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Another MCV pump or?


New Englander

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About 175 hours ago I replaced both pumps, cleaned out the main case and installed an MCV kit. All on a 786.

After that work I had effortless steering at 500RPM. It's been taking higher and higher RPM to get steering and turn the lube light out. Now it takes about 1400 to turn lube light out and about 1500 before any steering assist is noticed.

I thought the flow control valve might have stuck as it's happened before on this machine. It was not stuck.

Any thoughts before I order another pump?

Thanks,

Jim

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Relief valve looks OK. Pump doesn't look too bad but I'll replace it.

Hy-Capacity has a 13GPM pump that I'd like to try. Who's got the best prices for Hy-Capacity? Are the pumps sold by Abilene Machine Hy-Capacity pumps?

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bought my pump from case ih dealer (hy cap) for $335 i think , dont 'know about abilene's.

be shure to check that o ring that jim griest spoke of, it was bad on mine . i had no steering at all

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Supercharge line is on.

Are you talking about the O rings in the MCV valve assembly between the case and the MCV and between the valve body and steel plates? If so, they were all perfect.

By sump check valve do you mean the little plastic steering check valve? That seems to be in good shape as well.

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Yes those orings , its hard to know on the sump check without putting a dowel in there ,

Does your aux hyd work ok? Wonder if the oring on the hitch pump could be blown? Or did deal on hitch pump in by filter get damaged in the change? If the hitch pump is giving trouble it could put air in the supercharge line?

But you could still have a bad pump too? Sorry to be so vague but lots for you to look at

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Hitch pump is working normally, filters were normal, no junk on the bypass screen to indicate they were clogging - it has the dual filter conversion so it's hard to imagine they would totally clog without a catastrophic failure.

It really was acting like a stuck flow control valve but it's free.

I'll report after the new pump. I guess they're all imports now but I really want to try the 13GPM in place of a 12.

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B.t.w. was it a hycap pump? I see the are same price id bet theyd let you trade up , if its a&i -good luck

I can't remember where I got the pump - on line for sure as the nearest dealer is several hours away. It well may have been A&I.

The trashed pump I pulled out before had brass or bronze wear plates, this one has but one aluminum plate on the drive side. It all looks OK except for a slightly chewed up rubber seal on the aluminum wear plate. The rubber looks like it helps to direct lube oil to the drive end bearing.

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Dont rule out a blown gasket inside the MCV to cause problems too. Dads 806 got to where the lube light would come on when you stepped on the brakes. The pump wasnt that old and I had gone trough the valve when we replaced it too. I pulled the MCV thinking we would need a pump and decided to take the valve all apart and found the gasket between the valve body and the steel plate blown in one of the passages. It never lost steering at all but the light would come on. Went ahead and put a pump on it while we were there anyway.

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Dont rule out a blown gasket inside the MCV to cause problems too. Dads 806 got to where the lube light would come on when you stepped on the brakes. The pump wasnt that old and I had gone trough the valve when we replaced it too. I pulled the MCV thinking we would need a pump and decided to take the valve all apart and found the gasket between the valve body and the steel plate blown in one of the passages. It never lost steering at all but the light would come on. Went ahead and put a pump on it while we were there anyway.

All of those gaskets and o rings were new and intact. I guess we'll just have to see what a new pump does for it.

It'll take a couple of days for me to get one.

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New pump fixed it. Good steering as low as the engine will idle.

I'm somewhat embarrassed to say that I never removed the driven gear from the bad pump. I had pulled the drive gear as it came away with the cover. Both ends of the drive gear, pump housing, and bushings in the cover were near pristine. It was only when I was ready to toss the pump did I pull the driven gear out and found the shaft was galled badly. Frankly I'm a little shocked to find that much damage only on one of 4 bearing surfaces, especially on the one that doesn't have the load of the gear drive.

Never again will I buy an inexpensive or economy pump.

Thanks for everyone's suggestions.

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I was putting a rear pump in a hydro 1066 a few years ago and I tightened the nut with a small impact wrench like I have done a lot of times. The pump locked up I took it apart to see what was wrong and it looked like it pumped gravel in the inside. That was the last off brand pump I have put in. I put a CNh hydraulic pump in our 856 today 620 dollars but worth it an off brand was 450 plus shipping.

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