We have a Deere 450clc that is having a fuel issue. It started out just losing prime over a few days of sitting then turned into a fuel starvation issue when under power. It is now at the point where it won't start. Fuel pressure at the test port was 80 psi when it was running. When it gets to 70 psi it sputters and turns off. When at idle right before it died I could pump the hand primer and it would stabilize. Fuel pressure would go back to 80-90 psi. I noticed air bubbles in the fuel return line out of the head. We thought it may be a suction side issue as some of the lines looked a little dry rotted. We replaced the return to tank line and the main suction line as well as all the one way check valves. Problem persisted. replaced the suction pump on the back of the engine. Bypassed all the filter housings with a line from the pump to the tank. We still couldn't start the engine. Air bubbles were still in the return line when trying to start. If we use the hand primer pump there are no bubbles in the return line. We pulled the injectors and found 2 that had hardened broken lower fuel sealing o rings. replaced all fuel o rings on all injectors. went to start it and still nothing. Fuel pressure at test port maxed out at 60 psi. Pulled the fuel feed line into the head and cranked. Solid stream of fuel going into the head. But, coming out of the head inlet is fuel with air bubbles. These bubbles will come out of the outlet line of the head when the feed line is hooked up. I was told by deere the way the main filter head sends fuel if it picks up air it will cycle the air back through the system instead of returning to tank. I am at a loss we have no codes so I am reluctant to put injectors in it as they are $1050 each only available from deere. And we cannot identify which injector/s is bad. What are the odds of this being a fuel injector without a code? Any other suggestions? We have bypassed or replaced everything I can think of besides the injectors.
12.5 liter Deere engine?
Yes. 12.5 I know try are a pain to bleed.
Injector stuck open and putting combustion in the fuel?
That is what I'm leaning towards. But we are not able to confirm through any codes. I'm not sure how to proceed to confirm the injector.
I made up a bleeder for those damn things when I worked for Deere out of an electric fuel pump and a couple of quick couplers.It worked well,
This machine has the dual fuel filter set up with the aux electric priming pump. It used to work pretty well before these problems. The electric pump would put 60 psi to the head and get rid of the majority of the air.
Does anyone have the method for accessing the service menu...and the list of error codes? I would appreciate your prompt help.
Engine service codes are available on the diagnostic display unit in the area of the battery box. See link below to the related pages of the Deere 450CLC web operators manual. https://techinfo-omview.apps-prod-v...recloud.com/omview/omt187112/09001faa801e430f .
Hydraulic systems live data and service codes are accessible through the monitor. To get into a Deere C series or Hitachi ZX -1 excavator hydraulic service mode. Press and hold the set button then key on or start. After bulb check release the button. Use the select button to scroll. .
Grateful... immensely... I wanted to access the error codes in the monitor's service menu... and its list of error codes
Check your messages.
I'm extremely grateful, Diesel Dave...it's exactly what I needed...you'll know how much it should be. Measure the pump control selenoide valve I'm attaching the photo.
I do not have the resistance spec for that pump control solenoid.
I am extremely grateful again, my dear diesel Dave.
That's a well-documented chase and you've systematically eliminated the right things. Let me give you the analysis this deserves. The single most diagnostic finding in everything you've described is this: solid fuel stream into the injection pump head, aerated fuel coming out of the head outlet. You've already confirmed supply side is clean. That means air is being introduced inside the pump head assembly itself. This is not a suction line problem, not a filter housing problem, and likely not the injectors. On the 6068 with a Stanadyne rotary injection pump (which the 450CLC runs), the distributor head contains internal nylon/Teflon seal rings on the rotor that separate the high-pressure delivery galleries from the low-pressure transfer pump circuit. When those rings wear — and at the hours this machine has — the high-pressure side bleeds back into the transfer circuit, creating exactly the turbulent aerated fuel you're seeing in the return. The transfer pump then recirculates that aerated fuel rather than drawing clean fuel from tank. Hand priming works temporarily because you're overwhelming the internal bypass with volume from outside the pump. The pressure drop from 80 PSI to 60 PSI after all your work is also consistent with this — you didn't make it worse, the pump was already degrading and it's now further along. On the 6068 fuel system, air bubbles on either the suction or return side indicate a problem that should be investigated at the pump or injector level. Regarding the injectors — your odds of this being an injector internal leak are low given one key fact: you're seeing bubbles during cranking, before combustion occurs. Combustion gas blowback through a worn injector needle seat only happens under firing pressure. Pre-fire aeration during crank points upstream of the injectors. Do not buy six $1,050 injectors on a guess. Even if one injector body is cracked internally, it would not produce the volume of aeration you're describing from multiple test points. The filter head air-cycling behavior Deere described is real — some Deere filter heads have an integrated air separator with a check valve that recycles aerated fuel back through the system rather than purging it to tank. But you bypassed the filter housing entirely and still had bubbles, so that's eliminated as the source. It may, however, be amplifying the problem after the pump generates the air. Here's where you are and what to do next: 1. Pull the injection pump and send it to a diesel injection specialty shop for bench testing. They can pressure-test the transfer pump, measure internal bypass, inspect the head and rotor assembly, and check delivery valve seats — all without guessing. A Stanadyne head and rotor kit is a fraction of the cost of new injectors and is a known wear item at this mileage. 2. If the injection shop benches the pump clean, ask them to do a leak-back test on the injectors on the bench. This can isolate a single failing injector body without you buying all six blindly. A shop with a Hartridge or Bosch test stand can flow each injector individually. 3. Do not let anyone replace injectors without bench-testing the pump first. If the pump is generating aeration and you install new injectors, the aerated fuel will shorten the life of the new injectors. One additional check before pulling the pump: inspect the injection pump's internal return/drain fitting — there is a small banjo or threaded return on the pump body that drains case fuel back to tank. If that fitting's internal check or seal is degraded, it can allow air ingestion directly into the pump body. That's a ten-minute look and a cheap fix if it's the culprit. A faulty injector leaking internally can cause fuel dump-off, but this should generate a fault code on monitored common rail systems. The absence of any codes on your machine further supports a mechanical pump issue rather than an electronically monitored injector or rail sensor fault. This machine needs a diesel injection shop, not more parts swaps in the field. You're at the boundary of what field diagnosis can tell you without a test bench.
10-20 ohms
I've pulled my hair out over 12.5L engines ( especially in 450CLC's ) with this problem before. The problem I've found every time is compression leaking into the fuel galley in the cylinder. head between the bottom of the injector and the sleeve in the head. With the injectors removed the surface of the injector and the sleeve should be shiny if the injector is sealed to the sleeve. If those surfaces are black from soot from combustion that's your air in the fuel problem. The sleeve in the head is supposed to be replaced every time the injector is removed and it's quite an involved process. If there's only one or two with signs of compression leaks you can replace those and all six sleeves and reinstall the injectors that were not leaking compression. It takes a special tool kit ( I think it's JDG933 ) to remove the sleeves and install new ones. The bottom tip of the sleeve also has to be ''swedged'' to enlarge the tip of the sleeve to fit tightly into the hole in the head and the tip of the injector won't fit through the bottom tip of the sleeve until it is wedged to the correct size. The wedging rod is included in the tool kit along with hold down jigs and several other items that are required to do this job. There's a lot of room for error involved in this repair ( such as driving the wedge rod through a piston that's up to high in the cylinder when the sleeve is being wedged ). The sleeves have to be tapped with a 7/8'' fine thread tap and removed with a slide hammer unless you remove the head. You also put a small plastic cap/plug in the bottom tip of the sleeve to keep metal removed by the tap from going into the cylinder. You also have to replace ALL rocker arm hold down screws and any other hardware as it is all torque-turn tightened and prone to break if reused. Where is this machine located? I'm pretty much retired but I wouldn't mind doing this job. If you need some injectors look on Ebay at '' Edsemarket ''. He's a friend of mine and I'm pretty sure he has several 12.5 parts from when he owned a couple 450CLC's in a quarry he owned then. As far as getting it running after filter changes, etc. either unhook the fuel return line from the head to the filter base and plug the line and cap the fitting or pinch the line closed with hose pinching pliers and crank the engine until it runs. That forces the air to go through the injectors instead of making the loop back to the supply side of the filter base It's safe to let the engine run for a short period ( 10-20 seconds ) with the return blocked because there is a 125psi safety relief in the transfer pump on the back of the head. It would probably be best to have a dealer or someone familiar with this engine to make this repair because of the special tools required and lots of room for expensive mistakes. Good luck, update this post if you need to.
@jrangel78 , check your messages
ohdeereme That sounds like a cat 3116 problem with the copper sleeves
I've worked on some Cat stuff but not a 3116. The sleeves in the JD6125 are stainless. Copper might be a better choice.
Actually when cat went steel you didnt see the problem near as much. The cups were the problem on the 3116 other than that the engine didnt give problems other than being a pain to run the rack on
I have fought with this and ended up building an adapter hose to go into the return line from the head with a needle valve in it, so i could start the engine with the return fuel blocked and then eventually open it up and let the engine run for a while. This system can be a pig. If the head gets a big gulp of air, even with the return line blocked it takes a lot of cranking to get it going. And then if you shut it off too early to re hook your return line up they sometimes wont start a second time.
I helped a friend put a head gasket on a C17 ( I think that was the model ). We had Cat TM instructions but it took me a while to figure out the sequence to adjust the valves and then adjust the Jake brake rockers. It was a weekend project so the beers probably added some confusion! Years ago I went through a few of the 4 cylinders that were in the original 953's. They were really good loaders but needed a little more in the engine department. I miss the equipment business but I had to get away from the new generation '' technicians '' that get but hurt if you look at them wrong. I prefer being called a '' mechanic ''. Technician is a title for jobs sissies and women can do!