504 pump failing?

[GrizzyDan]

I believe my hydraulic pump is on it's way out, the last owner said it takes a little while to warm up, and I've definitely noticed this. I've put 5 gallons of R&O hydraulic fluid into the tank that doubles as the left loader arm pillar but I'm not sure if I should top it off or not, by the sound it makes when filling it it is now very close to the top, yet it has not solved the issue.

All of the hydraulics act like there is air in the system for 10-15 minutes after firing it up, lifting the loader arms, curling the bucket, and turning the steering wheel during this time both make the pump create quite a bit of noise and the hydraulics work jerky and sporadic (timed with the noise) until the system "warms up" and it will run fine for the rest of the day.

Does this sound like air in the system? or would it be cavitation? Do you guys think my pump is making it's last death wails? It has been a few years since I took a hydraulic class but they only explained cavitation as "Turning your steering wheel in your car all the way to one side until it squeels" It kinda sounds like that.. but so much different/worse..

Thanks

Dan

 

[GrizzyDan]

Oh, this also seems to limit what I can lift with the loader, I slowly (1st gear, 900-1200 rpm) dig into a pile of gravel and it won't lift out of it with half a bucket full.. The pump screams and I have to tilt the bucket down, lift the loader, then try to curl the bucket up out of the pile to even get half a bucket load..

The more I think about this, and typing it out here, the more concrete it becomes for me. A pressure relief valve wouldn't make noise like this correct?

Also if anyone has a good source to find replacement parts for old internationals I'd be much appreciative.. it's a 1967 IH 504 4 cyl diesel and I don't believe it's a farmall.

Thanks

Dan

 

[cowski]

we had one of them when i was a kid.i need a little more info to help.does the loader have its own separate pump and relief valve. if it does take the valve out and clean it. some of the relief valves are adjustable.you really need a gauge to set it.a few pictures would help.

 

[DJ54]

Being the oil reservoir is on the loader, I'm guessing it has a front mount pump. Even if not, there are 3 things I would check.

Hyd. filter. If front mount, there should be some type of filter canister, possibly near the controls, or along side the frame, before getting back to the conntrols. If not front mount pump, the filter(s) are in the belly of the tractor.

Vent on the oil reservoir. Either built into the filler cap, or a small mesh filled, mushroom type. Could cause a vacuum in the reservoir, and not let it feed oil properly. Could cause the pump to suck air, if the supply side is just held on with hose clamps. And eventually, possibly cause the supply line to collapse internally, restricting flow.

And as mentioned, the bypass valve.

If the hyd. system has never been completely flushed, there could be gunk in the system, and collected in the filter. Moisture from condensation, etc., possibly congeals in there, and makes for a slow start, until things get warmed up, and pulls it through the system.

Parts should be fairly easy to find. Case/IH should still carry a full line of replacement parts. Many aftermarket ones out there too. If it's major casting parts. etc. you can do a parts search here: Used Tractors For Sale at TractorHouse.com: John Deere Tractors, used farm tractors and farm equipment, tractors for sale, Case IH, New Holland, Agco, Kubota, and look for salvaged tractors.

 

[GrizzyDan]

I am more confused than ever now :laughing: The loader runs off what I assume is the stock hydraulic pump which runs the steering and rear hydraulics. A diverter valve was placed on what would be the passenger side, and from there a flexible hydraulic hose runs over the transmission infront of the seat to the left side where the twin loader valves are. From there 4 lines run out to lift, lower, and curl the loader, and the return line from the valves dump right into the loader pillar which they are mounted to, this is not seen.

There is a hydraulic hose that connect the loader pillar/tank to the tank under the seat to cycle the fluid from the extra storage. There is no vent that I am aware of, no external filter, the highest point on the tractor under the seat has a pipe plug blocking it off.

I left the fill cap off the loader pillar once after filling it and fired up the tractor to see if it ran better.. yet proceded to geyser about a gallon of fluid when I dropped the loader arms :ashamed: I assumed at the time that it meant the system was a "pressurized" system, but realize now that it is the return side--the "low" side of the system. I am currently using the fill on the loader pillar to add fluid to the system, I have not located a filler for the hyd system tractor side (doesn't just jump out at you like the radiator or diesel tank lol :laughing

I will search again for a vent, built in oil filter, and pressure relief valve are located, yet it's fairly safe to assume that they are all in stock locations at this point.(I am on a limited budget at this point and haven't been able to pick up a manual) There is no adjustment to the loader valves externally.

These are the best pictures i have currently. Tomorrow I will take some closer shots of the pump and see if I can make heads or tails of it (and see if anyone can tell me if it's not stock.. etc.)

Best I have of the valves..

More tomorrow.

 

[cowski]

like dj54 ,when you said that it had a loader tank i thought it was a separate pump. since it uses the main pump clean the filter and the filter relief valve.like dj54 said it is in the belly.now it sounds like you have 2 problems.one is a valve is letting the hydraulic fluid drain down and letting air into the system.this will cause the jerking until it warms up and gets the air out.ask dj54 if there is a check valve on the loader? 2 weak hydraulic pressure.this could be caused by plugged filter ,bad or dirty relief valve,relief valve out of adjustment or a bad pump.after you clean the filter and the filter relief valve.the loader relief valve appears to be in front of the handles on the loader.while cleaning it check the spring and valve for breakage or damage or bad o ring .some relief valves are adjustable by adding shims to the spring or by a bolt adjustment.it can also have another relief valve. does it have power steering?