Hello, 2007 cat 312c serial number 6LK24531 (grey market?) 6000 hours, Was operating and thumb was working, then the thumb would only extend and not retract. I swapped the hoses on foot pedal to check the foot pedal valve and it did same thing just with different direction of that control valve. I’m thinking it may be the auxiliary valve / solenoid. The part comes back at costing $3400 from the dealer. Anything else i might be missing, or any other things to test? The machine has auto idle and the machine will still idle up when the retract thumb function is used, but no other reaction from the machine, no dead head or motion in the thumb or hoses.
That's the engine Serial Number. The machine is CAE00297 and yes it is grey market. For parts and service information you could use the CBA-prefix for which all information is available. Hopefully someone else can help you with your hydraulic issue. What is the Part Number.?
165-9560 is the part number
Thanks for the info. I will have to pull the actual machine serial number off of it soon. I got that serial number off the invoice. I’ve had the machine a couple years and put 600 hours on it. It has been a good machine. Just trying to get the issue diagnosis correct before I go throwing non-returnable parts at it
There is a some lower level part associated with that 165-9560 Part Number. 1 x 197-0251 Valve Gp, Solenoid, illustrated below. 165-9560 as a complete unit is cancelled and replaced by 201-9367, then by 215-4680, and finally by 297-0370. Parts breakdown attached. Dunno if any of that info helps you.
Yes thank you that does help. I was wondering if that solenoid was replaceable or if I had to replace the whole valve. A quick search for that part number shows it’s only $194 and available aftermarket. I was hoping for guidance on how to remove or test that solenoid part to confirm that’s what it is not functioning.
Have you tied applying battery voltage (24v I assume) direct to the connector on the solenoid.?
I have not tried that. Yes it is a 24v system the batteries are cross wired. How could I get 24v to that, run leads from the batteries? I would assume if I applied the voltage to the connector I would hear a click and then that would verify that solenoid is still functional. No noise then the solenoid/ check valve is bad there
Im confused why you're looking at attachment valve solenoids if your attachment valve is pilot operated off the foot pedal?
i just traced the hoses back from the thumb up the boom and it was the first part I hit. I checked the foot pedal to make sure it was doing what it was supposed to, so I’m just going to the next part in line after that pedal. The hoses come off from the thumb and go back to the two valves next to the cab with hoses coming off them, I assume that’s where the foot pedal pilot hoses are going to to operate the valves and therefore the thumb / attachment?
Do you have a pic of the valve? Sorry, I'm not trying to confuse anything or send you down the garden path, I'm just trying to wrap my brain around what you've got there. Usually your thumb is run directly off your attachment spool, which would be pilot operated directly off your foot pedal, so should be really simple. Out of curiosity, is the thumb even trying to retract? Like if you hold retract on the pedal will the thumb come back with gravity or pull back using the bucket? And if you sit there and just cycle retract on and off, can you feel the pump stroking up? Also, FFF2 should get you into service mode in your monitor. Id be playing with watching p1 and p2 pressures while you activate the thumb in both directions.
I can try to get some photos of it this week. Yes the foot pedal has pilot hoses that are running to two separate valves with solenoids that have hoses going back to main pump and then out to the metal boom hydraulic lines and finally to the thumb. The thumb doesn’t do anything at all when the retract function is engaged. The only thing that changed is that the engine will throttle up out of the auto- idle that it does when you don’t use any controls for a bit. I’ll check out the service mode next time I go to mess with it. I guess I can try to jump the solenoid on the auxiliary valve to see if that solenoid is dead
You must have two of everything on your aux valve? If so, and if you can, instead of jumping power from the batteries, just try swapping parts around. You can swap your two pilot lines, swap the two solenoids, and if you have enough length swap the connectors on the two coils. Im curious what you've got, ill fire up SIS tomorrow and see if that valve is shown.
That’s good thinking. I’ll get a couple photos posted tomorrow. Thanks have a good evening
No sweat, you too
So here’s where I’m at. I swapped connectors, same result, swapped solenoid magnets, same result. Now I’m at the valve / spool I guess. A little confused at removing this part. I guess it must be a special tool or else I need a puller?
Ok, those are the variable reliefs for your tool program. Can you go into the tool program and confirm your in thumb, shear or some other double acting tool, and not in hammer or hoe pack?
Did you eliminate the cylinder piston coming off the rod?
No I haven’t tested the cylinder yet. I tried to swap those hoses but they are not long enough. Any ideas on how to test that cylinder? The working hose has a big bubble in it but not broken yet
If you've got no test equipment the easiest way to text the cylinder is probably to plug the 2 lines going out to it and see if the pump loads up when you hit thumb in both directions.
I did check the tool program. It has always been in “aux tool 1” and worked. I switched to bucket / no tool and it still acted just the same. I put it back on “aux tool 1” and left it
You should have a few other symptoms if the piston has come off the rod though. Like the thumb creeping, and you should be able to extend it by pulling on the thumb. You should also be able to hear/feel the pump stroking up when you try to retract, even if theres no movement. You'll also see it if youre monitoring discharge pressure in the display
Well the thumb has 2 manual shut offs and I had shut both sides of it and tried both functions and no reaction from the thumb retract function, so I think that would be the same test? So in summary I have eliminated the foot pedal, the connectors, the solenoids, and I pulled out the one valve to look for debris and replaced it and ran the machine and no change in the issue. The cylinder doesn’t hold and pressure at all, If I use the bucket to curl the cylinder back in it wil just drop back down with gravity. Again the extend seems to work fine, it’s the retract function that’s toast. I’m thinking next I might swap the valves to see if it is somehow the internal workings of the valve? I’m not sure what else is involved in this connection. I checked both the “aux circuit” fuses and they seemed fine. Only other thing that seems strange is the hydraulic hose on the working function side has a if bubble in it. Picture
So with your ball valves shut, it loads the pump if you try ti extend, and no load if you retract?
Yes that is correct. I push retract and only thing that happens is engine will auto idle up if I have let it idle down. Otherwise no dead head, pump noise, hose movement, nothing.
Have you got the work tool flow mode control switch in your panel?
It just says select tool and there’s like aux tool 1-5 and a bucket / no tool option. I haven’t really dig into that much, I will look again at it next time I’m back there. I think it has to be a component failure because it stopped working while I was operating it. There is a thumb Bhutto on right joystick that sounds like it would be for a hammer tool and I push it and made some noise but doesn’t change anything.
I see what you mean, There are some switches there on the side, I will have a look at them. Could be a flow mode switch there that got bumped somehow
Ya, if that single/double action switch got bumped your thumb will only work in one direction. If its a hyd issue, its odd that the thumb wont come down with gravity when you hold the function. If either the variable relief or circuit relief was failed, the thumb should still come back but be slow and weak. You can probably eliminate the variable reliefs by plugging iff the -12 return lines off both valves. The circuit reliefs are easiest to just swap top and bottom. It could be an electric issue off that switch. If you haven't already, you might want to bring out a test light and check all your fuses too
I just stopped into the machine and found that switch you were talking about. It must have gotten hit by my chainsaw helmet or elbow or something I didn’t know it existed. I hit the switch and the thumb came back to life. Thanks for the help. I’m a dummy but at least it is solved and it only cost me some pride
Ha! Easy fixes are the best fixes
Feel free to send me the $3,400 usd you were going to spend on the valve