Hi guys. HEEELLLP> Cat D3B 23Y loses fuel after a short time. I have replaced the fuel transfer pump. Put a new pressure gauge on the capped ( rear) side on the T on top of the fuel filter ( new 3 hours ago) to check fuel pressure and got zero on old pump. I had checked the little inlet screen on the pump. Clean. Last month I installed a in line strainer used on new Holland diesel tractors. Very little debris is showing in the strainer. Topped off fuel, go the new transfer pump in in about 10 minutes. New muffler too. Anyway. I had put a t in the line between the tank and the transfer pump inlet with a long hose up to the cab and put a fuel line ball valve on it so when the bloody tank screen plugged I could blow into the line until I heard bubbles in the tank. Much to my surprise, I get a zero reading for fuel pressure with the new pump. The machine starts easy and runs sweet until it starts losing fuel. I can run a long time at very slow RPM but as soon as I increase fuel it will start dogging down to die if I don't idle back real fast. Sucks. Oh, I did find my tank cap was dirty and cleaned it good. No change, except the tank doesn't get a vacuum on it now. Anybody got a fuel circuit print so I can track down that orifice someone mentioned? What is the very best diesel fuel line to use if I need to replace all of them? Thanks, Jim any advice you can also e mail me at [email protected]
chief jim, jim, something in the return side of your fuel system actually creates the pressure. it is sometimes an orificed fitting, sometime a relief valve. on some cat systems it is 90 degree jic/boss fitting on the outlet side of the fuel pump, any jic hydraulic fitting can go in its place but it is suppose to have an orifice and sometimes gets replaced with standard hydraulic fitting. think of a garden hose with no spray nozzle on it the gauge on that hose would read zero, now install a spray nozzle and close it slowly, as you close it the hose pressure will come up. disconnect hose after new transfer pump, put hose in bucket, crank for twenty seconds, should be a gallon or more. if not suction line is plugged, bad new fuel pump, or whatever is driving that fuel pump? ..........theironoracle
Thanks. I will replace the entire fuel line from tank to Transfere pump. Purge air. Find return line to tank and start squeexing that return hose off while watching the pressure gage I have installed in place of the cap on the rearward pointing T on top of the fuel filter. If the supply line from tank to t pump has a pinhole, one guy said it would act as if plugged. The guys who worked on this dozer before me put a bunch of air pressure in the tank. sigh... They bulged it and the coatings are flaking off all the time inside. i will indeed cut a place for a flanged cleanout opening soon. So... if the flow from tank to t pump is healthy, the tank vent is clean, the inline strainer is clean, the filter and pump are new and I crank for twenty seconds, I should get a GALLON of fuel? WHen I reconnect the discharge to the injector pump, by all rights I should see the 40 PSI, right? If not, the restrictor is missing, yes? WHAT SIZE IS THE ORIFICE SUPPOSED TO BE? I can easily make one. Just got back from the CAT store. got prrints for the fuel system. The parts dude could not identify anything that was a restrictor, orifice, metered opening or whatever. SHEESH! Guess I'll bug the service guys Monday mornin.
Chief : when it runs out of fuel, if you were to open the bleed screw on top of the fuel filter and with the hand primer pump on the side .... pump it ... does air come out of the bleed screw or bubbling fuel before solid fuel comes out ??? ........ I had all of these sympthoms you write about on my excavator ..... I replaced parts as you did and nothing fixed it ... one thing to note tho was if the tank was full until about 1/2 full it ran flawless ....... drove me nuts ....... long story short it was a fuel line leak, but not leaking fuel out but sucking air in right by the water separator .... I eliminated the water separator and installed an inline fuel filter from NAPA ~$2.00 problem solved ..... what a PIA that was but now it saves me alot of bucks replacing the main fuel filter from plugging with rust debris ....... just a thought for you to check too ....cheers... keep us posted
D3B starved for fuel My kingdom for an attached primer pump. This machine doesn't have one. One reason it is such a booger to trouble shoot! I have NAPA 1/4 inch hose to replace the supply side hose. With my luck there will be a pinhole in the steel lines, although I see no indication of weeping. I am ertain the reason will be simple when found. Hey, do they make a filter housing with a primer pump or is it the transfer pumps that have a manual lever? I'll ask the CAT store about that on Monday. I keep the tank topped off at all times to help reduce condensation. The big mystery to me is this thing ran great under all conditions for a while. Maybe three hours. Oh well, that was in the winter. Guys, I repeat: New transfer pump. even at high RPM ZERO fuel pressure. Yes, I checked the gauge, it works. WHAT IS THE CORRECT SIZE ORIFICE to provide restriction and create the 40 PSI fuel pressure to the injector pump???? I can easily make one, just don't know the diameter. Is there a minimum flow rate for required flow through the inj pump? Thanks...
Chief, I'm no Cat D3B expert, but does your lift pump have a sort of oval shaped plate held in place by two hex head screws? If so, that's where a manual primer pump is fitted. If you're seeing zero pressure on gauge after fuel lift pump, sounds to me like something blocking your line. I had a Cat 320D give me fits, doing all the stuff you're doing, until I finally drained tank and removed elbow on bottom of tank where fuel supply line connects, found a small stick lodged in elbow. Not saying that's your problem, just saying sometimes the smallest thing can cause big problems.
D3B Starved for fuel HOT DOG! Made some headway. I got sick of idle rpm to try and smooth a fence line. And about the time I decided to shut down. IT quit. I had pinched off the return line to tank and got zero on pressure gauge. Again. Anyway, I started making flow checks down the line fron tank toward transfer pump. Finally got to only a section of line between in line strainer and t pump. NO flow. There was a fitting transition from hose to tube BEHIND the fuel filter. That fitting was full of crap. Must of been living in that hose sice before I installed the in line strainer. New hose, runs GOOD on 4/5 throttle. VAST IMPROVEMENT. I still have not found the restrictor for the return to tank. Any of you folks found out what size the orifice is? CAT was not help on the size, yet. Oh, there is no room for a priming pump to go on top of the transfer pump. Too bad. Only $16.50 on E Bay.
Good to hear you've made some progress getting it sorted out Chief Jim.
Jim, Here's what "the book" says about the fuel system. Fuel is pulled from fuel tank through primary fuel filter by fuel transfer pump. From the fuel transfer pump the fuel is pushed through secondary fuel filter and to the fuel manifold in fuel injection pump housing. A bypass valve in the fuel transfer pump keeps the fuel pressure in the system at 20 to 40 psi. A constant bleed valve in the outlet of the fuel injection pump lets a constant flow of fuel go through fuel return line back to fuel tank. The constant bleed valve returns approximately 9 gal per hour of fuel and air to the fuel tank. This helps keep the fuel cool and free of air. The bleed/bypass valve is mounted vertically in a housing in the bottom of the fuel injection pump. The valve is #14 in this illustration. Be careful taking out the plug #16 in case the spring #17 decides to fly off into oblivion.
nige, that is awesome info, great job finding and providing that info for someone you don't even know!! i hope i can contribute like this in the future........theironoracle
NIGE, thanks for the great info. Too bad the print you have is not the same as the option on my engine. MAJORITY OF CAT engines that use a restrictor orifice to create back pressure and use the same kind of 90 degree fitting. Exactly as described earlier. CAT STORE fuel system guy GAVE ME THE FITTING an hour ago. We measured the orifice hole. It is between .026 " and .027 " in diameter !! I'm off to the mountain and try this thingy out. Will advise!
That's the problem with sucking diagrams out of Parts Books. With all the possible options available sometimes what you have on your machine is not what the book shows.
ALL, Nige , Willie and company. Well, other than now being bloody well addicted to starting fluid for some other worldly reason... The beast HAS POWER, RUNS SMOOTH, runs COOLER while pushing loads more stuff! At least a 25% increase. Oh, it also idles slower and smooth as silk. Haven't put a gauge on it. Just going to move a few thousand cubic yards of old coal mine trailings to fill in a chasm so's we can get a fence across it. The guys in service at the Cat dealer pulled out the stops and actually scavenged the orifice fitting from a 3206. WORKS. Again, the orifice is .026 or .027 depending of who tweaks the mike. Thanks guys! Willie, is there a specs page that this info can be posted on? Jim
Always nice to hear of a happy ending ............
Willie, Follow up. After running for a while and parking with the nose down, level or up, I find the beast may or may not have fuel enough in the bloody injector pump to start. I went to the auto store and got a MR. GASKET Electric diesel fuel poump. ( green housing) The thing is supposed to discharge 9 to 14 psi. Anyway, i start the electric pump prior to cranking the engine and it works. I can hear the system purging back to the tank and that is a good sound. Point is that if there are air leaks or whatever, the electric pump seems able to compensate quite nicely. Thing works.
A fuel problem that occurs with D3C, is the outlet tap of the fuel tank blocks up with muck. The engine acts like it has a blocked filter but its only the tank outlet. The way to get going is blow back through the fuel line back into the tank. This may or may not happen with your machine.
Sometimes you gotta go back in time to find the answers you need... if any of you are still alive... thank you. If anyone is still on this thread... what is the the banjo bolt with the filter in it, located at the bottom of the manual hand pump called - Cat D3B 1981 Vehicle 23Y 0763 and Engine 45V27911... need to source that little filter...
Old thread WARNING: Since the D3 is Japanese, and the Japanese used those banjo bolts in everything diesel, I'd guess you could borrow one off any Japanese diesel from the 70's-90's in the junk yard, or get one from any diesel injection shop.
Thanks for getting back - The banjo bolt is still mint but there is a little inline filter that screws into it - having difficulty finding the filter - cat guys here in RSA dont even know what I am talking about - has anyone got a name for it other than " a filter that fits into a banjo bolt" that was too much for the cat dudes to understand...
I don't know what to tell you. Somebody will have the resources to find a part number for you. Or I promise you there's plenty of them in any junk yard with Japanese diesels. Or any diesel injection pump shop should have one or know how to order one easy. The cat guys will have to be able to look it up on a parts diagram before they'll believe you, parts counter guys aren't always the most experienced mechanic in the place (never?)
I think you will have to purchase the entire fitting. Far as I can tell, there isn’t a number for just the screen. I assume you already tried to clean the one you have?
And espcially if they work for Barlows. Don't ask me how I know that............
You mean #22 in the illustration below.? 2W-7671 Screen As. Sells for $11 in the US, no idea about RSA.
Just look at that!