I have a caterpillar 287 and for some reason while working today the machine will only move very slowly. The 2 speed kicks in for about 1 or seconds then the machine just barely moves. When you rev the motor up in higher rpms it sounds like there’s air in the system and there is a high pitched Whining noise. I have checked hydraulic fluid and change the hydro filter. My next step is to look at the 2 speed piston gear pump attached to the main pump. Do you all have any other suggestions?
Cut open old filter. Hydraulic level correct? Check charge pressure. S/N would help get you proper information in terms of pressure specs.
My serial # Cat00287pcny00372* Can anybody help me with the procedure to test hydraulic pumps to confirm I have the correct pressure’s in the system
Have you changed the hydraulic system filter and cut open the old one to inspect for the presence of particles (that would indicate pump issues) as a first step..? Filter P/N is 1G-8878. Do that first and post photos of whatever you may find. If the filter cut proves inconclusive then it's time to go pressure-testing. I can supply the test procedure at that point.
I have cut the filter open and I didn’t see anything out of the ordinary the fluid was clean. i will get you pictures later I’m not at home. Can you provide me with procedure to test both pumps. I have the main pump and then the 2nd smaller gear pump in front which I think controls the 2 speed hydraulics. Is that right? I bought a set of hydraulic gauges but I’m not sure what I’m looking for. I have 3 test ports on main pump and then 1 on the control valve and I saw another back of engine at hydraulic filter.
Is the cooling fan running a good speed? The hydraulic pump closest to you when you lift the cab is the implement pump. You shouldn’t have 2 speed implement just 2 speed travel if it has that option. Make sure the tank is full.
What exactly does the 2nd pump closest to the front cab do? What's its purpose?
Should be your charge pump. The next one closer to the engine should be implement and the big sucker bolted right to the engine is your drive pump.
wow so in Caterpillars infinite wisdom. They designed this machine with 3 separate pumps. What is the procedure to test the pumps to determine if one is bad?
Well it's a pilot-operated system so unless the pilot pressure was produced by a pressure reducing system from the main pump then it's going to have at least two sections on the gear-type implement pump - pilot & main. The 2-section piston pump is for the travel function. Here's the Hydraulic Schematic and the procedures for testing pilot pressure and main relief pressure.
Thanks everyone for your input im going to test further when i get home
If I did the test correctly I don’t think pilot pressure is correct and in need to proceed to Testing and Adjusting, "HydrostaticSystem - Test and Adjust". The pressure did not stay steady when you try to drive forward the charge pressure fluctuates goes up then back to 0. I also cut the filter open. I have no metal shavings what so ever in the filter. At most the filter had some grime and dirt...
Maybe Without realising it you've hit on something key. Hydraulic systems are supposed to be clean. What would happen if some of the "grime or dirt" has become wedged in a control valve somewhere.? I think you're in for a full system cleanout, starting with removing the tank and steam cleaning it, followed by the rest of the system. For confirmation of that, post a photo of what you found in the pleats of the hydraulic filter.
That is usually a leak in the high pressure side of the system that causes the charge pressure to drop. The design of those pumps is funky to me. I had a 299 that lost a swash plate slipper in the second hydro pump, and because the design was to have a common suction port with the pilot (gear) pump, the gear pump sucked in the brass and trashed the fan drive motor and all the evidence was in the return filter.
Sure it was a return filter? Every Cat skid steer I've touched just has an inlet strainer and high pressure filter in the charge circuit between the fan motor and hystat pumps.
Only filter indicated in both the Parts Manual and the Hydraulic Schematic for the S/N given is in the return line - 1G-8878. This is a 2003-built "A" model machine. Just looked at one of our recent D models and it has a high-pressure filter mounted in the charge circuit.
I was responding to vetech's comment about the 299. Definitely interesting to know, thank you for the info! Very rare for us to see C model machines around here these days. Everybody runs the new D models.
Just a shot in the dark i want to change the hydraulic oil on the 287 Cat. What is the exact replacement i should use. Can i purchase it from an auto parts store?
If you want to flush the system with it, no reason not to buy from the auto parts store. Fluids of that origin are known as "Joe Blow's Gas & Groceries" products on HEF - not well thought of in the professional fraternity. You should be using an SAE10 viscosity (ISO32) anti-wear hydraulic oil. If you are planning on draining the old oil and refilling the system with new oil I suggest you buy something with a major oil company brand label on it. Something like Shell, Mobil, Conoco, etc. However please go back and to my post #14 above. I strongly suspect that you have a contaminated system. Changing the oil is not going to fix it.
So was I right? Hell, I've seen way to much equipment since that job. I seem to remember the pump outlet line going straight to the fan motor. The return line from the fan motor to the return filter mounted at the top left of the engine compartment. I might be thinking of another machine...…...it sucks losing brain power as you get older.
I ended up paying for a Caterpillar technician to come out. He concluded it was either the joystick ($1300) or total pump failure ($6000). I replaced the joystick 1st with an oem Caterpillar unit and that did nor change the issue. Now im looking at replacing the pump. Can anyone send me the repair steps for the pump. I am curious to know how extensive the piston pump replacement will be and if its something i can do myself without pulling the entire engine.
That’s some good troubleshooting it’s either the joystick or the pump. Wow. Pump replacement is done without pulling the engine. BUT. I would sure want to do some more testing before I threw a pump at it. If the pump failed what about motors? I would be calling the cat dealer you dealt with and tell him to send out someone who knows how to troubleshoot a hydrostatic system.
Wot he said.......... double.
We tested the charge pressure and it was extremely low. The reason the technician said it may be in the joystick is because when you move left or right the hydraulic gauge still reads 0. It seems like there is no pressure when you turn the joystick left or right. The machine will move forward and backwards just not at full power. Also there is a very noticeable whining noise when you have throttle on high coming from the hydraulic almost sounds like air is passing through internally.
Low charge pressure I'd be looking at the charge circuit first. Charge pressure will directly effect hydraulic performance.
I’m getting confused. Is the charge pressure low or zero regardless? Or just low when you try to steer? Something isn’t making sense to me.
Proper testing by a qualified mechanic should narrow it down to a charge pump problem, an internal leak in the pumps or motors or a leak at a charge relief valve.
Find a competent tech to troubleshoot. There are very few issues that require part replacement as part of the diagnostic procedure.
It could be this, this, or this. I know, let's replace the cheapest one. Then if that doesn't work replace the next expensive one on the list, etc, etc. Continue the process until something is replaced and the problem goes away. It's called fault finding by substitution.
That rich people fixing.
Can anyone send me the install guide for a caterpillar 287
Is charge pre OK Cat guys! What else is on the charge circuit? Is fan on charge or implement circuit?
For charge pressure to go to 0 that hydrostatic pump would have to pretty much dead! Not slow!
In event of low pilot pressure it could be internally bypassing joystick or internally bypassing servo piston inside the pump! So looks like (indirectly) Cat man detected low PILOT pressure! Here’s very important question: are we talking pilot pressure going to 0, or we are talking charge pressure going to 0?!?!
Looks like hydrostatics are Rexroth A22VG series 10.
Very first post talked about high pitch noise like air in the system - first thing in this case to inspect suction strainer and suction pipes. Cavitation can kill your pumps really fast!
Another thing that can dump your main pressure whst do you mean by “install guide”?
What is the easiest way to flush the hydraulic system of contaminants 287b
Depending on how badly it was contaminated, anything up to complete disassembly. What broke in your case.?
We just did a couple from major failures. Something like 40+ hours worth of labour on each. Not quick, not cheap. Most components were removed and cleaned, lines pigged etc.
So the drive pump was determined to be bad I will be draining and flushing all pumps to rid of contamination. What is best way to refill fluid to all pumps to avoid starting machine dry and pumping fluid to them? and is there bleeders I need to open to bleed system of air?
If the pump is “bad” something has failed internally, such as the slipper plate. If the pump isn’t stroking up it won’t be cavitation, so the noise may not be what you think. If the strainer in the tank is clear, it’s a clear path from the tank to the pump, especially as the tank is above the pump. Have you cut the filter open yet? If there’s brass in there, chances are it is a pump failure, as the hystat and implement pumps are about the only place in the system (apart from the motors) with brass components.
As IH says, first steps - cut the filter open and look for particles in it. Take photos pf whatever you find. Next, remove the screen (#5) from the hydraulic tank and inspect for particles. Again post photos of whatever you find.
No photos but lots and lots of brass. Handfuls! Determined my hystat pump is bad. Have new, flushed system, Is there a proper way to refill system other than fluid in the tank and starting the machine to get it into all pumps
If you want the replacement pump to live I think you're going to need to do "a bit more" disassembly. Have you removed, disassembled, & cleaned: - 1. Drive motors 2. Lift & tilt cylinders 3. Control valves 4. All the hoses Because everything will be empty on the first start I suggest that you ignore the sight glass on the hydraulic tank and instead fill the tank right to the neck. When you first crank up the engine the oil will disappear from the the tank in the blink of an eye. Filling it right to the top gives you at least a bit of a head start.
To build off this, the machines we cleaned out went through a filter and a hydraulic oil change after a couple hours of running around the yard and there was still some small pieces of brass and metal in the filter. What we did: -Cleaned lift cylinders -Cleaned tilt cylinders -Removed and flushed the reservoir -Removed, disassembled and cleaned out the main implement valve -Replaced cooler -Removed, disassembled and cleaned the ride control valve -Pigged out and cleaned out dang near every line on the machine -Cleaned out pumps. -ISO particle count to verify system cleanliness We were in the neighbourhood of 40-45 hours in on each machine.
All the above - with bells on........... That's the most complete description I've seen of how to decontaminate the hydraulic system on a SSL
Can I use a Traveller iso 46 hydraulic fluid to run through my cat 287b? It says not recommended for final drives. I will be running it for a little while and then changing it to cat hydraulic fluid
Were the travel motors also disassembled?
Hard to say. There were multiple machines with the same failure. I got pulled off my machine mid-job for something else and another guy completed it. The original plan we weren't. The higher ups reviewed the schematics and determined that since charge flow goes through the filter before entering the hystat system that it was unneccessary. There was nothing in the histogram on that particular machine indicating that the filter had plugged and bypassed.