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Bucket keeps curling/hyd problem?

h8cat

Member
Joined
Dec 27, 2010
Messages
12
Location
Meridian, ID
I have an 04 or 05 Cat 267B track skid. whe the machine is running at idle or full throttle the bucket curls all the way up and you can hear the pressure build up. If you pull back on the joystick and slowly re\otate it to dump the bucket will slowly dump. Cat in idaho said it was the complete joystick assembly that was bad. Anybosy else have this issue and if so was it the stick or something else. Any ideas will be appreciated. Thank you.
 

JeremiahSr

Well-Known Member
Joined
Sep 10, 2010
Messages
204
Location
Houston, Tx
Occupation
Vice Pres./General man./Technician
If that hydraulic system is controlled electronically could just need to run calibration on it. The electric actuators are controlled by a signal received from controller that receives it's signal from joystick. Could be the joystick position sensor, bad wiring or the controller. Could even be one of the cylinders' seals are coming apart and trash got in control valve hanging up the spool. You rreally need someone in your area to run CAT ET on it to see if there are any codes and to run joystick actuator calibration to make sure it is not that.
Now if it does not have electric..meaning it is linkaged...i think all 267B's are though?.....the linkage or cable controlling it are hung.
Give me the PIN and i can see how it is setup. Good luck!
 

Tigerotor77W

Senior Member
Joined
Nov 1, 2004
Messages
1,014
Location
Michigan
Occupation
Engineer
Jeremiah, it's a pilot system, so it sounds like something in the pilot system is awry. What exactly... that I'm not sure of.
 

JeremiahSr

Well-Known Member
Joined
Sep 10, 2010
Messages
204
Location
Houston, Tx
Occupation
Vice Pres./General man./Technician
Ahhh.a pilot system. The PPC valve has little spools inside them. It is the spool just above the number 11 spring in this parts picture. Could be a broke spring on main spool inside control valve or the spool hung still. 80% of the time it winds up being this spool in the PPCV. Tear down the bucket curl spool and that is probally what is going on. Take some needle nose pliers and work that little spool out, sand it up with some emory paper. (or however you spell emery?) You do need some mechanical skill to tackle this one but take your time, relieve pressure in hydraulic tank and give it a try. Good luck!
 

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bobcatmechanic

Senior Member
Joined
Mar 26, 2008
Messages
429
Location
kansas
Occupation
bobcat mechanic
do the aux hyd cause a problem on the cats? On the bobcats if they are stuck on it messes with everything. Does it do it from start up before you release the safety interlocks or after?
 

h8cat

Member
Joined
Dec 27, 2010
Messages
12
Location
Meridian, ID
I took apart the pilot valve and everything seemed ok. I will send it to cat to do a diagnostic. it does it from start up. Before I release the safety.
 

h8cat

Member
Joined
Dec 27, 2010
Messages
12
Location
Meridian, ID
I took apart the pilot valve and everything seemed ok. I will send it to cat to do a diagnostic. it does it from start up. Before I release the safety.
Well I took it to cat and no codes in the computer. They think its the joystick valve. 920.00 dollars. Ouch. I am starting to agree with them, as i have rebuilt the valve body, joystick and main and it is still doing the curl. Any more Ideas will be greatly appreciated. Thanks.
 

Lee-online

Senior Member
Joined
Jan 16, 2010
Messages
1,023
Location
In a van, down by the river
it does it from start up. Before I release the safety.

Then it is NOT the pilot control valve/joy stick. Until the interlock is released the joystick has no pilot pressure feeding it.

There is a problem with the spool in the main valve. Either it is sticking because of debris or something is broken, possibly a centering spring.
 

bobcatmechanic

Senior Member
Joined
Mar 26, 2008
Messages
429
Location
kansas
Occupation
bobcat mechanic
sounds like a valve stuck like everyone has said. on bobcats they use a spool and magnetic coils to run the aux a stem may be bad with debri or just cocked in the bore and allowing oil to flow by. On most machines the lift has a safety hyd lock as not to be able to get oil to the cyliders until it has power going to the coil or valve to release. That way the arms can not lift and kill you as you are entering/ exiting the machine. do your lift arms lift regardless of what you do when you move the funtions and dont come down unless you shut the machine off and use the bypass lower valve?

I agree on the pilot pressure not being at the controls until you press the safety release button.
 
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