hydrolics

trx250r180

The Junk Peddler
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May 7, 2013
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anyone in here know about hydrolics ,my skid steer main pump is growling and losing hydrolic power when warm ,have to rev rpm's higher than i like to get work done ,changed both filters and dumped all the fluid and put new in ,still growling when warms up and loses hydrolic power ,any ideas ? pump need rebuilt ? crap stuck in a valve ?
 

Chity_Avatar

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Pump or weak relief valve. Depending on the machine you may or may not be able to rebuild the pump. If the pump lobes or gears are worn you have a chance but if the lobes have worn the ends of the cases than you will more than likely be replacing the pump. Some pumps have brass or bronze end plates that can be replaced with the lobes. Only doing a pressure check before and after the relief valve will tell what is wrong. Should be ports in the valve body to screw a gauge in to do both tests. I assume you are talking about the bucket control pump and not the main drive pump?
 

Barneyrb

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Jul 10, 2013
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In addition to the filter (actually before the filter) there is *usually* a screen to keep the larger chunks out of the filter. I have seen those caked up enough to greatly impede oil flow and cause "low fluid" type of problems.

Who made the equipment and what is the model number.........
 
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trx250r180

The Junk Peddler
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its an older like a 75 ford cl-30 ,i have another one at work says ericson on it ,it's same machine ,has a wisconsin air cooled engine ,i once lost all drive years ago started taking pump off ,and in the hose was a chunk of an inner tube ,how that got in the tank is beyond me ,it seems like a fluid restiction problem ,works fine when cold ,run hard for 20-30 min starts losing power and i have to rev the engine up ,or let it cool off ,i tried an elec fan on the oil cooler ,did not seem to help ,a clogged screen sounds like may do this ,if i can figure out where it is ,right on bottom of oil tank there is a one way valve like off a well ,wonder if its by there ?,the lh drive motor does leak some ,but works ok to get me around ,it fills the lh chain drive case ,i can drain it ,and fluid looks fine so can dump back in the tank ,i'm sure doing this i could have plugged something up by now if crap falls in the tank

this has only one pump on back of engine ,feeding to a splitter valve ,like a log splitter but 4 passages ,2 for bucket ,2 for forward/reverse
 
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trx250r180

The Junk Peddler
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In addition to the filter (actually before the filter) there is *usually* a screen to keep the larger chunks out of the filter. I have seen those caked up enough to greatly impede oil flow and cause "low fluid" type of problems.

Who made the equipment and what is the model number.........
Sounds to me like the pump is cavitating probabley from oil starvation in other words something on the suction side .It could also be an air leak which causes something akin to a saw running lean .Again on the suction side .

I downloaded a manual online ,looks like there is a strainer screen ,tubular shaped inside the hyd oil tank ,hopefully this is the problem ,i have had the machine almost 10 years i think ,its never been serviced ,am sure its caked with gunk ,feels like a restriction when its first ran ,get things flowing it works for a while then when hot gives fits ,the fluid never used to get this hot ,cavitating oil would create heat i would think ,glad i paid the 20 bucks for a manual ,the access plate is on top of tank easy to get at ,saved me from tearing all the seats and floors out
 

Barneyrb

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Jul 10, 2013
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I downloaded a manual online ,looks like there is a strainer screen ,tubular shaped inside the hyd oil tank ,hopefully this is the problem ,i have had the machine almost 10 years i think ,its never been serviced ,am sure its caked with gunk ,feels like a restriction when its first ran ,get things flowing it works for a while then when hot gives fits ,the fluid never used to get this hot ,cavitating oil would create heat i would think ,glad i paid the 20 bucks for a manual ,the access plate is on top of tank easy to get at ,saved me from tearing all the seats and floors out
On 99% of the tractors I have worked on the screen is usually where the suction hose comes out of the case and I think that is what you are looking at......now I'm just hoping it is stopped up a little because that is a cheap fix, everything else is like the monkey peeing into a cash register, it runs into money.....
 
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trx250r180

The Junk Peddler
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well i drained the hydro oil out of the tank ,there is a plate on top of the tank that unbolts to get into the tank ,someone made a gasket from an inner tube for the plate ,it was rotted in the middle ,this explains the chunk of inner tube i found crammed in a line a few years ago ,the screen filter has broken off where it threads to bottom of tank ,so a 1 inch pipe sucking everything that will fit into it is my suction feed now ,i pulled the main feed line down to the first hydraulic pump on back of transmision ,took it apart ,everything looks nice in there ,i don't see how anymore of that tube they used for gasket could get through ,but it's possible ,the pressure line after the pump feeds to the bottom of the transmision ,it must branch the fluid in there for the hand controls ,i guess next step is take every hose off one by one and blow through them ,or run a fish tape through them till i get to the end of the system ,hopefully the crap got through the transmision ,and is caught in a fitting ,i will stop by hydraulic shop see if they have some kind of screw in screen filter today ,i'm hoping if i take the lines off in/out of transmision ports and move the lever i can blow air through there and not have to tear that all the way down
 

srcarr52

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Feb 11, 2013
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Hopefully all the trash the pump sucked up didn't tear it up. Usually a growling from a pump either means low feed flow or disaster has struck.
 
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Barneyrb

razorback sympathizer
Jul 10, 2013
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North of the Coonazz line but still in Louis
well i drained the hydro oil out of the tank ,there is a plate on top of the tank that unbolts to get into the tank ,someone made a gasket from an inner tube for the plate ,it was rotted in the middle ,this explains the chunk of inner tube i found crammed in a line a few years ago ,the screen filter has broken off where it threads to bottom of tank ,so a 1 inch pipe sucking everything that will fit into it is my suction feed now ,i pulled the main feed line down to the first hydraulic pump on back of transmision ,took it apart ,everything looks nice in there ,i don't see how anymore of that tube they used for gasket could get through ,but it's possible ,the pressure line after the pump feeds to the bottom of the transmision ,it must branch the fluid in there for the hand controls ,i guess next step is take every hose off one by one and blow through them ,or run a fish tape through them till i get to the end of the system ,hopefully the crap got through the transmision ,and is caught in a fitting ,i will stop by hydraulic shop see if they have some kind of screw in screen filter today ,i'm hoping if i take the lines off in/out of transmision ports and move the lever i can blow air through there and not have to tear that all the way down
The spin on filter is usually between the screen and pump on the suction line.....
 

trx250r180

The Junk Peddler
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reading online skid steer forum ,and in my manual i downloaded , it says 10-30 motor oil in hydraulic tank because it has non gear drive pump ? i have been putting hydraulic tractor oil in ,is it possible stuffs too thin ?


quote off another forum

Re: what hydraulic oil should i use in skid steer
Posted: 11/05/2006 09:42 PM
Any 10W30 or 10W40 motor oil will work. NEVER run hydraulic oil, its too thin.

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Jimmy in NC

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reading online skid steer forum ,and in my manual i downloaded , it says 10-30 motor oil in hydraulic tank because it has non gear drive pump ? i have been putting hydraulic tractor oil in ,is it possible stuffs too thin ?


quote off another forum

Re: what hydraulic oil should i use in skid steer
Posted: 11/05/2006 09:42 PM
Any 10W30 or 10W40 motor oil will work. NEVER run hydraulic oil, its too thin.

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Most hydraulic is 32 weight. Most of the difference is in the additive package. Try draining it and see where it goes....nothing to loose at this point.
 
I suppose the actual SAE weight of normal hydraulic fluid is debatable .I had always assumed it to be SAE 10WT .

Some old equipment such as my antique Cat D4 dozers had stamped right on the cap for the oil to use 30WT .

However in cold wether it was very slow on the uptake until it got warmed up .Now something like Dexron tranny fluid will take more heat than motor oil and is more fluid at lower temperatures .

I once worked for a mllionaire contractor who was so cheap you couldn't pound a flax seed up his azz with a ball peen hammer .They blew a hose on one of the line trucks and pumped out 50 gallons of type a fluid in about 3 minutes flat .

The stingy bastage had them dump in regular general purpose 10WT hydraulic fluid because it was cheaper .Now this was Jan .in Ohio,cold .It took about 45 minutes to warm up while he had two journeymen and a groundman waiting for the freakin truck to run .He got the message and changed it back .
 
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trx250r180

The Junk Peddler
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at my fuel station where i get gas they have one called hyd tractor oil ,i think it says 10wt on the pump think its is the aw32 ? ,that's what i put in there origianally,i have taken all my lines off and blew compressed air through them ,now when i got to the 2 external oil type filters ,it blew back at me so i took the first filter off and got through ,there is a one way valve right before the tank on return ,i got a lot of white milky sticky oil out of there once got air through ,i picked up some 15-40 oil at the pumps to try ,its all they had besides 2 types of hydraulic oils and chainsaw bar oil ,yes we can get chainsaw bar oil at the gas pumps here :cool:

i will try the 15-40 that's what the new skid loaders seem to be running from what iv'e read to keep it simple for the service ,one type of oil for everything ,the oil i drained out has some bubbles and water contamination ,hopefully the fresh stuff gets me going ,otherwise time for a newer machine
 
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