Hi Everyone, I have a Bobcat 753F which works great for about the first 20 minutes, then I loose lift and tilt on the bucket, but it still drives. If I let it sit for a few hours the bucket functions come back just for a much shorter time. I thought it was the BICs solenoid, however when I replaced it the problem still exists. I even tried putting another solenoid on after it quit, and ran the solenoid straight from a 12Vbattery to ensure that it wasn't a wiring issue, same problem. I talked to the local bobcat dealer and they said it sounded like the BICs. The next option is to replace the BICs spool, however I was hoping I could get some feedback from others. Should I be looking at something else? Thanks for any help
Welcome to HEF calliso6. When you say you lose lift and tilt operations, does it put a load on the engine when you lift or tilt yet functions won't work? Or does it not change the load on the engine at all when you lift/tilt?
only way to tell whats going on is to take a look at the BICS controller idiot lights when the problem happens. one or more of the lights are probably flashing. look in the operators manual to find the flash codes. things like loose or corroded battery connections, pinched or worn spots in harnesses, oil in harness connectors, loose terminals inside connectors can cause the problems you are having. :drinkup :drinkup
If I press the pedals down to lift or tilt you can hear the engine and pump trying you can even see the hydraulic lines move a little because it is trying to pump fluid but it is like it is dead headed.
All BIC's lights are on solid no codes. I have checked the harness, Also I suspect if it was a harness problem it wouldn't be so consistent with time.
if you are positive theres no issue with the bics harness connector in the main harness, my next step would be to locate the ground wires that run from the bics coil and brake solenoid in the main harness. bobcat spliced several grounds together in the main harness, often the ground that runs back to the battery or engine block is damaged. resplice the wiring and add another ground over to the frame at a convienent location. sometimes cures the problem. :drinkup
Imo It sounds like hydraulic return problem hydraulic Diagram and some pressure test should sort that out. Have you had any Recent repairs that could of left plugs or rags in system? Possibly is there Solenoid controlling return oil to cooler / tank.
I have the same problem, but my 753G is coming up with code 18-06. Bad ground to spool coils. My ground wires are #2370 & #2380. I'm searching for their origin in order to resolve the problem. The spool coils are clicking when I power them manually.
It seems as though I figured it out today. The manual release valve is preventing flow of fluid, if I turn the valve it releases the pressure and bucket starts to work again. On Monday it looks like I will be order a new valve.
I really don't think your problem is the manual release valve callis06, but it is an interesting clue. And no, I can't say I know what the problem is, but many times a problem has to be noodled out, and clues like this help. I think it's possible that it's not an electrical problem since you not only replaced the BICS coil, but you applied direct 12V to it as well. BTW, you did connect a good ground to it as well when you did that test, no? Assuming it's not an electrical or coil problem, then with must have a problem with either the BICS coil spool, or problem with internal routing of the pressure that releases the lock valves. When you energize the BICS coil, it shifts the spool which directs pressure to the lock valves for lift and tilt. It appears that during use of the machine that this pressure (that holds lock valves open) seems to loose pressure allowing lock valves to close, blocking oil in the lift/tilt circuits. Now, at this point, you have oil pressure against the lift lock valve in the lift circuit, and it seems the internal BICS circuit can't overcome the pressure in the lift circuit to unlock the valve. I know, that sounds crazy, but when you release this pressure via the manual release valve, now all of a sudden the BICS circuit can pop open both lift lock and tilt lock. See that's the thing, the manual release valve has nothing to do with the tilt circuit. The only way the manual release has a connection to the tilt circuit is via the internal BICS pressure that opens the lock valves. It just seems you're loosing internal BICS pressure. Now if this theory has merit, I would pull the BICS spool and the lift and tilt lock valves, inspect the o-rings closely. For that matter, replace the o-rings and try it out. If that doesn't fix I think I'd replace the BICS spool. If that doesn't fix it, possibly a crack in the control valve, or faulty o-rings that seal where the control valves fits together that when it warms up then gaps open up and you loose BICS internal pressure. If all this doesn't work, my brain is running out of suggestions quickly and crewchief better come up with something before my head explodes.
Thank You for the response this helps out quite a bit. I honestly was hoping this would give more insight because I didn't think the manual release valve should be working in that manner. I will take a look at the lock valves this weekend. I already replaced the BICS spool.
I bench tested the bics solenoid from my machine today. After that I hooked it to the wiring harness in order to make sure I was getting power and ground to the solenoid. It seems to be working, but now I'm getting code 27 - 02. The lift and tilt will not work, and the engine labors when the peddles are pressed. Can anyone tell me what solenoid is related to the front rod on a 753G, and what may be causing this code?
how did this get resolved anyone know!!!!!
Not sure how it was resolved but I had same problem, I disconnected my park brake switch, lifted the cab and unplugged it and problem was fixed, assume switch was faulty