Bobcat 310 sluggish hydraulics

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Hammerhead63

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Mar 20, 2021
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Good evening all. Recently bought a new to me 310 and am reasonably happy with it but it really struggles to lift the bucket under load. So my question is, is the pump rebuildable? I've searched for kits but there don't seem to be any out there. Any assistance or advice would be very much appreciated. Doug
 
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Hammerhead63

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Mar 20, 2021
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Looks like it's a gear pump, no kits for them, you need to replace the whole thing:
https://loaderpartssource.com/bobcat-parts/bobcat-310-skid-steer-single-gear-pump.html
It does sound like the pump is sad, you need to hook up a test gauge to know for sure. Loader parts source may be able to help test it too, depending on how far away they are or if shipping it there is worth it for a test.
Thanks! Yeah I was afraid of that. I'll find a way to get it tested. My sons a mechanic so hopefully he can give me ideas. That or drag it over to a local hydraulics shop.
 
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Hammerhead63

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Thanks! Yeah I was afraid of that. I'll find a way to get it tested. My sons a mechanic so hopefully he can give me ideas. That or drag it over to a local hydraulics shop.
So thinking more about my situation and the fact that my tilt bucket operates just fine with a full load of wet clay tells me that it's not likely the pump otherwise it would be slow there too. So now the question is whether it's the control valve or possibly a linkage adjustment issue? Anyone got diagnostics ideas? Thanks, Doug
 

Tazza

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So thinking more about my situation and the fact that my tilt bucket operates just fine with a full load of wet clay tells me that it's not likely the pump otherwise it would be slow there too. So now the question is whether it's the control valve or possibly a linkage adjustment issue? Anyone got diagnostics ideas? Thanks, Doug
If any of your other functions work as they should with good power, the pump is not the issue, it has to be something like a relief valve on that segment of the control block. Damaged piston seals in the cylinders would cause it to fall down on it's own, but i'd think you'd notice that.
 
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Hammerhead63

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If any of your other functions work as they should with good power, the pump is not the issue, it has to be something like a relief valve on that segment of the control block. Damaged piston seals in the cylinders would cause it to fall down on it's own, but i'd think you'd notice that.
Thanks Taxza. Do you happen to know if there's a rebuild kit for this control valve?
 

flyerdan

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Thanks Taxza. Do you happen to know if there's a rebuild kit for this control valve?
If you go to Bobcat Parts Online and put your serial number in the tab it will pull up all parts relevant to your machine, including the correct valve assembly with the rebuild kit numbers. You can then use those numbers to search for the best price.
There is also a Melroe control valve manual in the manual thread that will help in disassembly and putting things back together right.
 

Tazza

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If you go to Bobcat Parts Online and put your serial number in the tab it will pull up all parts relevant to your machine, including the correct valve assembly with the rebuild kit numbers. You can then use those numbers to search for the best price.
There is also a Melroe control valve manual in the manual thread that will help in disassembly and putting things back together right.
Seals and Orings you can get from hydraulics seal shops too, but looking at the bobcat site is a good idea, it shows you what parts are in there and possibly an idea of what could be wrong.
 

Hotrod1830

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Seals and Orings you can get from hydraulics seal shops too, but looking at the bobcat site is a good idea, it shows you what parts are in there and possibly an idea of what could be wrong.
these machines are clutch drive. The only way the operator knows the hydraulic fluid is low is when the hydro's stop working correctly. Check the fluid level in the case before you do anything. Mine would do the same when the fluid was low. 2 Plugs on the right side. lower plug is lower limit, upper plug is upper limit. Fill it with 10/30 engine oil till it runs out the lower plug and your done. Operate hydro's and recheck. repeat until the level is stable.
 
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Hammerhead63

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Mar 20, 2021
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these machines are clutch drive. The only way the operator knows the hydraulic fluid is low is when the hydro's stop working correctly. Check the fluid level in the case before you do anything. Mine would do the same when the fluid was low. 2 Plugs on the right side. lower plug is lower limit, upper plug is upper limit. Fill it with 10/30 engine oil till it runs out the lower plug and your done. Operate hydro's and recheck. repeat until the level is stable.
Thanks Hotrod. I'll check the level. I was also curious if it's possible that the bypass pressure has slipped and wondering how to check and correct it if it's too low.
 
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Hammerhead63

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Mar 20, 2021
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these machines are clutch drive. The only way the operator knows the hydraulic fluid is low is when the hydro's stop working correctly. Check the fluid level in the case before you do anything. Mine would do the same when the fluid was low. 2 Plugs on the right side. lower plug is lower limit, upper plug is upper limit. Fill it with 10/30 engine oil till it runs out the lower plug and your done. Operate hydro's and recheck. repeat until the level is stable.
Thanks Hotrod. I'll check the level. I was also curious if the bypass pressure could have slipped and caused the issue. Any insight to how I can check the pressure and adjust it if it's slipped? Thanks again!
 

Hotrod1830

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Thanks Hotrod. I'll check the level. I was also curious if the bypass pressure could have slipped and caused the issue. Any insight to how I can check the pressure and adjust it if it's slipped? Thanks again!
If i t had slipped, you would more than likely just have weak hydro's. Only idea I have for checking it is put a gauge one one of the cylinder hoses and deadhead the other side. Work the hydros until the gauge is at the max and that is your available pressure. Should be close to the system spec @ operating RPM. I think it was somewhere around 1500 psi. maybe someone has a manual to verify
 

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