I have a D6D, and it is dead in the water-diagnosed as injection pump problem by the tech-fuel dribble out when when line disconnected from bonnet and cranked. Finding a replacement is a problem for them-and little info available because the engine serial and machine serial arent accepted by any online site-not even Caterpillar. I assume its because of the age of the machine so I came here. Dozer Serial is 4X4146, Arrange Number 8P1544. the engine is a 3306 (cant tell if its a 3306B-same problem with no clear way to tell as the serial doesnt show up anywhere)-engine serial number is 3N80264, Arrange Number 7N1539. Advice on the injection pump for diagnostics-replace-rebuild would be helpful. I would like any help anyone can offer-the machine is a workhorse here on my ranch-and I need to get it going again. I have a full service manual and parts book I got on ebay, and I dont think replacing the entire governor and injection pump assembly would be needed-maybe. The assembly looks like it is part number 4N1836-but cant be sure as there are multiple figures depending on Engine serial apparently. Picture attached for help. Will be trying to remove filter today to see if there is a part number behind it. Thanks for any help in advance-I need it!
Your machine is in Cat SIS and is not that old. Made in '79 (see below). Just have to know there are a few zeros not stamped in your data plate... Before you start condemning the fuel injector pump, lots of other things to try. Like verify you have fuel flowing freely to mechanical lift pump (if you have one) and then to your injector pump. I don't know your system that well but I would eliminate all the simple things (blocked fuel line from tank, clogged filter, air leak, etc.) before trying to replace any parts. The experts will be here soon... Oh, and if the tech didn't eliminate the simple stuff first and went straight to "bad pump", well, I'd second guess calling that tech back.
Hahaha, I guess not knowing the zeros were missing shows how much I know! Thanks for your comment my friend-no doubt I will get straightened out here by all of you guys-it is much appreciated.
Wow, By the look of that fuel filter, it’s hasn’t been changed in awhile, that engine needs a wash. The Cat D6d is one of best Cat ever made, hate to see them in this state
I am going to go pull that filter now and try to find some part numbers on the housing so I know at least which one of the injector pumps this one is, got access to the SIS with the earlier help and am trying to get this figured out. Tracking the free flow from tank to filter seems within my skillset!
Echoing that comment. What has been done in the way of maintenance on the fuel system recently.? Not a lot by the look of the photos. I would suggest to go though that system all the way from the tank to the injector pump inlet connection before even thinking about calling the pump bad. Sorry that's BS, as @LCA078 proved above. I can access the arrangement information and even the dyno test results from when the engine was first built. The engine is a 3306 by the way, not a B model.
Fair comments-and appreciated-you have all helped a ton already. Firstly-the opinion of the "tech" that was sent means less than nothing to me. I assumed (that stupid word) that when he told me he troubleshot the problem that he would have gone from tank to pump. Ordering a filter to replace the one I just pulled-and now have the part number off the pump assembly-but after what has been said and what I see that came from the filter...my bet is that the pump itself is fine (see pics of what came from the filter-which the fuel was freely dripping from after removal). I have never ever worked on a CAT engine or dozer-or anything like it. Paid a company for full filter and fluid service last year-clearly got hung out on that by not checking that old-add filter. But I can troubleshoot after 40 years in aviation electronics and computers...so I will have at this till my skills and luck run out-and thanks to you all for the help thus far-more soon.
IIRC you stated earlier that you have the service manual. I hope it is the correct one for your particular Serial Number. Cat Publication reference SENR7432. One section of that should be the Operation & Maintenance Manual. That document should be your first port of call for maintenance proceudres. I suggest that you start by draining the water & sediment from the fuel tank. Post photos of what you find. According to the O&M it is supposed to be done daily or every 10 operating hours. I'm guessing not........ This is what the correct Service Manual should look like..... https://www.ebay.com/p/1332531291?iid=321054923508
Yes sir, that is the manual that I have. I am embarrassed to admit that I have done nothing right in maintaining this machine-as you can tell. Ordered the filter-and will tackle the primary filter Monday and draining the water and sediment from the fuel tank and will post what I find. Thanks so much for the help and work on your side. Chris
Good- now’s a great time to give her a good scrubbing and verify all filters are good, fluids are topped off, zirks are greased, and radiator is cleaned out after the last maintenance.
After you have attacked the tank the next suggestion would be to disassemble, or as a minimum blow through with compressed air, the fuel lines. See below. Note the unions #6 where the lines come apart into sections. Nest question. do you have a water separator, like the one in the illustration, mounted to the engine not far away from the fuel filter.? Last but not least. Before you install a new spin-on fuel filter element, disconnect the lines and remove the head of the filter assembly (circled), then blow through it to ensure that all the internal passages are clear. Reinstalled the head and the replacement filter element.
Well your D6D is a Yank built Tractor from 1977 to 86 fitted with the Sleeve type injection pump, you will most probably have heater plugs set as a PC engine, your system looks to not have a constant bleed feature, these pumps suffer with any bad fuel /water involvement so your Master Tech might have been on the money saying the pump is failed, I am swapping out these pumps as a common thing as water is the death of them, in the U.K. a good standard of rebuilt pump is around £2'200 - £ 2'500 spot, lets be real here a Donkey could see that fuel filter was last fitted before the 5 gallon rebuild 10 years ago, so claiming you were Hung Out by your Service Company would be some tribute to put out, the filter is possibly a 1R 0750 and there will be a water trap filter pre to the main filter, I suggest you look at the engine oil filter to see if it has over spray on it also from 10 years ago, best of luck chap start reading your Service Book.
Yes, guilty on all counts. I run a cattle ranch with too many trucks, trailers and other equipment to keep up with it myself-and so yes, I have trusted people that probably shouldnt have-and am paying the price with this one right now. I have the OMI and wil be more diligent on this machine as it has been a workhorse until now and I abused it by not paying attention. I have new secondary filters-and headed out to get cracking now on the separator and tank drain and line blowout. I appreciate everyones help here-and the schematics sent over. I have access now to the CAT website and am getting familiar with the great info there to go with the OMI. My thanks to all for their expertise and comments.
If this is the level of service you've had on this tractor I reckon you do some due diligence on the rest of your equipment. Just my 2 cents worth.
Pulled the fuel line from the tank, jar full of diesel with no water, little sediment (see pic). Moved to engine to answer Nige's question re: the water separator, yes it has the one you sent drawing of. Pulled lower left plug from the housing-less than an ounce of water-pulled full element-FULL of water-put it in jar per Nige's request-98% water, 2% filthy chocolate milk diesel with sediment (see jar pics). I believe that the lower right separator housing valve is broken, as the handle freely spins without opening that valve-which I understand to be the daily water drain (?). There is the remnant of an old hose on that valve but it was long ago since it has yellow paint on it. I found the full separator part number-and believe the right move to get not just the filter element but the entire assembly so I can fit a new valve to the housing for daily drain, the CAT part picture attached here. However, my separator appears to be plumbed differently from the diagram Nige sent-the line from the tank goes into the lower side versus mine fitted to the high left inlet-so possibly better to get just the element and try to fit a working drain valve to replace broken one? Tomorrow will get the rest of the lines pulled and cleared as well as the filter housing pulled and cleared per Nige as well. Within few days should have verified clear fuel flow from tank to injection pump with new filters and separator element.
4 pic limit-here is the part listing-CAT doesn't list just the element that I can find. And the housing after I removed element.
The filter element is 8N9803.
That’s a Stanadyne fuel filter assembly. Cat didn’t build it. Out of production years ago. Fortunately, there are plenty of NOS, on dusty shelves, to be found on EBay. Many OEMs used them, including John Deere and GM. Terrible filter assembly. Prone to leak fuel and suck air. I recommend converting it to a Racor or something.
Still readily available in the Cat parts system
That’s good.
Attached a parts breakdown of the 9N-6519 showing the element and the drain valve should you wish to buy them as separate parts. I think maybe what could have happened is that, because it was impossible to drain the water from the separator, it got full over time and the water then overflowed from it to the spin-on fuel filter. Fingers crossed if you get those two items sorted out (don't forget to check the passages are clear in the head of the spin-on assembly) you might just find that you've dodged a bullet.
If you decide to buy piece parts for the water separator, make sure you get a few of the 1J-9671 O-Rings, because the ones that are in there now are probably as hard as rock.
I just ordered element, and a couple new valves so it can be drained properly. @Cmark thanks sir.
@Nige I have ordered a couple valves to properly set it up for maintenance-what you say makes sense as to what happened and why-hoping also for the luck on sorting it all and maybe getting away with not paying attention to maintaining like I should have. Great idea on the o-rings, adding to the order now- Thanks!
Just my thoughts. I would also order the gasket that goes under the square plate on the front of the pump. If it still doesn't go with the new filter, it's not hard to pull off that plate & see if the sleeves on the pump element racks are rusty/stuck. It will give you a good idea if any water damage has occurred inside the pump without guessing. If everything moves freely, it should still work.
Thanksgiving and my wife breaking arm and needing surgery slowed me down-but here is where I am now--------------- Started with tank, new cap with element>then cleared and cleaned filthy lines to water separator>removed separator from block and installed new element with new drain valve>cleaned line from separator to secondary canister filter (new)...filled all lines and filter to prime-still no pressure at injector pump output bonnet. see attached pics
Second half update- I did get the gasket for the pump housing cover @DieselFit (thanks)-and since no start after getting tank to canister filter cleaned and replaced-I removed the canister, its housing and siphon assembly>then the cover plate. Drained the housing first-clean diesel fuel with spoonful of water from the plug-but then found a few ounces of water on floor of housing and some sedimented crud-all seen in pics. Pump assemblies, lifters and cams all look operational and ok given how much garbage was in my fuel system from tank to filters-but clearly I have had water in the housing and therefore the pumps themselves. Next is to clean the housing out with carb/choke cleaner-then spray everything with clean diesel and reassemble all-get a new priming pump as the old one looks pretty contaminated in the valves. I have read a hundred pages of the manual and believe that the pump assemblies themselves have maybe gotten plugged with something and arent able to pump maybe? What am I missing that I need to do? Pump assembly removal for all six pumps is pretty involved-but if I cant get it started after this set of steps I think that has to be next?
It should still pump looking at that. Make sure that the rack shaft (the one with the allen screws that is going across the bottom of the pumps) can move freely. The sleeves should be able to flick up & down & move when the throttle is moved. The plastic relief valve on the bottom right needs to be free & the spring has to be re-installed when the cover is fitted.
Merry Christmas all- So I have a couple more questions-and a video and picture to help. In the video- video of pump operating -worked the governor control (throttle in cab) 2 full cycles and then cranked it over for 2 cycles. It appears to work as I expect from studying the manual-but the sleeves (operated by lever A in cutaway pic) are not moving when the throttle is moved-is that normal? The sleeves would cover the lower hole in the individual pump assemblies allowing them to pressure up properly as I understand their operation. Otherwise-all components appear to be operating correctly. I have highlighted with a white star in the video a valve that looks dirty-should I replace or clean it?-its a check valve per schematics. I think I have a decision to make here-clean the interior very carefully ensuring it is spotless>replace cover, spring, canister filter, new priming pump, gasket>prime and bleed system>check to see if it fires up. OR Remove the entire individual pump assemblies one by one and clean them up internally (assemblies are "B" in the cutaway pic)-assuming they may have gotten plugged with filth and water and this is why they weren't pressurizing? I could also replace all of the B assemblies at about 100.00 each, {picture attached}-this would remove them as a source of problems, but only if replacing them is easy enough, and I already found the tool needed and bought it for 25.00 if that is the way to go. So what do you all think is best-my underinformed opinion says replace all the pump assemblies, clean it all up rigorously and fire it up-but I am sure I am missing something still. thanks all-and Happy New Years to you as well.
That rack shaft connected to all the sleeves should move between shutoff & full throttle. You probably won't see movement between low idle & high idle because it will already be at full throttle without the engine running. Put an allen key into one of the sleeve levers & flick it to see if all the sleeves & shaft moves. (They should be able to move & flick back to position on their own). The governor is fuel lubricated as well, so there could be moisture/corrosion in the governor. The plastic relief valve can be removed and cleaned & maybe give the spring a little bit of a stretch before refitting cover, or replace both items if you can get parts easily. They are cheap. Those individual pumps will work if you can get the sleeve rack shaft moving freely & you can get 20-30 psi fuel pressure in the pump.
So I went and took a video of the rack movement-does it look correct-seems like its good and easy to move-not binding-but I dont know what range of movement is normal? Fuel injection rack movement
That looks good. Does it have a shutoff solenoid or is it manual shutoff? If it's a solenoid, maybe it is holding it in shutoff position. I would put the cover back on, pump up the fuel pressure with the primer & give it a go.
Yeah-at this point I believe what happened was that I had such a contaminated fuel system from tank to this pump housing that there was no fuel flow to keep the housing full of fuel-with both the water separator and secondary canister filter being full of water and sediment. I can't see how I would be better off-and maybe worse off-if I replaced all 6 plunger and barrel assemblies as there is no real proabability that all of them went bad at the same time. Gonna clean it all up-put it together and prime and bleed and see if I can get it to start. Interested in @thepumpguysc thoughts too-maybe after the holidays!
I wanted to thank everyone that helped with this-I decided to sell my ranch and move in 2024-and just got finished finally wrapping this all up. With the help from this group I was able to get it done so THANKS. Once I got the entire system cleaned from tank to pump housing, with new filters and water separator-blown lines, and cleaned out the housing good with carb cleaner, new priming pump and bleed valve, cracked the lines from the pumps to prime everything and cranked on it for a bit-fired right up and ran good as before..and spending a few hundred $ instead of thousands was a relief-just got it all fixed 2 weeks ago and sold it on the spot to a friend that helped me with it. Best of luck to you all! Chris
Congrats, Chris, on both getting the machine fixed up and selling the ranch. Best of luck on you next adventure.