I bought a used Cat304CR NAD02115. I knew almost nothing about excavators when I bought it. I did try to raise the cab using the boom and blade but it wouldn’t do it. The guy I bought it from said that’s normal but then saw videoed online where the excavator same excavator can raise the cab off the ground using the boom and blade. Also, when digging stumps, I feel it should have more power but don’t have the expertise to say for sure. Engine runs and sounds good and engine doesn't bog down when I run it hard. How should I go about investigating low hydro power? I’ve heard about checking relief valves and of course the pump could be clapped out. Any suggestions on what to check and in which order?
Attached are a series of performance tests and pressure tests. I would suggest that you carry out the performance tests first, followed by measurements of the pressures but not to attempt adjusting anytihng at this time, simply report your results.
Always so helpful Nige. Thanks. Not sure where you live but I’ll say Happy Thanksgiving anyway.
Also, it will be just after Christmas before I can test all this out. I’ll do as you say and post the result when I get back to the land I’m clearing.
I’m reading it all to make sure I understand and have all I need. In the Performance test it says the following and I’m not sure I have that. Note: The engine speed and/or the machine configuration that is used during this test can affect the results of this test. Refer to Testing and Adjusting, "Engine Performance - Test (Engine Speed)" for the engine speed that was used for this test. Refer to Testing and Adjusting, "Operational Checks" for the machine configurations that were used for this test.
I didn't include it earlier because I wasn't sure if you had a phototach to measure engine speed.
Definitely don’t have one of those and see even on eBay, they are expensive.
On this picture, I’m having trouble identifying #3 on my machine. Luckily I have a picture from when I was there of this same area. On my machine there seems to be a hose connected where in their picture, they call it a tap. View attachment IMG_0260.jpeg
Where does the hose run to? Could it be that an aftermarket quick coupler is installed and they've taken main pump pressure from this port?
Thanks for replying Chrisso. I had already left out of town when I saw this message so I didn't have a chance to look but will soon. When I got to the machine, I just noticed the test port on my machine pointed upwards and the hose pointed towards me. I used the port that was in the same location but pointing upwards.
Nige: I just got back from doing all the tests. I could not do all of them because I really would have needed someone else there to do some with me. I'm posting results now. By the way, all tests were done at full throttle.
Great work regarding the tests. Was machine at operating temperature when you took the pressures? If not you need to warm it up then recheck that pilot pressure especially. Tracking around is the easiest way to warm it up. Engine speed becomes important too. If engine isn't spinning fast enough that pilot pump wont be either.
Yes. I actually used the machine for about an hour before doing these tests. I do have an issue with my auxiliary pilot pedal. Sometimes when I start it, many controls (travel and stick at least) drop to less than half of travel speed. I learned if I turn the machine off, hold my foot on the pedal closest to me, start the engine, release the clock out, it will jump into a state that allows normal speeds and operation. I definitely have one or both of the pedal valves locked up as the pedal moves freely back and forth as though the pins that activate are seized. Same thing happened ion my boom swing pedal a while back but was able to clean it up and get it to work. I think I put one extra shim to the wrong side though because left to right movement of the boom swing is really slow and I have to press my foot down really hard to make it move at a reasonable speed.
Oh, and I’ve never hooked up my thumb I got with the machine yet because I’m digging stumps and don’t want the thumb in the way.
Ok. I think if one or more of those pedal valves are sticking and/or dumping pilot to tank that would give you all sorts of issues including low implement speed and low pilot pressure. P/n for that valve is 162-4578. I can't see any seal kits available but some individual parts are, including a whole new valve assembly. Without that valve working properly I don't think you could properly diagnose anything with the pilot system. I mean you could cap that pedal valve off completely and recheck pilot pressure, but that's just putting off the inevitable i think. Second thing I would inspect is the pilot relief. This is covered in the docs Nige posted. I would at least inspect for damaged seals, springs, shims etc. I would not recommend adjusting anything until you: 1) verify engine speed. 2) repair the parts of the pilot system you know are faulty (ie aux pedal pilot valve). Third biggie is inspecting the hydraulic filter for debris. Has this been cut open and inspected yet? Hope that helps.
Keeping in mind, you could spend a few grand and get the pilot system working properly and find the main pump is worn out. I had a similar machine a few years ago where all cycle times and relief pressures were in spec, but machine just wouldn't dig or travel up hills. Problem could only be diagnosed by flow testing the main pump. Just letting you know what may lie ahead
I was able to go to my land and bring the aux pedal back with me. When I disassembled it, the shims on top of the pistons were mangled as though they never put it back together correctly. Probably why I’ve always had issues with it. Also, one of the little piston shaft holes had an obstruction in it. Where did you see parts for these? I only see the full pedal assembly.
I found the parts on SIS