883G Skid Steer attachment aux hydraulic moves the equipment (a dozer blade) one way (left) but not the other (right). Solenoid activity is heard when moving the center thumb switch to the right, which turns the blade left, in other words, right side of blade goes forward. No sound is heard moving switch to the left, as such, the left side of the blade does not move forward. Digging deeper, the switch (it's a potentiometer for the variable auxiliary) on handle pn# 6680418 is using three of the eight wires inside C409 connector. I have used an ohm meter to test resistance across these wires on the existing handle and also a new handle. 4300 -- pin B -- wht 4320 -- pin D -- wht/red 4310 -- pin C -- wht/blk The resistance values are nearly identical between the two handles. Existing handle: Pins D to B switch centered: 5.8 ohm D to B left: 3.7 ohm right: 8 ohm D to C center: 6.3 ohm D to C left: 8.3 ohm right: 4.3 ohm. New handle values respectively: 6.0, 4.3, 8.3 6.3, 8.3, 4.3 The existing handle being a tad bit lower resistance on the left might have someone change out their handle just because. Yet I'm inclined to believe my wht/blk to wire 4310 is somehow not talking to the solenoid. Any thoughts? I don't have any electrical diagrams or ideas where the other ends of wires 4300, 4310, 4320 are located as I've got the cab tipped up. Inside the wiring harness are many green and black wires with numbers printed on their casings. Lots of greasy black soot all over the entire batch of wiring harnesses. Does anyone also have a good cleaning suggestion that won't deteriorate the components?
I don't have any info on the 883, but typical Bobcat would be the paddle switch on the right handle sends input to the main controller (ECU), the main controller takes this input and sends a PWM signal to the proportional solenoid coils on the main control valve to operate the auxiliary hydraulic circuit. Since you've worked with both original handle and replacement handle I doubt wht/blk wire 4310 is the problem. 4310 is a wire that sends input to the main controller and the chances of that wire circuit being faulty on both the old handle as well as the new is like winning powerball. First we have to verify the problem is with the machine and not the attachment. Have you operated the auxiliary functions with no attachment connected? If the machine is working proper, with no attachment connected to the machine, you should be able to load the engine when you operate the paddle switch to the left or right. If it doesn't load the engine in one direction of the paddle switch, the next thing I'd do is remove the proportional solenoid valves from the main control valve and swap them, see if the problem reverses.
like willie mentioned, you can swap the aux solenoids/stems and see if the problem "moves" to the otehr direction you can also remove the coils from the stems, activate the aux function in both directions use a small screwdriver or oring pick inside the coil to see if it's magnetizing. typically if you have an electrical problem the machine will throw a fault code, if it doesnt the problem is probably the solenoid stem itself sticking. another possibility is that one of the aux spool centering springs is broken, or the spool itself may be sticking
There aren't any fault codes. The engine load is heard in one direction only. Not sure how to go about this swapping around of solenoids, without seeing a picture of what parts we're talking about with the cab tipped up.
2 aux coils are located in the top of the control valve one at the front and 1 at the rear they may be sticking straight up, or facing the inside of the machine.
Great comments. I'm lost without photos or sketches of the parts. Can these suggestions be done with seat bar down, cab tipped up, engine running, bics engaged? So much greasy dirt. I'm used to using foamy engine brite and a high pressure wand to clean car engines.
Like crewchief said, the two solenoid valve may be sticking straight up on the top of the control valve body or they may be pointing inward at the top of the control valve, can't say which way yours is oriented as Bobcat used many different valve configurations over the years. This pic is a typical control valve on a 773 G series, the two coils at the top of the control valve are the aux circuit solenoid valves.
Just finished cleaning and swapping solenoids. On 883G (sn 5201xxxxx and up) the front stem faces inward, back stem upward. I got no changes in the symptoms. So not sure if the back or front is bad when pushing thumb paddle left. Also found a blown 25A fuse for "UNSWITCH" inside the panel below the seat. Put another one in that did not blow out. Thanks for the help.
Did you just swap the coils? Or did you actually remove the stems from the control valve body and swap them?
Just the coils. Is there pressure to relieve under the stems?
Not sure which coil is energized when pressing the aux button to the left.
Do people start up the machine with seat bar down and bics activated while the cab is tipped open? Sorry for the question, but seems like no other way to test the parts.
Yes, those of us who work on Bobcat machines do it all the time, but just for safety reasons make sure you flip the Parking Brake rocker switch to apply the brake. Other post, doesn't matter which coil works which function since you swapped the coils and the problem didn't change. For that reason it's doubtful that the problem is electrical inputs because, as Crewchief stated in an earlier post, the Bobcat BICS system typically picks up on electrical control problems and throws a fault. Granted, that's not 100%, there are anomalies, but they're pretty spot on with electrical faults. Myself, I'd remove the stems and swap them at this point. If the machine has been idle for a period the pressure under the stems would be minimal. BTW, just to clarify and be sure, at any point in operating the machine do you ever hear three short beeps from the alarm? I have to ask just so I know we're on the same page when it comes to electrical faults.
Will swap stems. No beeps heard. No fault reads "none" and machine has an apparent splice added to a wire by a previous owner. Trying to upload a photo.
The reason I asked if you ever hear three short beeps from the alarm is that's the way the BICS system alerts you to a fault. This is important because the Bobcat system is not like typical automotive systems, like OBED II, the Bobcat system does not "store fault codes", they only work with "active codes", faults that happen "at that moment". Once you turn off the machine everything resets. Even if you had an event that would throw a code it resets when you shut the machine off. If that wire is a splice to ground one of the coils, not sure what's going on there. Again, if there was a problem with the wiring the BICS system should notice an "open circuit". But again, it's not 100%, just damn close. But according to the diagrams I look at the ground for those coils go to frame anyway, not return to main controller. Have you verified that wire is actually making a good ground? As for finding which aux spool is not working, you know that one works and one doesn't, left/right operation of paddle switch. Simple, remove one coil from one of the stems, operate circuit. If you get the "one side works and one doesn't" still, then you know it's the opposite coil/stem.
Got my stems both out. Seem froze up. Parts don't move. Also determined the coils work, as I had the machine running and coil nuts removed, to feel the coil magnetism pulls both coils down. I did not swap stems. Both seem jammed up. Nothing moves inside the stem body.
Got this diagram today for the 883G control valve body. My stems are #58 and coils are #57 but not showing clearly if there is another moving part beneath the stem inside the casting. These stems don't appear to have any spring loaded part. Wondering if the moving part lives inside the hollowed out bottom of the stem.
No beeps happening. Thanks for detailing the way the system clears itself.
I was able to free the stuck stems using a bent paperclip to stick up inside the bottom of each stem to work the brass sleeve and spring mechanisms a lot. They were really jammed up. Then reinstalled the stems and coils. Then got flow both directions on the pwm. Yayy! Then the RPMs were too low, the engine stalled while exercising the valves. Now the exhaust pipe pours out black smoke and machine won't restart. Now to hurry up and wait. Yikes!
The spliced wire discussed above, is not related to the solenoid/stems, only nearby, and it has continuity to the connectors that it's spliced into. The splice was added as a unit backup alarm. Going in reverse sounds an alarm.
Posted another thread regarding the engine stall at low rpm. Stuck with a down machine now. Pours out black smoke while cranking. No fuses are bad. Fuel primer squeeze ball is solid.
Sounds like you have some extremely sticky valve spools, you may end up having to replacing them for them to work properly. Those type of proportional solenoid valves don't just get a variable voltage signal from the main controller, they get a Pulse Width Modulation signal, basically works in an oscillation of pulses of full voltage on / voltage off/ full voltage on / off, this causes the spool to work in a harmonic vibration to help prevent sticking and give smooth action of the shifting spool, the duration of full voltage on / off determines how far the spool moves thereby giving you proportional control of the valve output.
All day down. My bad. Going to swap aux stems back to original, in hopes the engine will be under no load. Service advisor at nearest dealer thinks the jammed stem on the aux return line is keeping the engine load too high. If I get it running, gonna have to spend 300+ on a set of stems.
The engine load is most likely one of the aux spools now stuck on. Quick remedy, if you have quick couplers for the attachment connection up front, is to make a jumper hose at the quick couplers to allow oil to flow through the auxiliary circuit.
What kind of shape is the hydraulic oil? Is it contaminated by water? Or possibly was in the past and has since been flushed out and replaced. Water in oil will cause corrosion of valve spools such as these and cause problematic operation
Removed both stems. Both brass spool sleeves and springs are moving as freely now as they did earlier once I unstuck them using a big paperclip bent as a o-ring hook. I put the stems back. Left the coils off. Engine no run. Seems to be getting no fuel, yet huffing heavy black smoke upon cranking. Sqeeze ball is tight with fuel pressure. Then put coils back, sets of originals as found initially. Will try to make a QD hose to allow fluid flow through the circuit. Overnight sitting should cool off enough to get glowplugs to cycle. Sunshine has been hitting the back side all day. Kind of stuck out here in central wyoming, hours from civilization.
The hydraulic fluid went low today after working with stems. I see an orange glob floating by the sight- glass. Thanks Willie and Crewchief for hangin' in here w/ me.
Maybe not related to today's engine load and hydraulic pressure, but I've noticed another broken part - seen in the lower right corner of this photo, there is supposed to be a spring-loaded switch with a roller wheel. Present and working is the switch for the right lever. Broken and missing is the roller switch for the left lever. I've been hearing the slightest pressure flowing on the left side as long as I've used this 883G. When the left lever centers, the switch isn't being pressed.
Those are micro switches used to activate the back up alarm
Got the machine to start right up and run great today after I put a host (with all the right fittings, etc) across the auxiliary QD in/out ports. Then discovered that once I flow fluid either direction, that AUX fluid pressure is remaining constant and dragging down engine speed. Moving lots of fluid very fast. I take it this is bad for the main pump. I've degraded the situation, these past two days, because before swapping original H1 & H3 solenoids and stems (as a test, using all original O-rings, etc.) the engine ran, and machine was usable for bucket and fork jobs. Seems I've still got one or both stems jammed in a place now where fluid flows under pressure and is not controllable anymore. Somehow the flow is constant right as I turn the key to start the engine. I think I had better leave the machine off until new stems arrive, etc. Can anybody suggest a work around to get the AUX fluid circuit back into a "neutral" no pressure condition so I can run safely without having to jumper hose across the AUX QD's? Perhaps there's a spool stuck too, inside the control valve. I better not take anything else apart without at least new o-rings and seals on hand.
A pair of new solenoid stems resolved the entire problem. Nice to be able to use attachments! I learned a lot about 883G during all of this.
Indeed, good to hear you got it sorted out