New to me D3G BYR00977 has some issues after operating for about 1 hour. It looses power and starts cutting out and smoking a light colored smoke. When I idle it up past half throttle it starts cutting out, when i throttle back down it runs good and smoking stops but the power is still lacking, after it sits a little while it wilo go back to operating properly. All filters state they were changed about 300 hrs ago but was almost 2 years ago. I have a video but it will not let me upload. A friend told me to change all the fuel filters so I guess I'll start there tomorrow. Any other ideas?
Sounds like a fuel issue. I'm not sure on a D3G but there may be a screen in the fuel line that can plug up. On a D3B/931B it is inside a longer hexagon fitting going into the lift pump. Hopefully one of the Cat guys can show a pic. of the fuel system and lines.
blocked fuel tank breather wound be my first guess.
He could try taking the fuel cap off but if that was the issue I think you'd notice a problem pretty quickly. When I replaced a fuel cap on my skid steer with what was supposed to be a vented cap, the machine would start and die almost immediately and not start again. There was a vacuum when I removed it. Returned it and got a good Stant vented cap and no issues.
You can’t upload videos direct. You have to upload them to a video-hosting site such as YouTube and then link them. Before spending any money, why not try draining the water and dirt from the fuel tank (and from the water separator next to the engine if it has one) at the same time you are checking that the breather in the tank cap is clear.? The drain valve is under the rear LH corner of the tank. If it hasn’t been opened in a while you may have to poke a piece of wire through it to get whatever is in the bottom of the tank to flow. When diagnosing problems like yours, it’s always a good idea to start from the same place the fuel starts, in other words the tank.
IMHO if you are going to maintain it yourself what you also need is an Operation & Maintenance Manual. To download an O&M Manual click this LINK . You can enter the Cat Publications web site as a Guest. Put SEBU7081 in the box and click Search, you should see the illustration below.
Does your fuel filter & priming pump setup look like this.?
Yes that is it.
Thanks Nige, there was an old ragged copy on a leash behind the seat, I went ahead and purchased a downloadable version so Ill have on my PC.
You nailed it! I opened the valve at the bottom of the fuel tank and it would barely drip at first. I let it drip for 10 minutes and only collected a couple inches in a water bottle. There was a little water and sediment but not a whole lot. I took my air tank and blew in the valve back into the tank and it opened up good. I also pulled the filter next to the battery and drained out of the valve on the bottom. Again, not a lot but evidently enough to cause problem's after an hour or so running. I ran the dozer for 2.5 hours and it never missed a beat. Thanks again for your guidance sir!
Note in the maintenance recommendations the recommended frequency to drain water & sediment from both the fuel tank and from the water separator. Drain the tank first thing in the morning after having left the machine parked on level ground overnight. You'll soon get an idea of how often is necessary to drain it. In regards to the water separator I would suggest that you make that part of your daily walk-around to check fluid levels, etc. I would say that the fuel filter will probably need changing sooner rather than later but at least you are good to go for now. That filter head & priming pump setup is known to accumulate dirt in the passages. So the fact that you got dirt out of the tank and out of the water separator puts a question mark over it, even though the machine is apparently running OK at this time. So when you come to change the fuel filter, close the fuel supply valve, remove the filter element, the hose #1, the hard line from the back side (not shown), the electric pump from on top (it unscrews on a ring the same way as the filter), and finally remove the filter head from the machine. Ensure that you have photos showing where everything fits then remove all the plugs, fittings, etc, etc from the head. Blow through every orifice with compressed air or root through them with a length of wire to make sure there is no dirt anywhere. Then reassemble, reinstall on the machine, install the replacement filter, and prime the system. You should be good to go.
Well, it was working great for a while then the problem started again. I do think it's a fuel issue so we're going to drain the tank today and replace the twist on water seperator/filter
Problem started again. Do you know if there are any other fuel filters that may be plugged? I know the filter for the breather cap is bad, I'm going to call cat for a replacement today and go ahead snd replace the filter. We are also going to drain the tank and shop vac out what we can.
There is only 1 filter shown. See attachment. HOWEVER there is also a plastic mesh screen in the fuel injection pump inlet. See #13 in the illustration below. It is washable but if you find it damaged it can be replaced. Part Number is 237-5413. The O-Rings around it may also be dried up & cracked, and need to be replaced. If you change the fuel filter element go back to my post #11 above, remove the filter head from the machine, separate the electric transfer pump from it and clear out all the passages in the filter head and the pump. Make sure the pump is operating well (as in pumping bucketfuls) when you reassemble it all.
Do you have a schematic showing the fuel tank removal? We vaccumed what we could but there is still some rust or debris that we can't get to. I took off the bolts from under the tank but evidently there's more somewhere. I ordered a new fuel cap breather repair kit and the mesh screen fuel filter for the injection pump inlet as well as new washers and o-rings but they will not be here until next week. Interesting that there was no mesh screen when I disassembled the fuel inlet. This tells me someone had problems before and didn’t replace it. I'm wondering if the pump and injectors need to be cleaned out.
Here's the R&I and parts list for the tank. I'll bet there wasn't a strainer in the tank filler either.?
Actually the strainer was there. Is there a way to purchase the service manual? If there is I would be glad to buy one, if not woukd you please send the removal of the cab procedure? Thanks Nige
The complete Service Manual is Cat Publication reference RENR7310. New price $750 in paper, $535 on CD. Here is a link to one on eBay . There may be others. With 2nd hand paper versions the question to always ask is - "Is it complete?". The big binder should contain the Operation & Maintenance Manual and copies of large size fold-out electrical & hydraulic schematics. There is a single-page contents list shown in the 2nd photo of the listing. That contains every individual module that should be present. The O&M and the schematics often go missing. If that is the case then the offer should be priced accordingly because you would have to buy them separately. Attached the Cab R&I.
Well fortunately the tank wasn't as bad as I anticipated. We were able to flush it out pretty good. I disassembled the filter head like you described in post 11 and it had a bunch of rust flakes and muck in it. Cleaned it, blew compressed air thru the lines and reassembled. After 2 days of working it hard it hasn't missed a beat. Im surprised it ran at all with all the junk inside. Thanks again for all your help.