Hello, new to the forum but not new to forums. I purchased a 977L with a 3306 in it about 6 months ago. The loader had been in a fire and i felt like I could revive it. The fire was mainly in the back, the guy had been pushing burnt brush piles and caught the fuel line on fire. The fire never got hot enough to warp any metal, but barely enough to take off the paint. I have slowly been replacing seals, hoses, springs, and those sort of things that heat can destroy. I spent countless hours and replaced hundreds of seals towards the back. The heat barely made it to the back of the motor, just enough to burn off the plastic oil pressure gauge 1/8" line, but that's about it. I had to redo the turbo and filters, changed the oil and fuel line etc. Once I finally got everything squared away I used it for a little while, and this thing is a beast. At that time the oil was fine, no problems there. Then one day I noted the oil pressure slowly dropping as the motor gets up to running temp. I wouldn't run it when it would drop to low, shut it down and wait until it cooled off and would run it a couple days later. Eventually, it got to the point that my oil started to come out the blow by tube. So I changed the oil, the 3306 motor hold 7 something gallons, and I noticed that it was real thin and smelled like fuel. Instead of 7 gallons, I had about 15 gallons of black diesel. So in the never ending search for this issues, I talked to a few people about it. Most people said to change the transfer pump. So I did. It was an aftermarket one btw. I shut off the fuel, changed the pump, ran it and checked the oil, the oil appeared to be ok, but I was still losing oil pressure upon warm up. So everyone told me the next thing was to have the injection pump rebuilt. So I sent it in, 2200$ later I got it back. The company stated that the inside was trashed, but the housing was good. They replaced a bunch of parts and seals. Stated that the plungers and barrels were bad, and that would cause the extreme amount of fluid in the crankcase. I slapped the IP back on and thought I had it fixed. Ran it for about 5 min and busted a hydraulic line so i shut it down to fix that. Ran it again an noticed that my oil pressure was dropping like it had before. I thought it had to be an oil pressure problem now that my leak was fixed so I started searching there. I started it up one day and a few second in I could hear fluid gushing out onto the ground. My first instinct was that I blew a radiator hose due to all the liquid. Got off the machine and noticed it was red, not green. Farm diesel. Took the valve cover off and ran the motor just long enough to get a video that I will post. This time, I had left the fuel valve on because I thought my fuel problems had been fixed. There was red diesel shooting up all over the place on in the valve cover. So I started trying to rule things out. I'm thinking a cracked head, blown head gasket, bad injector, bad injector cup, bad return line. Well, i took the IP off and ruled out all of those options. Before I did, I drained the entire crankcase and oil filter. Let it sit for a few hours to get it all out. It was down to a drop about ever 30 seconds. Removed the IP pump, and plugs the hole where the fuel would enter. I turned on the fuel and pressurized the system. With the drain plug still out, after pressurizing it with the primer pump, the drops went from 1 every 30 seconds to 1 about every 2-3 seconds. So that tells me that there is fuel getting into the crank from this first half of the system and not the the IP and beyond. There is the transfer pump, that has 3 holed in the timing gear hosing, when i prime it, fuel comes out of the top larger hole, and the smaller hole on the inside of the slot for the transfer pump. but nothing out of the larger bottom hole, which i guess may be the line going into the IP. The fuel filter housing also has a little maze gasket on top, don't know if that could be causing any problems, and then there's the timing gear housing that is controlling the IP, I guess it could be cracked or have a seal out that is allowing the fuel to go past the timing gear down into the crank. At this point, I have exhausted my resources and money, and I just need it fixed so I can use it. Help would be greatly appreciated. I know that the fuel can drain in it while its not running, and I'm guessing drain even more while it is running. Everyone said typically the transfer pump will do this, but I don't quite understand how. Is it possible that my aftermarket transfer pump is bad? I just can't seem to find the leak... Serial numbers. 977L- 11K05382 Arrangement number- 3P6259 3306- 3N4192 Arrangement number- 2P6804 valve cover video- https://youtu.be/-Kw7_W-TTjY Oil draining video- https://youtu.be/yomQlYWmvaQ Colten
It's not too late, please go to edit and make PARAGRAPHS.
back lane frei I apologize for that, but it is not letting me edit the post, says i do not have editing privileges.
That's alright, I was able to understand it once I got through it. Not as bad as it first sounded. Sorry, I can't help you, but somebody will be along before too long with good advice. Some of us are just a little slow in the reading department sometimes. Usually you have one hour to edit posts, "edit post" is to the left of reply, and reply with quote under this message.
Thank you very much! I will remember that next time I write such a novel!
Grease-ball logic would indicate that if fuel is reaching the crankcase while the engine is not running, then fuel must be gravity feeding to the transfer pump, where it is passing a defective seal. You will find life much easier with a complete parts and service manual. Regards, Clark
I would think you have a small O ring leaking on the filter housing, turn off the fuel tap and whip off the injector pump, blank off the fuel feed to the I/pump and turn on your fuel tap and look for leaks coming from the Aux Drive, by now I would expect the crank and Turbo to be needing some interesting repairs, so I can recommend cutting open the engine oil filter and checking the pleats for sparkle? tctractors
I have a service manual and a loader parts manual but no engine manual. With the injection pump off, it still leaks to the crank case. With the injection pump off, the circuit to the turbo is removed. I know the flow goes through the transfer pump, but it's a brand new after market pump, there are very few moving parts and seals. The fuel does not flow out of the area where the injection pump mates to the time gear housing. So I feel like it has to be running down the time gears themselves. But the question is why, and how to fix it And as far as the housing goes, there is no external leaks that leak out of the engine, only into it. The injection pump is freshly rebuilt by a reputable diesel injection pump shop.
I may have an engine parts manual for your machine. I'll look tonight when I get home. If I do and you need it, just pay shipping and I'll send it to you.
That would be awesome thanks!
I have an engine manual for 3306. If I interpreted it correctly, your fuel transfer pump should basically have a seals to keep the fuel and oil separate. Between these seals should be a cavity with a 'weep hole'. In theory if there is a seal failure you should be able to see it unless it is plugged off somehow. That being said, you would have to have 2 bad seals and the weep hole plugged for the fuel to be getting in the oil through the transfer pump. Since you have installed a new transfer pump I'm guessing that it is pretty unlikely that is your problem. If I am incorrect hopefully someone will come along and correct me.
I will take it apart and look for any seals i can find and post some photos tomorrow, I hear people all the time say that this is the culpret, but as it stands im not seeing it right now, but I will check
Usually seals are designed to seal one way, so one bad seal and a plugged up weep hole would cause it to leak. As long as the weep hole is open you should be good, right? Weep holes can get plugged by lots of stuff though, mud daubers, paint, etc.
Take tctractors advice
Fuel in the E/O will take the crank out very fast, it usually knocks out the Main bearings in the 333C 3306 engines, the bearing spin in the block and scrap the block, crank, turbo, and camshaft in quick time, the big ends are often found to be good, anyhow the injection pump fuel pressure pump and filter head should have drain lines from them that are clamped together dropping down to vent in the belly pan? tctractors
I found my 977/3306 engine parts book, unfortunately it is for a newer model than what you have, the serial and arrangement numbers don't work with yours.
That's ok I found that I can pull up everything I need on my local cat dealership website. Thanks!
Ok here's an update, finally got around to messing with it again, I got a 3rd transfer pump and no fix, I took my IP back to the injector people and they tested it all day long and said there is not a thing wrong with it. I have replaced the the fuel lines, injectors, and precombustion chambers. So with the IP pump off, I hooked up the fuel line to a small amount of compressed air, plugged off the fuel where it runs to the IP, and at around 20psi you can hear air escaping into the accessory drive. I took the filter housing off with just the lift pump still on, and plugged off the hole, and does not let air escape into accessory drive. I went through the filter housing and found nothing. After looking at it a while I remembered I plugged off two holes when I first got it because they were leaking. I found the one on the block in my manual, and its an oil supply. I also plugged off a second hole on the underside of the Accessory drive, but could not find what it was supposed to be. I took the plug out and the lift pump out and blew air through it, the air came out a whole in the housing between the oring and the housing on the lift pump, that hole goes through and sends something back to the tach that bolts onto the lift pump. So my question is does the lift pump use oil lubrication? and if so where is the oil coming from? channels in the accessory drive housing, or that plug I blocked off? The accesory drive is a 2p-7712
This is why you should check your fluids level every time before starting.If to full why,If to low why ,if wrong color why ,a little time here can save A LOT OF MONEY!!!
I'm getting way confused here. As I recall the fuel comes into the accessory drive housing back by the primary strainer and then goes to the suction side of the lift pump then out to the fuel filter housing and through a short pipe with a couple orings on it and into the front of the injection pump. There should be a steel line coming off the bottom of the accessory drive that is connected to a port in the hole the lift pump mounts to so that if there is any fuel leaking from the lift pump seals it will drain to the outside and not make it's way into the engine oil. It's been a few years since I worked on a 3306 but seems like there is a small oil passage that gets oil to the drive gear of the lift pump. Or it might be that they just depend on oil mist from the front bearing to lube those gears. The lift pump itself is only lubed by the fuel it is pumping. I believe the fuel gets to the lift pump trough passages in the accessory drive housing and there is a mounting gasket with hole to match up with those. Thenthe ouput from the pump goes through this same gasket opposite the inlet side and into the fuel filter housing and then to the fuel injection pump. There maybe a small 1/4 inch pipe coming off near the top of this filter housing that is used to bleed off the air when priming the fuel system with a valve you open to let the air out. Usally that line and the one from the bottom of the accessory housing are both connected to a bracket down near the oil pan surface of the block. I'm just not understanding where you are putting the air and where it is coming out in post #18 above and also you mention places you had leaks an plugged holes just too much disconnected information
Guess to start fresh I would say remove the lift pump, the fuel strainer, the spin on fuel filter and line coming from the fuel tank. With the lift pump off there should be two holes on either side of the big hole the pump gear goes through. If you blow air into the one to the left of the big hole you should get air out the place where the fuel strainer screws on the bottom of the housing. If you blow air into the small hole to the right of the you should be getting air coming out where the spin-on fuel filter mounts. Then maybe repeat that last test with the spin-on filter in place. Now the only place the air should go is maybe back to the tank through the injection pump. If you are now hearing air inside the accessory drive housing I am at a loss to understand that without being there myself.