Caterpillar 287 need help with hydraulics- machine moves very slow

[jreese7290]

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?

 

[92U 3406]

Cut open old filter. Hydraulic level correct?

Check charge pressure.

S/N would help get you proper information in terms of pressure specs.

 

[jreese7290]

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

 

[Nige]

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.

 

[jreese7290]

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.

 

[Mobiltech]

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.

 

[jreese7290]

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?

 

[92U 3406]

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.

 

[jreese7290]

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?

 

[Nige]

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.

 

[jreese7290]

Thanks everyone for your input im going to test further when i get home

 

[jreese7290]

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...

 

[jreese7290]

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.

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...

 

[Nige]

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.

 

[Vetech63]

The pressure did not stay steady when you try to drive forward the charge pressure fluctuates goes up then back to 0.

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.

 

[92U 3406]

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.

 

[Nige]

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.

 

[92U 3406]

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.

View attachment 209589

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.

 

[jreese7290]

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?

 

[Nige]

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.