Shimming Pressure Relief Valve

   / Shimming Pressure Relief Valve #1  

Skinnyman

Silver Member
Joined
Aug 6, 2009
Messages
117
Location
Wilmington, NC
Tractor
Bobcat CT235
Have any of you folks shimmed or adjusted the pressure relief valve to achieve max system pressure for the loader? Per the manual, max system pressure is 2611 psi. Warmed up and at 2000 rpm I am only getting 2400 psi. I think it would be worth the effort to get to 2600 psi. Any help on the shimmning or adjusting process would be so welcomed, like location of PRV and where to obtain shims, etc...I have a 2009 CT235.
 
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   / Shimming Pressure Relief Valve #2  
Just for clarification, are you only getting up to 2400 psi or is the valve audibly relieving pressure at 2400 psi?
 
   / Shimming Pressure Relief Valve #3  
Have any of you folks shimmed or adjusted the pressure relief valve to
achieve max system pressure for the loader? Per the manual, max system pressure is 2611 psi.

My CT230 arrived new with the RV set at 3000psi. Setting the system/FEL RV properly is very easy, and
no shims are used. It is under the right side floorboard. Remove the cap and turn the inner screw clockwise
for more pressure. The service manual shows you where it is.

Note that these tractors from Kioti or Bobcat (DaeDong M27) are the same, but the Kioti is specced at 2560psi.
 
   / Shimming Pressure Relief Valve
  • Thread Starter
#4  
Milkman, with the gage on the quick connect port for lowering the loader and opening and holding the port open, I am only registering 2400 psi. I held the port open until the gage was at max reading. I am not sure I have heard the relief valve open.
 
   / Shimming Pressure Relief Valve #5  
Hook the gauge to the lift Up connector and test it pulling back on the lever. If moving the lever too far in down the spool might get to close to going into float and start bleeding some oil off there. If you have rear remote, plug your gauge in there and activate the remote lever. Rear remotes work off the loader valve relief.
 
   / Shimming Pressure Relief Valve
  • Thread Starter
#6  
Good tip about the float position. I have already adjusted, but will go back verify using the lift port.
Thanks guys for the help.
 
   / Shimming Pressure Relief Valve
  • Thread Starter
#7  
Re-checked psi using the port to lift loader, still showing 2600 psi. Good tip, feel better after re-checking.
 
   / Shimming Pressure Relief Valve #8  
Actually, your 2611 psi, was probably set at the factory for the 3pt before any attachments, and is the reference to set the other valves to the same setting.

So if you have a loader and remotes, you would set all the relief valves the same. That would also make the loader relief valve the master relief since it is first in the series path of the fluid.

It would be a good idea to install a hyd gage in the IN port of the loader valve where you can see it for monitoring and trouble shooting the hyd system.
 
   / Shimming Pressure Relief Valve
  • Thread Starter
#9  
Thanks JJ. Have I errored upping the loader relief valve from 2400 to 2600? The manual quoted "system relief @ quick couplers 2611 psi".
 
   / Shimming Pressure Relief Valve #10  
The CT/CK has one regular RV (2500-2600psi) and one shock RV (about 3000psi) in the
3-pt valve. There is no separate RV for the FEL, just the one I mentioned above. Only
the first regular RV is adjustable.

Since you mentioned the RV spec for your CT235, I assumed you have the service manual,
which shows you where the RV is.
 
 
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