I have a 1986 case w-20B wheel loader. The operator has been mentioning a noise coming from under the floorboards and it gets louder when cycling the bucket and boom. Does anyone know how much noise a pump should make? and is there any way to test and see if this pump is on its way out?? thanks!
Check the hyd oil level .Next change the hyd filter. If these are ok the noise is likely pump wear a pressure test should confirm that.
Check the air pressure regulator on top of the reservoir, it may have failed and not allowing the oil to pressurize the pump intake.
Both your replies so far are pretty right and I would like to add:- If the noise sounds like it is "pumping marbles",then the problem is cavitation or low oil level. Cavitation is too low (or negative) pressure at the pump inlet and can be caused by a) what BillG described if it has a pressurised tank, b) oil too high viscosity for the ambient temp, c) blocked strainer in the tank, d) suction hoses collapsing internally or sucking in. Sorry to disagree with 250c but the filter will have a bypass valve for when it is blocked and probably won't make a noise. Pump on the way out is possible but a pressure test will not identify this. Gear train noise or a noisy bearing in the pump drive gear train can also fit your description but something as simple as a loosely bracketed steel pipe could also be the cause. In Australia we use what we call the "Kodak" method..............wait and see what develops! Cheers, Maurie.
When you pull the filters, be sure and rinse them in some clean kerosene and see what metal comes out of them. If you have a good bit of metal debris, especially aluminum, could have a gear pump going south.
Thank you, willie59. I am new and a little nervous...............I should have added what you said-good point. Hope you have a happy outcome, zlssefi.
Welcome to the forum stondad. :usa
Here is what i have done so far. Last year before plowing i changed out the filters. I should have cut them open to check for metal but i didnt. It doesnt sound like cavitating, but as you mention it it does sound like a bearing noise. I will check to make sure the tank is being pressurized. I know there is a valve on the right as your looking at the front of the loader, inside the access panel. Ill check that to make sure their is air pressure being applied to the tank. If its a bearing going bad, would it be in the pump it self? or in the transmission where it drives the pump?
Don't really have to cut filters open to check them. Remove the filter, pour the contents in a clean drain pan. Then pour some Kero or Naptha in filter element, place your hand or a piece of plywood over the end and shake it. Pour that into your drain pan and see what rinses out.
Depending on the brand and type of pump, it may have ball or straight roller bearings, or bushes. If it is a crook bearing, I wouldn't like to guess where it is unless I saw the pump and identified it. The problem is that they may have come out with say a Vickers vane pump which has a cam ring that will make a noise if it has steps worn in it, but it could have been changed-out for say a Tyrone gear pump which has only bushes-so no one will know unless they actually see it. You need help now from someone who is on the spot with the machine, or who knows the W-20B and their transmission well enough to take an educated guess for you with maybe a common fault in the pump drive. Sorry I can't help more but it's many years since I sat on one or put a spanner on one.
Update.....Here is what has taken place. I found a brand new permco pump for a little over 700 bucks brand new. I purchased that, installed it as well as remove the transmission pump to check for worn bearings,gears etc. Resealed the transmission pump and re installed and installed the hydraulic pump. I topped off all fluids and fired the machine to check for leaks. The noise is now about half of what it was before. Sounds better, hydraulics have tons of power etc. Now my question is this: has anyone had problems with the suction tube in the transmission falling off, getting pin holes etc? the transmission is a tt2221-1 powershift allison. Im wondering if i had a combination problem of worn hydraulic pump and slight cavitation of transmission pump making one big noise. Another question i had was is there someone on this forum who has run w-20B machines for many hours who could tell me if its normal to have some noise under the floorboard that fluctuates with the throttle? i really havent run the machine enough to know if its normal or not. I look forward to some more replies!
Sounds like you are doing a good job. You must check and probably reset the main pressure relief valve after fitting the new hydraulic pump otherwise the "tons of power" you have at the moment might be a bit too much ! From my time operating Case machines fitted up with forks many years ago I remember them as a pretty growly machine but they were far from new either. I will try to find the name of our friend on the Forum who is an expert on Allison loader transmissions so you can ask him. All I can say is that if you have a problem with sucking air you would have aerated oil. This is not the same as cavitation. Good to see someone coming back with a progress report on their problem.
Have a look at the thread called "Case W24B Allison transmission parts" by "candor" in this section. (He might be able to give you an opinion about your noise levels). Look for Posts by "jmatthai". He knows his Allisons and is very helpful.
update I did some further work on this machine today.I drained the transmission and checked certain areas of the transmission where air could be getting sucked in. Declutch area checked out ok,Suction tube area we have a problem. I segregated the suction tube and pressurized it to 20 pounds and i could hear air exiting the suction tube wayyyy up inside the transmission. Here is my thought, first Is there any possible way to access the tube nut where the tube is attached to the backside of the pump, inside the transmission?? secondly if i remove the hydraulic pump and the transmission pump i can look down the inside of the suction tube. My thought is that if i clean it really well i may be able to rtv silicone the INSIDE of the suction tube where it meets the nut and pump housing and let it dry. Its just a crutch to get through this winter season. What are your thoughts????????
Please don't put silicone where you are thinking. It will end up through all your trans. control valves no matter how long you let it cure for. Why don't you send jmatthai a private message or email and ask him to have a look at your thread.
I thought about not siliconing the inside of the joint but im kind of left without a choice. I checked the oil flow and the worst case scenario is that the rtv comes loose and it will go directly through the filter. If it were to go through the valve body first i wouldnt even consider it. My issue is its a snow machine which is still operable so removing the cab and transmission isnt an option until late march. I emailed jmatthai and havent heard back yet....
Sounds like you got yourself covered then. I couldn't even imagine trying to work on a machine when it's that cold! But thanks - you shamed me into going out and putting the cab down on my truck in the rain.