the up position.

Rancher Pete · Jun 11, 2012

With my 990 I use the foot clutch in order to attempt to engage the PTO. I think I heard somewhere that when you depress the clutch you are first activating the main clutch for the transmission, and then further depression of the clutch then goes to activation the secondary clutch for the PTO toward the bottom of the pedal movement. Maybe an adjustment of the travel for the foot clutch might allow the PTO clutch to be depressed a little more so as to allow it to pop in rather that grind. I will have to try that.

With the 1494, my friend does attempt to use the hand clutch you mention but it does not allow him to engage without feeling that he is going to grind the gears to death. It may very well be the the throw-out bearing, as you suggest, or perhaps he can try to adjust the linkage on that lever so that it will have a little more "pull". We'll dig into it a little more. Thanks again.

Pete

RGMartin · Jun 12, 2012

Linkage is adjustable on both. One person operating the clutch while another watches what is going on through the inspection hole under the tractor will give you an idea of what is going on(NOT when the engine is running, chock the wheels, safety first).

Make sure the bearing isn't against the pressure plate all the time, or the bearing will fail.

Not a good idea to force the 1494, as the shift fork and rod it rides on simply aren't that strong and you will brake something. The 990 set up is more robust, but you will chew up the gears if you force it.

Case 990 from 1975, 3-point rises up on its own

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