I recently purchased an Erskine snowblower requiring 22-24gph. The blower is new and Erskine has helped me troubleshoot and does not feel the problem is in their unit. I am attempting to use it on a CAT 287B (ZSA01404) which does not have high flow hydraulics but the book says is rated at 22gph at fast idle. When the aux control roller switch is activated (with or without continuous flow) the auger and fan only turn an estimated 20-30rpm. The fan is supposed to turn 630 and the auger 240rpm. All of the wiring to the external auxiliary connections have been tested an energize with control inputs as they should. All of the fuses and relays are patent. I suspected the auxiliary hydraulic solenoid valve so I removed it and hooked 12v to it and the valve actuates. I don’t have a hydraulic system schematic, but was surprised that hydraulic oil flowed freely out of the port where the valve was removed. Is this an indication that the spool is stuck? Anyone have advice on how to proceed? Thanks!!
You should do this carefully but try applying 12v to the relevant AUX solenoid valve with it installed in the control valve and with the engine at maximum RPM. Observe the results at the snowblower. TBH i would not have thought it possible a 20+ year-old MTL machine would today be producing anywhere near what the book says as regards hydraulic system flow output. That is illogical. I would say that you need a machine with High Flow to run that snow blower. Check your message inbox for a hydraulic schematic.
Thank you for the schematic Nigel. We have two of these machines of the same vintage and are running the same model snowblower with the other machine, so I assumed I could use a blower with the same flow required on this machine. I tied your suggestion and when the solenoid valve is energized with a 12v battery it produced the same result at the blower. I believe the next step is to measure the actual flow but I am 250 miles on icy roads from a dealer and no one in my community repairs CATs. The local hydraulic shop has a flow meter, but they don’t know where to test on the control valve. Can anyone offer some guidance?
Actually you may be able to get a good idea of the hydraulic system performance using a stopwatch. Get the oil up to normal operating temperature and try the testing cycle times shown in the table below. The centre column for the lift cylinder contains the cycle time target for a 287B Standard Flow machine. The RH column is for High Flow.
Is the other machine High Flow or Standard.? Serial Number.? Maybe compare the cycle times between the two machines.
My other machine is ZSA01372 with standard hydraulics. I was not aware that there would be a relationship between the lift cylinders cycle time and the auxiliary (work tool) hydraulic pump flow, so thank you for the insight.
On a STD machine a single gear-type pump supplies all the oil for both the implements and the AUX function. On a High Flow machine the gear pump of the Std machine is replaced by a variable displacement piston pump to provide additional flow for both the main implement system and the AUX function. That is why on the HF machine the target implement function cycle times are faster.
The travel times for the lift and tilt cylinders for two machines (with the blowers attached) are within .1 seconds of each other. I replaced one aux solenoid valve coil as it was badly rusted and seemed to make a weak click when 12v applied. Now when I try running the blower with 12v direct to the solenoid, the blower operates as it should. It cannot, however be operated using the thumb roller switch. I am attempting remove the floorboard to perform testing Nige recommended in another thread, but would appreciate some guidance on how to get it out from someone who has done it. Thanks!
That statement leaves a question hanging over the AUX input from the thumbwheel roller switch. Locate Pins 1, 2, & 3 of the 12-pin connector directly under the joystick. 1. With the key ON you should have 8.0 +/- 0.5v between Pins 1 & 2 if you back probe them. 2. With the key ON measure the voltage between Pins 2 & 3 with the thumb roller in the centre, again by back probing. Then roll it all the way in one direction and measure the voltage. Lastly roll it all the way the other way and measure the voltage. Report your results. If an electrical schematic would help you then please ask.
That tells me there is nothing wrong with the pump output, so it must be down to the control side. Have you ever fitted an attachment to this machine before that used the AUX function.? If you have did it operate OK.?
Yes, I had a snow plow with a two way blade. It worked, but went really fast to the right tilt and slow to the left tilt. Do you have any advice on how to remove the floorboard? I have all the bolts out and the throttle pedal loose, c-clip is off, but the arm will only come off 75% of the way in the available room.
That would have been useful information to have had earlier. Sorry, no idea. Never had to do it.
Roller switch centered 4.11v back 5.24v forward 3.39v
8v to pins 1-2
Therein lies your problem, or at least I think so. A switch in good condition should give around 1.8v of difference when rolled from the centre to either extremity. So your targets should be 5.9v and 2.3v. You’re nowhere near that. Can you try swapping in the RH joystick handle from the other machine and see what results you get.
Unfortunately, the other machine is 300 miles away, So swapping is not possible. It was easy to have someone measure the lift and tilt times long distance, but not so much for swapping. I am a little confused as I looked at a post from 6/24/2023 where the poster was told normal was 4.5-5v when centered and about .8v variation forward and back. I thought I had seen a post about a replacement switch, but I have searched and cannot find it. Do you recall what it was?
I think this thread may give you a few answers as to what’s going on with your machine. It appears that the voltage change on a working switch can be as high as +/- 2.5v from the centre position. Cat 226b thumb wheel switch replacement Has anyone found an aftermarket thumb wheel switch that works on a cat 226b skid steer it's on the right joystick . Mine has gone completely missing and the replacement is cost too much. Is there any alternative switch that can work in its place to get the auxiliary working again. Even the the... HeavyEquipmentForums For a machine such as yours that uses a Hall Effect switch no suitable aftermarket replacement switch was ever identified. The thread I linked also discusses that.
Thank you for all the assistance in troubleshooting my problem. While I attempt to fix the switch or get a new joystick, I am considering running 12v power from the “spare” in the fuse block through a seat or door safety switch to a toggle switch hooked directly to the aux solenoid valve. This would allow me to use the blower while I come up with a solution to the thumb roller.