I have a client that has a Caterpillar 289D with 5000 hours. Equipment starts good no problem, but that Equipment won't move anything, no loft arms move, no bucket move neither drive motors either way forward or reverse. no codes on screen. I hooked my Cat ET and doesn't show any active codes no events. Parking break works fine, also Hydraulics break works fine both commands works fine but won't do anything. I check a Parking break solenoid and shows 7.3ohms through the coil. According to manual said that coil should has 75ohms resistance. now is that any missing procedure on troubleshooting on this problem that I have to check? Help me get this figured out. TIA.
This needs two people. Have one watch the cooling fan in the back while the other starts the engine. Does the fan start turning immediately the engine fires up.?
check your charge pressure
It’s the last pump on Hyd stack if you have no charge pressure then the coupling is probably broke between engine. Or like comment above said check your fan it also runs the fan. If that’s not turning then likely you have a failed coupler
Fan doesn't start at all when start up equipment. Also, this radiator whent first look at it, was bone dry. My client said that was beeping and make sense because on CAT ET on logged events was high coolant temp and high overheating temp alarm logged in pass. We do top it off radiator yesterday with new coolant and nothing happens.
How can I check charge pressure on that gear pump.? We have Hyd pressure gauges, but not sure where hooke it up to check pressure. Please could help?
The coupling between the engine and the hydraulic pumps has failed. Time to pull the engine...........
Coupling is good, no broke. Have you know how to check charge pressure on that pump?
How can you say that.? You can't even see the coupling unless the engine is separated from the pump group.
Cause, they already separate engine and pump.
Thanks for telling us. That information might have been useful to know at the start.
Yep
Broken shaft inside the hystat pump.?
Not sure cause, I'm not breaking apart that pump yet. I suspected on parking break solenoid. I measure 4.5ohms. And manual said should have 75ohms resistance.
The problem is that the cooling fan is not turning. That indicates no oil flow in the implement hydraulic system. The first thought is a failed coupling, but if that is OK and the machine has no drive or implements then it sounds like something in the hystat pump could be broken, because that pump drives the implement hydraulic pump which is on the opposite side of it to the engine.
Okay I will look at in the pump.
Change the drive coupling while it's apart, I've seen them start to deteriorate at around the 3,000 mark. If it's the original with 5,000 hours it's probably getting close to the end of its reliable life.
Okay
I’ve come across it once before where the coupling was not failed but the hub of the coupling had come loose and had slid down the shaft just far enough to disengage it from the splines. Is there any chance that has happened in this case.?
I will look it up for you. But there has to be a test port somewhere. So is the pump now out of the machine. If so I wouldn’t take it apart just yet. There’s a lot in those and if you mess it up then it’s a lot to repair it. Is there a quick connect on fan drive itself.
I mean it’s possible you are loosing all your charge flow through the hst you can be losing it through the drive motors it could be a complete separate issue. But when ever a hydrostatic machine doesn’t move the or no functions work you check charge psi
Appreciate any help, with troubleshooting or procedures to test that pump. And where hook my pressure gauge.
IIRC oil flows directly from the charge pump to the fan and then from the fan outlet to the rest of the system. What's downstream of the fan is more or less irrelevant at this point if the fan is not turning. OP needs to verify that the charge pump is actually moving fluid before moving on.
Attached some information on testing of pressures plus pressure specifications. What is the status of the machine right now.? If the pump stack was removed has it been replaced.? Can the pressures be tested.? As per the recommendation of @92U 3406 I would also suggest that the coupling be replaced while everything is disassembled.if the machine already has 5k operating hours.
As I suspect, there's no pressure at all on that Hstatic pump neither on hyd.fan motor. Checking with Cat ET Hyd oil temperature all the time been on 84°F. Charge pressure port 0-psi. Front and rear roating group on Hydstatic pump ports 0-psi. Fam Hyd. Motor port 0-psi. All solenoid in hydraulic system are getting signal from joysticks command.
Are you SURE that the pump coupling has not slipped sideways on the shaft as I mentioned earlier.?
Today I will disassemble pump from engine and check that out. Keep u posted
My memory's a bit foggy but I don't believe there is (or was) a coupling attached to the pump shaft. The pumps splined directly into the coupler bolted to the flywheel. It's been nearly 6 years since I've had one apart last so I could be mistaken.
I could have sworn we had a case (but can't find the thread now) of a late-model Cat SSL where the coupling slid sideways and effectively disconnected to the drive.
Coupling is not meeting the drive shaft of the pump. It's out abut 1inch. Now, how it's that happen? How could I fix that big gap between those 2?
Can you post some photos please. Also does the coupling gave a “right” and “wrong” way of installing.? In other words could it be installed backwards.?
During all this repair work has the coupling on the back side of the engine ever been removed.?
What coupling? Is other coupling?
By "coupling" I am referring to the disc mounted on the back side of the engine flywheel. #1 in the illustration below. This is the one that @92U 3406 was recommending you to replace because the machine has 5000 operating hours. They are well known for failing. Can you also confirm that the coupling #1 is plastic.
Yes it is like black plastic. I'm trying attached pictures from my camera but picture format is not valid. Let me try again.
During all your repair work has that coupling ever been removed from the engine flywheel.? The reason I ask is that it is clear from your photo the internal splines (red arrow) in the coupling hub stop well short of the end of the hub. Could you possibly remove the coupling and inspect the other side of the hub to check if the splines come right to the end.? If they do then the coupling has somehow been installed backwards.
Yes it does come to the end because I check with my finger. And yes the other mechanic remove that coupling off flywheel.
In that case i suggest that you try reversing the coupling and see if you can get it to mate with the pump input shaft.
There is the problem. Splines on old coupling are worn and Splines on new one are all the wat end to end in drive side bushing as pictures shows.
Ah. So in that case go back to Post #7 on Page 1 where I said that the coupling had failed.
Correct. Meanwhile parts been ordered to get this job done done. Appreciate alot all you help. Thnks.
looks stripped compared to this picture
Ouch.....
Coupling installed without pull engine out of equipment. Around 3.5 hours task.
Small things count when doing a job like this one. For example the coloured zip ties for identifying hose connections. Well done.
Paint marker works well & pictures.