Today I'm going to run over a Kenworth service with a Cummins engine in it. With the truck on the hoist up in the air brakes released I spray all the fittings, air tanks, hoses, all the connections. The air bags and check for leaks. I spray it with soapy water so any small air leak will come up with bubbles.
Use a filter wrench to loosen the filter so that it is hand tight. Don't loosen it too far that the seal at the top is broken otherwise the oil will start leaking down. Now that the filter is loose get a center punch or a screwdriver, something with a sharp point and pierce the bottom of the filter. Set your drain tray up underneath it, pull your spike out so that we are now draining the oil filter. While the oil filter is draining check
your gearbox level this gearbox has a sight glass.
Inspect the drive shaft as you work your way towards the back of the truck. You can see that the diff pinion seal is leaking on this one. These are the sorts of things you're looking for when servicing a vehicle. Check the diff oil level make sure you check front and rear diffs. Inspect your brake linings, inspect your bushes, s cams. check your brake boosters the mounting points, checking for cracks.
Having a look at your air lines making sure nothing's rubbing. Check your air tanks make sure that they're secure. Now that your oil filter has had a chance to drain a bit it won't be as heavy so you can unscrew the filter. This can be done relatively mess-free although oil may still drip from the filter housing. Wipe off and inspect the oil filter base making sure the sealing surface is okay.
Put some rubber grease or oil on the seal of the new filter. Fit the new filter taking care not to bump it on anything on the way up getting dirt in it. Spin the filter on until you can feel it contact the filter base then tighten it a further three quarters of a turn. I've always been against using a filter strap to tighten filters but on this engine I find it difficult to get the 3/4 of a turn required without it. So be careful not to over-tighten the filter or damage it. Remove the sump plug. A couple of common mistakes to avoid is make sure your drain tray, if you're using one like this is empty not half full so then it's not going to overflow. Another one is make sure that you line your drain tray up so that the oil goes in there. It's a bit easier on a sump like this where the oil drops straight down, but a lot of plugs are on the side so take care lining those up. Another one is if you have a little bit of crap in the drain tray and it blocks the hole a bit so that the oil hasn't got time to get away and your drain tray then overflows. Check your steering joints I use a big pair of multi grips and squeeze the joint, this gives me a fair indication of how much wear is in it. There should be very little when squeezing the joint in and out. Check your brake linings for how much it has worn and for signs of a leaking wheel seal. This truck is fitted with an auto grease system so check those grease points. By now all the oil would have drained out of the sump so fit your sump plug following my sump plug rule. This truck has an after treatment air filter that needs to be changed on every service. The air pressure in the filter can make it difficult to remove. The filter will be firm until the seal lets go and releases the pressure. Then it's the same as any other filter. Apply some rubber grease screw it on according to the diagram on the filter it's usually three-quarters of a turn after touching the base. The last thing I do before lowering the truck is loosening the fuel filter. I think we should make some of the blokes who design these trucks work on them because this fuel filter is a real pain in the ass to get to. I use a long extension bar and it's not too bad when you've got it up on the hoist.
Now that the truck is back on the ground the first thing I do is fill it with oil. This engine takes 47 liters we have an automated oil pump that you can set the litres that you require. A couple of mistakes that I've seen happen before is that the units is set to gallons instead of liters so you end up putting 47 gallons in instead of 47 liters. To lower the risk of this happening I like to do everything in a routine so I know once I get my oil pump pumping I can then go and do my two fuel filters. By time I've done that the oil pump should stop pumping. Another oh shit moment is if the oil pump which is set on automatic and is pumping away somehow gets bumped or falls out of position and oil starts pumping on the ground. To decrease this risk I get a piece of rag and tie the pump to the fill pipe.
Remove our pre loosened fuel filter this can be quite a messy job because the fuel filter does not fit out down past the chassis rail. It has to come out the top and has to be tilted on an angle to get it out so all the fuel that's in the filter I remove with a siphon hose. I pre-fill the filter a little bit on the ground before maneuvering it in. See how there's a plug in the middle so that you pour the fuel in and it has to be filtered through the filter before it goes into the engine. The rest of the pre-filling needs to be done when the filter is sitting in there on the chassis rail.
Remove the plug and spin your filter on same as every filter do it up till it contacts the base of the filter housing and then tighten it 3/4 of a turn. Once again I find on these engines you often have to get a filter strap and tweak it to get the 3/4 of a turn. Be sure to wipe off your filters- one so that it is a neat job and two so that you can see if they leak. Moving on to your fuel Pro filter, Undo the top cap so that the filter can vent. This allows it to be able to drain easy. Place a container underneath the filter. Open the tap and drain the fuel down so that it's below the collar level. Use the filter tool to undo the collar.
Remove the old o-ring, clean the filter bowl especially the sealing surfaces. Also remove the o-ring from the filter cap. Remove the filter cartridge allowing the fuel to drain out. Make sure you remove the bottom seal if it stays on when you remove the cartridge. Wipe your sealing surface and the thread. Put a small amount of rubber grease on the bottom seal and fit your cartridge. Rubber grease your o-ring and fit it to the fuel bowl. Fit the fuel bowl get your locking collar, now apply downward pressure to your fuel bowl and keep this downward pressure while you fit the collar. Don't allow the fuel bowl to spin because this risks the o-ring unseating. Also be careful not to cross thread the locking collar. You are supposed to tighten the locking collar three ribs after hand tight but one man's hand tight is another man's finger tight. So how I do it is so long as you can't turn the fuel bowl by hand afterwards then it's tight enough.
I always say don't let the fuel bowl spin while you're tightening it up. There is one exception- when it is tight right at the end, it can move a little bit. Theo-ring has pressure on it and it's not going to unseat. Fill the fuel bowl with fuel. I find that it will then find its own correct level. Fit the top cap with a new o-ring.
Check the tension of your wheel nuts. Rotate the tires if needed. Check them for wear, also check the tire pressures. I put 120 psi in the front tires and 90 psi in the rear. Inspect the front hub oil. The correct level is written on the hub cap.
These engines have an electric fuel priming pump. Before you start the engine turn the key to ignition and let electric Self primer prime up the fuel system for 30 seconds before you start it. Before you start the engine make sure it's out of gear start the engine looking at the oil pressure light making sure that goes off within a couple of seconds. Now that the engine is running, go down and have a listen to your belts. Make sure there's no squeaking indicating a bad idler bearing then go and have a look at your oil filters, fuel filters and sump plug. Make sure there is no leaks. Inspect your belts make sure there's no ribs missing make sure that they're in good condition.
Inspect your coolant and boost hoses for leaks. Generally have a good look over the engine. After five or ten minutes go and dip the oil make sure you have the correct level. As a final thing before you finish wipe off all your dirty fingerprints. There's a few things that I didn't film, like filling the auto Greaser, checking the batteries, inspecting the left hand side of the engine, adjusting the brakes and blowing out the air filter
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