Loss of Power after Coupler Replacement

[jashford1]

Good day everyone, yawl recently assisted me troubleshooting some codes after I pulled the engine and replaced the coupler on my 2015 299D2 XHP (S/N: DX200203). Today I decided I would run out to woods where I left my John Deere MH60 mulcher when the coupler went out. I noticed a few things as I headed out.

1. I didn’t seem to have the power or speed I previously had. RPM at full throttle is showing 1863 n/min.
2. After getting in the woods and attaching the mulcher I figured I would clean a little as I made my way back to the house. As soon as I engaged the mulcher the skid steer speed dropped to zero forward motion. Turn the mulcher off and I’m going again. When engaging the mulcher the rpm drops to ~1200 then climbs back to the original 1863 n/min.

What am I missing? Prior to me spinning the coupler everything was fine. Thanks

 

[jashford1]

UPDATE: I changed the inline fuel filter today and it is better but continues to drag down when using any power. Sitting still, at full throttle it runs about ~2500 rpm. If I engage the mulcher, it bogs the system down (if I’m just idling, it will kill the engine). It even bogs down if I’m moving and raise the lift arms. I guess my next thing will be to change the fuel/water filter. I was going to change the primary air filter but local CAT dealer doesn’t have one in stock. I think I will remove the primary filter, start the engine, and engage the mulcher in place as a test if I’m getting enough air. I am assuming a diesel is like a gas engine on fuel and air blockage.

 

[Nige]

I would suggest to think further than just the filter elements. Consider the tank, fuel supply lines, and the fittings/passages in the head of the fuel filter/water separator. Your fuel lines are the same as the one on this THREAD. Same comments apply.

Also have you looked at the screen that is part of the electric fuel pump assembly. See Post #4 of the linbked thread.

 

[crane operator]

What originally went wrong, when you spun the coupler? Did you jam something with the mulcher?

I'm just wondering if you damaged something more than just the plastic coupler.

 

[jashford1]

I was mulching in small brush thicket when I lost all power.

 

[jashford1]

I would suggest to think further than just the filter elements. Consider the tank, fuel supply lines, and the fittings/passages in the head of the fuel filter/water separator. Your fuel lines are the same as the one on this THREAD. Same comments apply.

Also have you looked at the screen that is part of the electric fuel pump assembly. See Post #4 of the linbked thread.

Recap of everything and update. Serial Number DX200203, ECM HW PN 3693556-03, ECM SW PN 5836260-00. Long story short, the engine to hydraulic pump spun. I pulled the engine and changed the coupler. Got everything back together, wouldn’t start due to “E459-2 Machine Engine Rated Horsepower Output Changed Engine Power Rating Mismatch” which was the plug at the ECM not seated good. Got that straightened out and it started right up and ran fine for maybe 30 - 45 minutes then started acting like the engine was overloaded or not getting fuel or air, maximum of about 1,200 - 1,500 rpm. I replaced the inline fuel filter, that helped quite a bit, it would at least run up to 2550 rpm but would bog down when I did anything (engage mulcher, turn, raise the arms, etc.) anything but move forward or backward. I changed the fuel / water filter, I thought that was it, started up, had throttle response, it would ramp up, drivable and able to engage my mulcher, etc. etc. for about 15 - 20 minutes. Then it went to hell, bogged down and died. It will start, but won’t get up to full idle, up to about 950 rpm then dies. Cranks right back up, but same thing again, 950ish rpm, runs rough as all get out and dies. The only user events showing is E60033-2 Machine, Eng. Speed Limited Warm Up Mode because it was a little cool this morning. View User Diagnostics only has one event, it is 3700-3 Machine Loader Bucket Inclinometer Sensor Voltage Above Normal. Looked under Service, Diagnostics, View Events, there is No Active Events. Looked under Service, Diagnostics, View Logged, there is a E361-3 Machine, High Engine Coolant Temperature, and E459-2 Machine Engine Rated Horsepower Output Changed Engine Power Rating Mismatch, and E570-2, Unexpected Right Motor Forward Speed Detected Check the motor speed sensor and wiring.

 

[crane operator]

So imagine this: Something lets loose in the hydraulic pumps, you've seized the end bearing/ scored a bore, whatever. Pump gets hot, seizes the bearing, motor is still humping along, hydraulic pump stops. Now you have a stripped coupler.

So you replace the coupler, but you haven't addressed "why" the coupler stripped. Bearing is still bad in the pump, but its not hot yet, so it will still turn, limited movement, but its pulling on the engine.

You would be able to move a little until everything got hot again, and now the pump is still jacked up, and the engine can't hardly turn it. You just haven't restripped the coupler yet.

Are your pump and engine mount brackets all good. Don't have a misalignment causing things to bind?

Maybe something in a valve is stuck, deadheading hyd., making the pump almost impossible to turn, loading it and the engine up?

What do things sound like when its trying to run?

 

[jashford1]

So imagine this: Something lets loose in the hydraulic pumps, you've seized the end bearing/ scored a bore, whatever. Pump gets hot, seizes the bearing, motor is still humping along, hydraulic pump stops. Now you have a stripped coupler.

So you replace the coupler, but you haven't addressed "why" the coupler stripped. Bearing is still bad in the pump, but its not hot yet, so it will still turn, limited movement, but its pulling on the engine.

You would be able to move a little until everything got hot again, and now the pump is still jacked up, and the engine can't hardly turn it. You just haven't restripped the coupler yet.

Are your pump and engine mount brackets all good. Don't have a misalignment causing things to bind?

Maybe something in a valve is stuck, deadheading hyd., making the pump almost impossible to turn, loading it and the engine up?

What do things sound like when its trying to run?

Since the beginning of the problem, I’ve tried to figure out how to test the hydraulic pump. I’ve thought it would be simple during building to put a couple of connectors on the output side of the hydraulic pump and motor to connect a pressure gauge and check pressures, but they don’t. Until today I used the mulcher pressure gauge to see hydraulic output. Even today until the engine began it’s fluttering, missing and dieing the pressure gauge on the mulcher jumped up to 2300 psi before dropping back to 1200 - 1400 after the drum gets to speed which is normal. Now it doesn’t run long enough to do anything.

 

[Nige]

I think you could be at a point where you can’t see the wood for the trees. For example…..

I replaced the inline fuel filter, that helped quite a bit, it would at least run up to 2550 rpm but would bog down when I did anything

So there is a clue……

Go back to Post #3 above. In it there is a hyperlink (blue text) to another thread where the work on the fuel system was discussed in detail for an identical machine to yours. Do all the steps suggested in that thread - don’t skip any, before moving forward. I am reasonably confident that you’re going to find debris in the fuel system, possibly as a result of the engine R&I.

I could give you all the procedures for testing the implements and drive system but I think it would be a waste of my time and yours.

 

[jashford1]

I think you could be at a point where you can’t see the wood for the trees. For example…..

So there is a clue……

Go back to Post #3 above. In it there is a hyperlink (blue text) to another thread where the work on the fuel system was discussed in detail for an identical machine to yours. Do all the steps suggested in that thread - don’t skip any, before moving forward. I am reasonably confident that you’re going to find debris in the fuel system, possibly as a result of the engine R&I.

I could give you all the procedures for testing the implements and drive system but I think it would be a waste of my time and yours.

This will be today’s project.

The comment on testing hydraulic pressures was referring to the very beginning of this mess. Everything I read and everyone’s thoughts and suggestions was the coupler. But I could not find anything, anywhere on how to actually test it. It was all remove the engine or all of the hydraulics and hope the coupler was bad. Personally, I would have liked to test it before all of the work began, fortunately for me, I did have a spun coupler so the work had to be done anyway.

 

[Nige]

But I could not find anything, anywhere on how to actually test it. It was all remove the engine or all of the hydraulics and hope the coupler was bad.

All you had to do was ask.......
The test for a failed pump coupler is simple. Start the engine and look at the hyraulically-driven fan underneath the radiator/cooler pack. If the fan turns the pump coupler is good. If it doesn't - it's failed.

 

[jashford1]

OK, today’s troubleshooting.

I disconnected the inlet fuel line to the inline fuel filter and used my compressor to blow out the fuel line to the fuel tank, at this time I did not drain anything from the fuel tank. I started the unit, it ran very rough for approximately two seconds before dying.

I removed the fuel/water separator to dismantle and check all orifices and fittings for clogs and debris. Dismantled completely, blew everything out, did not find any debris or clogs. After reassembly and installation I started the unit, it ran very rough for approximately two seconds before dying.

I tested the transfer fuel pump by disconnecting the inlet hose to the fuel/water filter, I had excellent, strong flow. I reconnected the inlet hose, disconnected the outlet hose, again I had good flow through the fuel / water filter. Following the hose, it teed back into the fuel tank and continued to the fuel injection pump, I removed the hose to the fuel injection pump, engaged the transfer pump and had good flow to the injection pump. I started the unit, it ran very rough for approximately two seconds before dying.

During the two seconds it runs, it is running so rough it surprises me it starts and runs at all.

Almost forgot, to check if I’m getting sufficient air flow I removed the primary and secondary air filters just long enough to see if that made a difference, none whatsoever.

I’m at a loss where to go from here. Any thoughts?

 

[jashford1]

All you had to do was ask.......
The test for a failed pump coupler is simple. Start the engine and look at the hyraulically-driven fan underneath the radiator/cooler pack. If the fan turns the pump coupler is good. If it doesn't - it's failed.

Nige, not doubting you, you obviously know a bunch more than I do on this stuff. It seems if that is the only test, you’re indicating the fan itself will never fail?

 

[jashford1]

I went back out and with @ little help I bled the injectors. A couple of them seemed to have a lot of air, a couple not too much. That did not make a difference either.

 

[Nige]

Nige, not doubting you, you obviously know a bunch more than I do on this stuff. It seems if that is the only test, you’re indicating the fan itself will never fail?

This has to be approached logically. A 100% functional machine operating normally and the fan motor, or something associated with it, fails. The first symptoms would be overheating of the engine cooling or hydraulic systems, or both. Find and fix the problem and carry on.

For the coupler and the fan motor both to fail simultaneously out of the blue on a machine that was up to that point operating completely normally, unlikely in my book but always possible. Consider it something like this.....

 

[jashford1]

OK, today’s troubleshooting. I figured I would go back to the beginning on the not running thing. I started by removing and dumping both fuel filters, blowing everything out good. I reinstalled both fuel filters after having everything nice and clean.

Switched the key on, the small inline filter filled about 3/4 full. I cycled the key and the inline fuel filter remained about 3/4 full and the larger water/fuel filter filled maybe 1/4 then all I got was foamy diesel. I cycled the key and transfer pump two more times and all I got to the water/fuel filter was foam.

I removed the water/fuel filter output hose, turned the transfer pump on had what looked like good pressure and flow but all foam.

Out of curiosity I used my finger to plug off the out from the water/fuel filter. Turned the key on to start the transfer pump, it immediately filled the water/fuel filter with air free diesel. The small inline filter is still only about 3/4 full.

Replaced the water/fuel filter outlet hose. Cycle the key and the filter immediately filled with foam.

Looking at the fuel line setup, it goes from the Water/fuel separator filter through a tee that is attached to the fuel tank (?) continuing on to what I believe is the injector pump.

In an effort to eliminate things, I disconnected the fuel lines from the tee and jumpered them together using an inline fuel filter I had. After bypassing the tee the water/fuel separator filter stays full. Reconnecting everything back per original, foamy diesel in the water/fuel filter. Back to my test configuration, good clean air free diesel. But, the small inline filter is still only approximately 3/4 full.

I tried starting the unit, it cranked right up, ran rough and died in approximately 2 seconds. I started it 3 times with the same results. I have no codes or events, other than speed limited due to cold.

I am going to play with it tomorrow, if I cannot get it figured out, I’ll suck it up and call out a CAT technician.

If anyone has any last thoughts and things to try, I am open to almost anything at this point.