7080 Hyd. Problem

The flow divider is stuck, and is diverting oil from the steering system and sending oil to the brakes. The spool needs to be removed, and polished.

Is it a FWA or two wheel drive?                       MACK

my 7080 does the same

That's what I thought. Each gets its flow from a different pump, so I was wondering why both wouldn't be working. 

I'll call the mechanic tomorrow and see what he's done, and I might suggest that. I hate to be one of "those guys" asking questions all the time and telling a mechanic how to do his job, but it's been in the shop over 5 months and no culprit has been found. I need to be getting ground worked, it will be cotton planting time in a month and a half, and I'm tractor-less.

Edited by CrestonM - 23 Mar 2022 at 9:20pm

If its been in the shop for 5 months and no problem has been found the guy obviously isnt going to fix it. He should have said its beyond my capacity and given it back.
Ask any question you want its your machine.

Edited by JPG AUSTRALIA - 24 Mar 2022 at 7:07am

Mack, that is correct. I put Agco filters in, and even pulled it back out to double check the screen was present.

Yes, that is correct. When I got the tractor, it didn’t have the plate with the spring. Ordered a new one from Agco.

A couple times, the steering would work fine. But just for a few seconds, then go back to requiring two hands. But very occasionally it would work and you could turn it with one finger.

Edited by CrestonM - 24 Mar 2022 at 12:55pm

If that is the problem (and it could be) the operator should hear the pumps cavitating, because they are starving for oil. This would also have an effect on the main implement pump, but again the hydraulic system would be making noises.

That  "hammer tapping"phrase brought back memories of the D15 !! I hope all gets sorted out for you sooner-than-later Creston 

I have also found strap bent and found one on backwards.                MACK

It doesn't take a hydraulic tester (flow-rater) to remove the steering pump priority valve and make sure it isn't stuck in its bore. If it's stuck and removed and polished and the steering starts to work like it should, there's no need for a tester.

I don't personally recall ever using a flow rater on a 7000 series. Won't say that I haven't, just don't remember. Gauges will tell you most everything you need to know. Sure sounds like a flow restriction problem to the pumps, especially the left hand filter. You seem to have two problems with two separate circuits that the common factor is that left hand filter and getting oil through it. Always possible to have two separate pump problems, but somewhat doubtful. I should also add,be sure that the sight glasses are full. They can get a brown film on them and appear to be full of oil when they are not.

Edited by Lynn Marshall - 29 Mar 2022 at 8:03am

I have an update…the mechanic called me, he hooked his flow rater up to the steering circuit, and once the oil got warmed up, it flowed about 5 gallons or something to that effect. However, when a load was applied to the steering wheel, it wouldn’t flow at all, and it built less than 1000 psi. What he’s thinking, and what makes sense to me, is since the left hand filter was missing the screen when I got it, it wasn’t opening that door in the filter housing, starving the pump of oil, and what oil did go through there wasn’t filtered. I don’t know how well the previous owner cleaned his remote hydraulic tips when he plugged them in, I don’t know how long he ran it without that screen on the filter, but the assumption now is the gear pump  is probably junk.  And he said he couldn’t test the piston pump until the gear pump was replaced. A rebuilt gear pump was quoted at $3000, and a new aftermarket pump was quoted at $5000. I’m not sure what to do next, I know if I put this much money into the tractor I probably won’t get that back out of it, I would have a total of about $10,000 in the tractor.  I’m not sure whether I should try to find a cheaper used pump to put in, because I understand the gamble with that as well. Taking suggestions at this point.

Would a pump out of a 7020 work in this 1975 7080? There is a somewhat rough 7020 coming up at auction on Saturday, but the hydraulics seem to function as they should. I thought I might buy the tractor, take the pumps out of it, and sell or part out the rest. It has nearly new near rubber on the back, which I don’t need, but that might could help me recoup some of my cost.

Edited by CrestonM - 30 Mar 2022 at 9:26pm