Cat D318 6 cylinder diesel

Hugh1950

Member
I recently bought an old Northwest 25 dragline crane with a Cat D318 6 cylinder diesel engine. The plan is to use this and my old JD dozer to put in a pond or two by putting dams in large gullies on our farm.
While showing me how to run it, the operator let it run out of fuel. The tank is about 2 feet below the engine, so there is no help from gravity feed to get it primed again.
He thinks the best way to get it primed is to put low-pressure air into the tank, and open what appears to be a bleed valve knob at the top front of the very large cast iron fuel filter on the front of the engine to bleed off any air, and fill it with fuel.
I did make up a gas cap with an air valve and pressure gauge. I unhooked the fuel line below the fuel pump, and got fuel flow out of the line with only about 5 PSI. I hooked it back up, but haven't tried the air bleed yet, Does this sound like the right way to refill the fuel filter? I didn't want to try this without advice, don't want to damage anything.
There is a fuel pressure gauge on the instrument panel, it shows no pressure when cranking. The engine fires a little on ether, but the short cranking cycles haven't got any fuel to the injectors.
Also, would greatly appreciate finding someone who is familiar with the clutch adjustment on the lower "reverse" shaft that operates the swing, travel, boom hoist, etc. I have operator's and parts manual, but haven't found a repair manual anywhere.
 
yes that is the easy way to bleed the system and 5 psi is plenty. Best to do a systematic bleed--trnasfer pump, fuel filter tower, injector pump bleeds, and injector lines at the injectors
 
can't help with your problems but I had a Cat 7T road grader with the D318 engine. Sold the engine to a guy who put it in a Cat dozer that used the same engine. So any old CAT mechanics in the area should be able to help.
 
Ok , first their was never a repair manual for the Northwest 25 models. Part manual only. The adjustments for the travel/swing , their are two adjustments , one on each side for the wedge clutches. I can explain better by phone. The fuel issue, the Northwest machines came with a hand primer pump but, most have been removed over the years. Forcing air in the tank will send fuel to the fuel tower out the bleeder on the Cat engines but, that is far as it will go. Once the fuel is that far you will need to loosen the fuel lines on each injector crank engine to remove air. Once started, crack each line again to remove rest of the air if not running properly. Beware , you just might have to replace fuel filters also since it was run out of fuel. I ask earlier for your location. I may know of another Northwest collector/operator in your area that will be willing to assist.
 
You sure it's out of fuel and not clogged filters from old fuel?
Anyway you can put air in the tank but that will disturb a lot of settled crud.
Cab engines all had a hand pump primer usually close to or on the injection pump.

Unscrew round cap, pull out and pump with bleeder valves open..
Tom
 
The hand primer was an add on,best way of bleeding is to remove the cover from the filter and fill the housing with clean fuel,open the bleeders on the pump,keep filling the housing till fuel comes through,top up the housing and put the cover on and try to start,its not easy to get the transfer pump to lift the fuel once it runs dry so a little air pressure will help.
AJ
 
Ya, I finally figured that there wasn't a repair/maintenance manual. The machine did come with an operator's manual, but it is pretty vague, leaves out a lot. I did get a parts manual from Jensales, the assembly drawings are helpful.

Machine had just been used to enlarge and deepen a commercial fishing pond when I bought it. We are located in West central Indiana.

I opened the bleed on the fuel filter tower, put in about 5 PSI of air, after some time I did get a steady stream from the bleed drain line. Cracked open the fittings above the injector pump, opened the compression release, cranked until I got steady fuel squirting out with no bubbles, then did the same at injector fittings. Tightened all the fittings,started cranking, quickly closed the compression release, and she started running instantly. Has a replacement D318, says it only has 750 hours on it.

The clutch is another issue. The one on the lower(reverse)shaft on the operator's side of the cab is slipping under load. This is the one that swings cab to the right, or travels you forwards, depending on which jaw clutch is engaged. The cab will barely swing right (until it hits the slightest resistance), but clutch does not have enough grab to move at all in forward, she only crawls in reverse. I can see the clutch slippage if I have someone else move the engagement lever while I'm in back of the shaft.
The previous operator and I loosened the bolt on the adjusting collar, and tightened the collar about 1/8th of a turn. didn't seem to help much if at all, so we did this 3 more times, no improvement. Clutch doesn't seem to "toggle in" as it should. Probably tightened it too much.

Is there any way to tell if the friction wedges are worn to the point where you have no adjustment left? By eye, they look OK, system is far from being "metal-to-metal" anywhere. Maybe the wedges are glazed from slippage?

Also, I can't get any function from the long lever on the left,the "rotating brake control" which is supposed to lock the upper deck (cab and boom) to the undercarriage when traveling. the cab and boom swing uncontrollably from side to side as the uneven terrain causes the bucket to swing back and forth. Manual says push down and forward on lever to engage brake, but I can't get much motion from it. I'll have to crawl around a bit to see how this is supposed to work, might need adjustment.

Thanks to you and all others for your help!
 
I'm in West Central Indiana,too close to the "flatlands" for comfort, the crane is a bit to the South, down in the "hills and hollers".
 
Thanks, your advice worked perfectly!

After reading some real "horror stories" on the internet of folks who couldn't restart after running out of fuel, I thought I was going to be in for a real hassle.

The previous operator was trying to bleed it by cranking only, but he didn't realize the engine has a compression release! Using it makes a huge difference. Also, he was cranking with the throttle closed, so the pump unit was hardly moving any fuel at all! Unfortunately, the engine is battery start, so he would get a couple cranking revolutions, and then the batteries were dead.

After bleeding, I cranked her for a second or two with compression released to get some speed on the pistons and inertia in the flywheel, quickly closed the compression lever, and she started instantly!

Thanks to you and the others who replied!
 
I stopped at my local courthouse, there was no one there at the time who knew anything.

I'm hoping that since the new administration has reversed the EPA's ridiculous "Waters of the U.S." (WOTUS) edict, maybe the government will be more reasonable towards pond building.

My area has a huge amount of small farm ponds, put there years ago when the government actually encouraged and helped farmers build them. Odd how much things have changed in a few decades.
 
Thanks for your offer of help! My cell phone is seven 65 three 66 seven270, call anytime.
The previous operator had been trying to bleed/prime the engine by cranking, this would have taken forever, batteries go flat pretty quick, he didn't realize there is a compression release! Also, he was cranking with the governor level in the "stop" position, so he wasn't moving any fuel at all!
The fuel filler neck was 2"MPT, so I put on a 1/8" reducer coupling with a Scrade valve, put in 5 PSI from my air tank,and in a short time had fuel coming out of the D318 fuel filter tower. Putting pressure slowly into the topside of the tank doesn't risk stirring up any crud in the bottom of the tank.
Now my major problem is that the operator side clutch on the lower (reversing) shaft is not transmitting any torque. She will not travel forward,swing to the right, or raise the boom. I lowered the boom to where it has slack in the cables, but the clutch will not even take she slack out when I put it in "raise" position.
The operators manual says that there is only one adjustment on those clutches, rotating an adjustment ring in or out to adjust the "throw" of the driving disk against the driven disk. I've moved this in and out, no change to the clutch operation. The friction wedges look to have plenty of thickness left, but they barely touch when the clutch lever is pulled back all the way. Maybe they are worn too short, or the linkage is "bottoming out" and running short on throw.
An experienced crane mechanic from the coal stripmines told me there is another adjustment that the manual doesn't mention, but did't say what it is. Maybe screwing out the rodeyes on the linkage rods to get more throw?
 

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