Bobcat 863F valve lock on, no tilt or lift

   / Bobcat 863F valve lock on, no tilt or lift #1  

Adalbert

New member
Joined
Dec 21, 2014
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7
Location
Tivoli
Tractor
Bobcat 863F Dec/1998
Just finished resealing the control valve spools, pump control spools/sleeves, and replacing tilt actuator in my 1998 863F with AHC controls.

this was prompted by a malfunctioning tilt actuator which was causing the valve lock to engage at first randomly but very soon every time I attempted to use tilt.
turned out the actuator was full of hydraulic oil which had been getting past the control valve spools.

so I put everything back together and now the valve lock is engaged(LED light doesn't turn on) as soon as I press the green push to operate button.

I've gone over much of the wiring and cleaned any terminals that looked corroded(basically 2 which where probably not related)
I also ran a new heavier 2/0 AWG(original was 1/0 AWG) main as well as supplemental ground cable to the battery.

The BICS fuse near the timing belt area seems fine(no corrosion).

still no tilt or lift.

I've also disconnected the hand controls to see if they were causing the issue but the lock light was still off.

could the problem be caused by a relay?
There are a few near the controls and some next to the engine under the air filter.
The "switch power" relay has some melted plastic around the male terminal and corresponding female wire terminal.
I switched it with the glow plug relay to test but valve is still locked.

Something I didn't notice previously is that when I first turn the key, all of the lights on the BICS panel light up for about two seconds.
But as before, when I lower the seat bar and press the green button all of the lights are on except the valve lock.

Any Ideas?
 
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   / Bobcat 863F valve lock on, no tilt or lift #2  
If there was any type of open ciruit or short in wiring between the conrol module and the BICS solenoid that light should be blinking, series of flashes will indicat what type of problem. Controller lights all come on with the key means controller is geting power and it works off 1 12v input and 1 ground. Look on the left handle, there should be 2 small green lights that should come on, stay on steady, when AHC is activated. If one of these lights is blinking indicates a problem in AHC system (handle, actuator, or AHC controller). One light is for left hand (lift circuit), other is Right hand (tilt circuit). When you ouhs the Presss To Operate button, system will check the Left handle first if it is OK it will then check Left. If one light flassing and other is OFF, problem is in Lift circuit. If one light on and other is Off or blinking problem is in Tilt circuit. If both are Off, very likely problem is in the AHC controller (large aluminum covered box).
A short to ground in actuator motor could cause the controller to fail, with amperage feeding back to controller through the ground circuit.
 
   / Bobcat 863F valve lock on, no tilt or lift
  • Thread Starter
#3  
If there was any type of open ciruit or short in wiring between the conrol module and the BICS solenoid that light should be blinking, series of flashes will indicat what type of problem. Controller lights all come on with the key means controller is geting power and it works off 1 12v input and 1 ground. Look on the left handle, there should be 2 small green lights that should come on, stay on steady, when AHC is activated. If one of these lights is blinking indicates a problem in AHC system (handle, actuator, or AHC controller). One light is for left hand (lift circuit), other is Right hand (tilt circuit). When you ouhs the Presss To Operate button, system will check the Left handle first if it is OK it will then check Left. If one light flassing and other is OFF, problem is in Lift circuit. If one light on and other is Off or blinking problem is in Tilt circuit. If both are Off, very likely problem is in the AHC controller (large aluminum covered box).
A short to ground in actuator motor could cause the controller to fail, with amperage feeding back to controller through the ground circuit.

Thanks for the reply.
Unfortunately my left control handle has never had working lights as long as I've owned the machine.

Two days ago I finally decided to remove the valve lock solenoid and hook it up to 12v.
There was no change that I could perceive when applying 12v, it did not seem to magnetize at all.
I placed various metal parts at both ends but it did not push or attract them.
I had gotten 9ohms with it installed and 10ohms with it pulled out.
It had been rather difficult to remove it, a bit rusty on the inside..the seals probably could use replacement...

planning to order a new solenoid today.
 
   / Bobcat 863F valve lock on, no tilt or lift
  • Thread Starter
#4  
If there was any type of open ciruit or short in wiring between the conrol module and the BICS solenoid that light should be blinking, series of flashes will indicat what type of problem. Controller lights all come on with the key means controller is geting power and it works off 1 12v input and 1 ground. Look on the left handle, there should be 2 small green lights that should come on, stay on steady, when AHC is activated. If one of these lights is blinking indicates a problem in AHC system (handle, actuator, or AHC controller). One light is for left hand (lift circuit), other is Right hand (tilt circuit). When you ouhs the Presss To Operate button, system will check the Left handle first if it is OK it will then check Left. If one light flassing and other is OFF, problem is in Lift circuit. If one light on and other is Off or blinking problem is in Tilt circuit. If both are Off, very likely problem is in the AHC controller (large aluminum covered box).
A short to ground in actuator motor could cause the controller to fail, with amperage feeding back to controller through the ground circuit.

After many hours of troubleshooting over the course of about a dozen phone calls with a Bobcat service technician(trains Bobcat dealers),who in addition to his own knowledge corresponded with some "old timers" who worked at bobcat during the building of this model,
we came to the conclusion that the only next logical step would be to install the "AHC Upgrade Kit W/Push Button Float" part number 6727297.
It only cost about $3,200:eek: so I thought why not...:confused2:

Just installed the kit today.
still no tilt or lift.
seems that the kit doesn't replace all possible problem areas.
also, before I replaced the replacement kit, the error lights on the left hand control would show errors. with the new set up, the lights don't go on at all. only the lights on the BICS panel light up.


planning to call bobcat again on Monday...

The following link contains a thread that explains my situation a bit more, it starts off with an issue I had with a bad actuator. then it continues to the current predicament...
Tilt and Lift not working on Bobcat 863
 
   / Bobcat 863F valve lock on, no tilt or lift #5  
Can you post the SN#. Is the work pump working?
 
   / Bobcat 863F valve lock on, no tilt or lift
  • Thread Starter
#6  
Finally found some time to work on this again....

Jabonee,
the SN# is *514*427*853*

As far as I know the pump is working.
the machine is drivable, just the tilt and lift wont work.
to recap:
*New actuator because old one was flooded.
*Resealed both tilt and lift spools.
*New valve lock solenoid
*New BICS panel
*AHC upgrade kit(includes new main controller and both hand controls)
*Upgraded main ground to starter and battery with heavier gauge cable.
*Replaced rusted shield(kick plate under seat that hand controls come out of) with new one. This was something I did along with replacing the lift actuator, "the problem" started right after this.

Any instructions on checking the main AHC harness for a bad a ground or other possible issues?

On the old left handle, the lights blinked a code.
with ignition key turned halfway:
left LED was on while right LED had a two blink sequence.

With actuators(approximately in neutral position) and disconnected from spools with the the ignition key turned halfway:
Both LEDs turned off for about two seconds during which time the tilt actuator retracted fully and then symptoms returned.

With the new "Upgrade Kit" the LEDs in the new handle don't turn on at all
 
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   / Bobcat 863F valve lock on, no tilt or lift #7  
Sounds like your getting quite a bit of $$ tied up in this repair. Is the BICs valve indicator light lit when you lower the lap bar and press the PTO button?
 
   / Bobcat 863F valve lock on, no tilt or lift
  • Thread Starter
#8  
valve lock light does not turn on at all.

all other lights(including traction) do turn on after seat bar is lowered and press to operate is engaged.

I have done these part replacements myself so at least I haven't been paying labor...
everyone I've spoken to has been stumped. including a bobcat tech who trains dealers.

I've replaced the valve lock solenoid but not the related valve stem part#6676249.
it looked ok when I pulled it out, but I had to put it right back in because hydraulic fluid started rushing out.
any way to test it?
 
   / Bobcat 863F valve lock on, no tilt or lift #9  
The BICs valve light not lit or flashing indicates an open circuit. I think you stated you replaced the BICs controller too? I would check continuity on supply and ground from BICs coil to controller.Thats why your" snake eyes" on left stick are not lighting up:thumbsup:
 
   / Bobcat 863F valve lock on, no tilt or lift
  • Thread Starter
#10  
sounds like a plan, i've gone over most grounds numerous times in the past year, but not supply lines.
The "snake eyes" did work on the old handle.

Should I just use a test light or an ohm meter?
 
 
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