Hello, I have a very old Massey 35 tractor with a Shawnee bucket and backhoe. I don't use it much but now I am putting in a field at the cottage and want to use it to do so. I'm finding that the hydraulic power just isn't what it used to be, and once the hydraulic oil gets hot, the power really diminishes. I was told to check the oil with all cylinders retracted, so I did, with the backhoe up in the air to retract the boom cylinder. Level is fine, but after running awhile it's real week. Even just lifting the boom with the arm extended is difficult for it, so lifting a load with things extended is out of the question the way it is. I was trying to pull some stumps ..but it would't budge them.
Does this sound like the pump needs reconditioning? It is a front mounted unit. A Webster. Might be touch to get parts for. Any advice would be appreciated.
Thanks!

When was the last time you changed the Hydraulic Oil?

Changing includes draining the tank, draining all the lines and emptying all the actuators.

OR

Draining the tank, Refilling it, cycling all actuators at least 10 times, drain the tank, Refill it,REPEAT ABOVE until drained oil clears up.

Not CHEAP or EASY but NECESSARY!!!

Hi Bud,
Thanks for the reply. I've never drained to the extent you describe. I have drained with cylinders retracted as described in my first post, but have not drained the lines and refilled and cycled etc.
When the tractor has been sitting awhile the oil looks fine, but after it gets hot the oil looks somewhat foamy.
Today I took the pump to a farm equip dealer that sells a lot of pumps. We took the cover off and saw very slight scoring where the sides of one of the gears seems to have rubbed the case, but it is more 'visible' than 'feelable'. There is virtually no gap between the gears and the housing.
The interesting thing is that the fellow who looked at it said it is set up backwards. The return oil is coming in the small port and the pumped oil is leaving through the large one, which is adapted down to the proper hose size.
He thinks it was done to match the rotation of the engine. There are two little 'passages on the inside cheek of the housing that he says are to allow surplus oil that the gears can't handle ..to go back to the inlet area. Currently those are on the outlet side which he says is dead wrong. I'll attach a photo showing the pump on the front of the tractor. You can see the difference in the pipe sizes on the return and pressure sides if you zoom in a bit.

How many gallons of fluid do you think I'll need? I think I like your idea of draining the cylinders and lines better than the 'cycling' system ...which sounds like it could take a while and a lot of oil, and possibly not be as positive a solution as the first one.

I'm thinking I could put the oil back in that I took out yesterday. I had put it in a clean pail, through a filter as wanted to see if there were any filterable contaminants in it ...and there weren't. When cool the oil looks fine, only after running and getting good and warm does it get foamy looking. I only got about 4 gal out, if that.
Anyway if I'm interpreting you correctly, I'd have to
1) put the oil back in so I can get the backhoe down
2) lay down backhoe down fully extended or position it so I could get at the fittings and if necessary, chain it in place
3) lay the loader down at normal 'at rest position' with cylinders retracted
4) drain the resevoir
5) drain all hoses and drain the side of each cylinder that would have oil in it at the position it is in??
6) refill resevoir
7) cycle everything a bunch
8) top up resevoir again to replace what went in the cylinders

Any precations re air locks or anything to avoid them?

Any correction to above or illustration would be helpful.

Bud, I'm also thinking of replacing the pump. I can get a new one that will rotate in the right direction without reversing the ports, for $270.00. It's an Italian one, a little shorter top to bottom but deeper (longer vanes). The pump on there now is 1.94 cu in and the new one is 1.93. The tractor doesn't owe me anything and at this point I don't mind doing that ...if it corrects what might be a poor setup anyway.

When I drained the resevoir yesterday I only got about 4 gallons out. Right now the backhoe is fully extended, backhoe bucket extended, boom retracted (so backhoe bucket is as high as possible), and loader is down with loader bucket flat (cylinder retracted). How much more fluid do you think might still in there?

Hope you don't mind all these questions. I don't have much hydraulic experience.

Thanks,
Jay

Any precations re air locks or anything to avoid them?

You will have to cycle the cylinders to refill them and purge the air and they may be erratic due the airs compressibility. A pure safe way is to disconnect the cylinders from their load and operate them in the air.

ANother way without disconnecting them is to crack the fitting at the ports of the fully retracted cylinders and remove the lines from the opposite end of the cylinders. Slowly shift the valve to send oil to the cylinder and purge the air in the lines up to the cylinder. Then tighten the fittings and slowly extend the cylinder, forcing the air in the opposite end to atmosphere. Reconnect the opposite port and cycle the cylinders until the small amount of air in the second end is disipated.

I notice from your picture you appear to be using PRESSURE HOSE for the Suction Line. That is a big NO-NO since Pressure Hose has a liner that is not really fused to the exterior portion that is designed to take pressure. In Vacuum service the inner liner can collapse and starve the pump. That scenario was even exagerated in your case with the reduced size inlet. Hard pipe all the way or use a section of SUCTION HOSE for the pump inlet to give some flexibility.

Pump running backwards???? WOW. I believe anything any more since Fluid Power is so little understood.

Hi again Bud,
Actually the suction line is the fat one, hose clamped to the pipe going into the small port thereby = backwards. The pressure is coming off the large port and is reduced down to the pressure line diameter. That's how it was when I bought it about 12 years ago and it actually worked great for years. I probably don't know how good it would work if it was all done properly!
Thanks for the advice! I also stopped by tonight at a tractor rebuilder in Lockport, Manitoba, JJ Riverside. He does total teardowns and rebuilds them, and sells them with regular warranties. He's done many old 35's like mine. I once saw him doing 5 at once. All were at the same stage when I saw them ..totally stripped, on blocks and with their 3 point hitches all disassembled for inspection and repair as needed. When they leave his shop they are virtually new tractors. Even the body work is flawless and they all get new rubber, lights, instruments, etc.
Tonight he had a John Deer Diesel in there with a Shawnee loader exactly the same as mine (no backhoe), so it was easy to talk about the hydraulics as even the valve assembly for it matched mine
He told me the way he evacuates the fluid is to disconnect all the hoses from all the cylinders uncouple the rams, and cycle them manually in both directions to get all the oil out. Then blow out all the lines and valves using compressed air. He said it's a 2 hour plus, messy job but in his experience completely purges the system. Refilling and purging air is the same as what you described. Sounds like a daunting excercise but he claims he does all his that way. He also replaces any hoses that are even slightly suspect and when done has confidence to warranty the system.
I'm going to buy the new pump and take it with me, but I'll do the fluid change first and try the old pump again. If there's still a problem I'll put the new one on. If there's still a problem after that ....you won't hear from me. Nobody will ..I'll be gone!
All the best!
Jay

you mentioned foamy oil, which might indicate a suction air leak, or cavitation due to the undersized suction port.

also, does the new pump have the presure rating? you mentioned gear pump now, vane pump as the replacement.

any other suction restrictions, strainer plugged, etc?

bud has sharp eyes on the hose, I didn't notice that from the picture.

Kevin;

My sharp eyes didn't sse the Hose Clamps. James says those are hose clamps are holding Suction Hose on the pipe. SPoke too quick.

Still not the best and could be sucking air since inlet flow velocity is probably quite high.

Could be sucking air at the shaft seal also.

"you mentioned foamy oil, which might indicate a suction air leak, or cavitation due to the undersized suction port."

Good idea !

Hi guys,
Here's an update. I installed a new pump and at the same time changed all the oil. I followed the crack and bleed method to get the air out.
Had blown out the big line between the backhoe valves and the resivoir and with 3 of us doing different things ..forgot to reconnect it before starting the tractor. My wife has put some new topsoil and seed down in an attempt to restore the grass there. Oops.

I got 'all season' hydraulic oil, thinking that would allow me to use the machine in winter for snow clearing at the cottage.

Lots of power now. I made great progress on the septic field. I dug and moved boulders that must weigh as much as a small car! Tree stumps came out like they dearly wanted to.

In the cool early morning everything works fine, but as the day gets hot (80F+) the hydraulics start to squeal, really squeal.
I suspect I should have used a regular summerweight hydraulic oil. I spoke to the vendor about it and can drain the oil and return it and get a single weight.
Have you guys had any experience with the 'all season' oils?

sounds like you may have more than one issue here but the obvious one to me is that the brand of oil you use cannot release air by itself. with a quality engineered product you can have the same use from your machine when it is hot as when it is cold.this is my first time on here so i'm not sure if i can tell you who sells it without getting the site boss mad.personally, i have seen an excavator that was bursting hoses constantly and replacing o-rings every week until the right brand of oil went in. all problems stopped and the machine has more pressure and less temp.. cycle times are faster and the pump doesn't whine and there is no need to wait for the oil to warm up so you can begin using the machine.

Try changing any seals on the relief and readjust it to see if it helps your squeal...