1978 Allis chalmers 7000

This tractor is up for auction tomorrow. I went to look at it today. It started fine. Fuel pump was leaking a fair amount while running. My main concern is it wouldn't go into gear. Im not real familiar with this series of allis but the gear selector nearest the window had I, II, III wouldn't move out II. The other lever moved fine and twisted, not sure what gear is what on that selector but tried all of them. Still the tractor didn't try to move at all not even a shutter. It was low on oil, but still on dipstick. The clutch pedal felt real soft. The worker at the auction place tried to move but couldn't either. He said that they have moved it around the yard and drove it through the ring last month but it was no sale. Any input is greatly appreciated.

That would be the powershift lever.  If it is hung between ranges, it will not pressurize any clutch packs.  The oil level you checked, if it was on a dip stick, was the rear end oil level, which has nothing to do with the hydraulic system and the power shift clutches.  The oil level you need to check is done by sight glasses behind the battery(s).  You will see a fill tube and sight glasses below that.  You want the first glass filled and the top glass empty/slightly filled.  Be careful working on the power shift linkage, as if it is in gear and you suddenly shift the valve body into a gear, it will take off and run you over.  The clutch pedal will be soft for most of the travel if it is working correctly.  The first 7/8 of travel or so should just feel like you are pushing against a spring, then in the last couple of inches, it should get noticeably stiffer as it engages the transmission brake.  I really wouldn't pay a lot for that tractor without it moving, as those power shift clutch packs are pricey to work on, especially if you buy all new parts (and you can only get new parts for the 2nd and 3rd range clutch packs on that tractor as far as discs go).  It also may have just lost prime, but still, the I, II, III shift lever should move.  It is a cable that moves, so check that cable to make sure it's not binding up.  If you look on the tractor's right side, you will see an aluminum valve body, and that is where you will find the actuating lever that this control lever operates.  It is at the lower part of the valve body and you will also see a cam type lever that will push back on this lever when it is engaged in the forward two positions (this is the powershift kick down lever that is connected to the clutch pedal also, so you will feel that extra resistance in the pedal as you depress it if the power shift is not in I range and everything is in decent adjustment).  It is really hard to know exactly what is happening without seeing the tractor.  Does the power steering work?  If so, chances are the problem is not with the hydraulic pump, but something in the shift linkage, the clutch pack, or the valve body.  Doesn't really take much out of the equation other than a bad hydraulic pump or a hydraulic system that is low on oil and/or lost prime.

Hurst

Doc asked the question that would've simplified my response a lot and I failed to think of until the end of typing mine... about par for the course for me: overthink the problem and then realize there's an underlying question that should be asked before bringing up everything else I said...

Hurst

Ill see if the power steering works. I forgot to mention the tranny pressure light was on all the time

There's pics on the cook tractor website. Ill let you know what it brings.

If the tranny pressure light is on, then you have a hydraulic issue that needs to be solved more than likely.  If the power steering works, then the problem is not the hydraulic pump, but somewhere in the power shift valving or clutch pack.  The tranny pressure light could also be a wire that has rubbed through and grounded out on the chassis of the tractor, but the chances of that and the symptoms you described are not very high.

Pump lost prime would be the first thing I would try.  Just loosen up the line that goes to the hydraulic cooler and the one that goes to the power steering a couple turns, rev the tractor up to like 1500 rpms, and then go in the cab and work the steering wheel back and forth.  When it primes, you will know it because stuff will begin working and the fitting(s) you loosened will begin to leak.  Tighten them back up and you should be good to test the powershift.  I would make sure you get the shift linkage worked out.  The other clutch packs are not designed to inch...  Also, check the hydraulic fluid level at the sight glass before doing anything.  If the level is low, you could eat the pump up if there's no fluid to pull up and through it.

Hurst

They had a 8030 down there? Was it a 2wd or FWA? It wasnt on the sale bill

Quick question: Where is the hydraulic filter located on the 7000

There is a plate below the batteries and below fill cap on the right side of tractor that covers the cartridge filter. Six nuts hold the plate on. Remove the nuts and the filter is held onto the plate by spring clips. If your hydraulics and steering are coming and going check hydraulic fluid level. Two site glasses behind batteries. Try fluid level first, see if that is your issue.

Can you run your basic hydro oil in the allis? I know some situations it may gum things up.

Ben (MI) wrote: Knight, In a 7000 series, use a tractor hydraulic fluid listed as Allis Power Fluid 821 compatible. There is some cheap stuff out there I wouldn't even buy to start a brush fire with.

I would use a premium universal hydraulic fluid that specs the AC 821xl fluid. Some of the cheaper line specifics it meets this criterion. As posted above, don't use the cheap stuff!! The extra 10 or 15 dollars a pail is peace of mind and money saved in longevity of your hydraulic components   

A gauge will tell you part of the story, better than nothing. Pressure reading depends somewhat on the tractor, but should be 2000 - 2400 PSI or so. A better check is a flow meter and pressure gauge setup. Find out the rated flow of the tractor and make sure it outputs that. Then keep it running until the tractor and the oil are good and warmed up, and the pressure should not drop more than 15 -20%.

Cottonpatch, do you know the part number for this cartridge you refer to under the plate?

Edited by jazzsuds - 05 Jan 2018 at 8:54am

Hydraulic filter for 7000. Agco part #70260906.