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Well, no big secret why the remotes couldn't pick up much. Anyway, I decided to replace it with a 15GPM. In order to give it the best life possible I decided to put an extender on it with an additional filter. Looking at the retainer, I'm not sure it will give all that much benefit.

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It seems that even though the filter area will double, there is still a bottleneck at this plate.

Thoughts?

While I'm asking: The suction tube o-ring was damaged, although it almost looked like installation damage. It's a -223. I have O, square, and X or quad on hand. Any reason to use other than the original O?

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i've never seen a filter base plate like that one. Does it appear to have been modified? Doesn't leave much area to draw oil through.

An o-ring should suffice for the pump suction tube, should have been one in the new pump. A quad ring wouldn't hurt though if you have one. How is the lip seal in the housing? If it doesn't grip the suction tube replacement would be worthwhile.

I'm not a big fan of the double filter setup, but extra filter capacity is not a bad thing.

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It almost looks like a plate has been soldered on to the filter base plate. I'll pull it out for a better look.

I meant the suction tube that draws from the sump. Since the PTO is out, I decided to unbolt the tube and check the O-ring; that's the one that was cut.

I was on the fence about the double filter and ordered it on a whim while I was ordering a MCV kit. The flow control valve has twice stuck wide open leaving no steering with the RPM was reduced after working. It required a good tap to get it back so there must be either some crud in it or the spool/bore needs to be polished a bit. Anyway, new springs and a general clean-up won't hurt.

Thanks, I appreciate your experience on these machines. The filter base just doesn't look quite right.

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I'd change that filter backing plate if it was me, I've never seen one like that before either. A regular o-ring should suffice for the suction tube. not that it matters but why did u go with the 15gpm pump instead of the 17?

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Ic. Just out of curiosity did you price the 17gpm pump vs the 15? Not trying to argue or say you made a poor choice just wondering if pricing is much different in your area as opposed to mine. Is your new pump aftermarket or CNH?

Thanks Craig

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It almost looks like a plate has been soldered on to the filter base plate. I'll pull it out for a better look.

I meant the suction tube that draws from the sump. Since the PTO is out, I decided to unbolt the tube and check the O-ring; that's the one that was cut.

I was on the fence about the double filter and ordered it on a whim while I was ordering a MCV kit. The flow control valve has twice stuck wide open leaving no steering with the RPM was reduced after working. It required a good tap to get it back so there must be either some crud in it or the spool/bore needs to be polished a bit. Anyway, new springs and a general clean-up won't hurt.

Thanks, I appreciate your experience on these machines. The filter base just doesn't look quite right.

I'm curious as to what was trying to be accomplished with that modification to the filter base plate. Sure doesn't leave much opening with a filter in place.

The flow divider valves do have a habit of sticking. I polish the valve with 400 while spinning the valve in a drill. (it will chuck into a 1/2" chuck) Then I have a tool I made to grip the inner bore and lap the spool to the bore. I leave some of the residue from polishing on the spool to help smooth the bore.

Jim N.

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I didn't get back to the filter today as I wanted to get into the MCV. I have had no reason to suspect the pump as I have good steering as low as the engine will idle, even with hot oil. I was, however, concerned with the sticking flow control.

Other than being somewhat hard to remove, I found nothing but some sludge and little scoring on the flow spool. I'll polish it as you suggest.

The pressure regulating valve was another story. It was a little difficult to remove and the problem became evident once it started to move. Some aluminum shavings told the story that the MCV pump had begun to fail.

I should have time to get that filter base retainer out tomorrow. I really want to get a look at it up close.

As for using a 15GPM pump: I figured that was a 25% increase over the original pump, I have a loader, so I won't be putting one on this machine, and the 15 was midway priced between a 12 and a 17. I guess I just couldn't find a reason to put a 17 on it.

Here's the partially removed pressure regulating valve complete with aluminum shavings from the MCV pump:

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Ic. Just out of curiosity did you price the 17gpm pump vs the 15? Not trying to argue or say you made a poor choice just wondering if pricing is much different in your area as opposed to mine. Is your new pump aftermarket or CNH?

Thanks Craig

Craig,

I figured that a 15GPM was a 25% increase over the original pump, I have a loader, so I won't be putting one on this machine, and the 15 was midway priced between a 12 and a 17. I guess I just couldn't find a reason to put a 17 on it.

It's an aftermarket pump.

Jim

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What series tractor is this on ?

786

Ok this is a 1 pump tractor then ? reason i ask the 856's etc have 2 pumps one is called the hitch pump right in front of the left rear axle

Two pumps - one MCV that powers the steering, clutch, brakes, TA, and lubes everything, and the hitch pump that runs the 3 point and remotes.

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What series tractor is this on ?

786

Ok this is a 1 pump tractor then ? reason i ask the 856's etc have 2 pumps one is called the hitch pump right in front of the left rear axle

Two pumps - one MCV that powers the steering, clutch, brakes, TA, and lubes everything, and the hitch pump that runs the 3 point and remotes.

OK thats what i though, I have seen people put Magnets inside of the housing were the filter is

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Ic. Just out of curiosity did you price the 17gpm pump vs the 15? Not trying to argue or say you made a poor choice just wondering if pricing is much different in your area as opposed to mine. Is your new pump aftermarket or CNH?

Thanks Craig

Craig,

I figured that a 15GPM was a 25% increase over the original pump, I have a loader, so I won't be putting one on this machine, and the 15 was midway priced between a 12 and a 17. I guess I just couldn't find a reason to put a 17 on it.

It's an aftermarket pump.

Jim

Ic. where i get them they r the same price, so i wondered if that was what helped u make your decision.

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I'm curious as to what was trying to be accomplished with that modification to the filter base plate. Sure doesn't leave much opening with a filter in place.

Jim N.

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Here it is on the bench. There is a plate spot welded in place and sealed with solder. Could it be some sort of service bulletin? If it's a mod, I am at a loss as to why.

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I'm curious as to what was trying to be accomplished with that modification to the filter base plate. Sure doesn't leave much opening with a filter in place.

Jim N.

post-43731-129200008409_thumb.jpg

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Here it is on the bench. There is a plate spot welded in place and sealed with solder. Could it be some sort of service bulletin? If it's a mod, I am at a loss as to why.

The only change made to that part was for the closed center systems and it looked nothing like that.

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It doesn't look like a backyard mod. The fact that it's spot welded and the metal is the same gauge and has the same appearance kind of rules that out.

I can see a plausible reason for it to be constructed this way. It keeps the MCV pump inlet supplied with oil after a filter change. The inlet tube cannot drain out when the filter is removed.

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Having a filter in the suction side of a hydraulic system is not ideal. It's almost asking for cavitation damage. Gear pumps are usually pretty hardy compared to piston pumps but I think a return filter system with an inlet screen to keep the nuts and bolts out is better. That's the way most aircraft are set up. That would be pretty much impossible to do here since the last thing the oil does is lube bearings and gears and then drain into the case. A full-flow pressure filter like the engine system could have worked.

With all the vendors selling pumps for this series machine it would seem that it's at least a somewhat troublesome area.

I'm going to open up the area in the base plate somewhat without uncovering the MCV inlet. It's entirely possible that the failed pumps began their trip to the scrap heap with some cavitation damage. I have seen aircraft pumps that were severely damaged by cavitation because the reservoirs weren't pressurized on start-up. I'd like this to be the last time I ever do anything to this hydraulic system!

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The big problem with a hydraulic return filter on a tractor is that, unlike an airplane, the oil for the hydraulic system is shared with the transmission. Any debris from the transmission would have to go through the pumps and hydraulic system before it would get to the filter.

The biggest problem with cavitation on the MCV pump is due to air being drawn in past the seal between the center section and rear frame. That seal and the one between the pickup tube and the filter cavity are the two places where they are above the normal oil level.

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Well, here it is, before and after my compromise mod.

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With a very precise tool* I have calculated the cross sectional area is now in excess of the combined area of the suction pipes of the two pumps. I am happy, I hope the pumps are.:lol:

*Mark I calibrated eyeball

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