Week 8

This week I got a chance to remove and install a set of 10 lug dual wheels from one of the buses

This is a 2009 Duramax engine. The bus about 100k on it and had a code for a faulty egr valve so I got to replace the valve. This job would have probably been a lot easier if this was a pickup truck but since the engine is in a van style bus the engine is crammed in there. The egr valve is located right next to the turbo on the right side of the engine. To get the egr valve out the air intake had to be removed along with the serpentine belt and the alternator.

On the left is the air intake and that is the passage way that is coming from the egr valve. It had alot of soot deposits on it from the recirculated exhaust. Then on the right is the air intake tube all cleaned up.

This is the egr valve, the passage ways were all filled with soot. These new diesel engines have really clean emissions but it causes the inside of the engine to be dirtier.

There wasn't much room at the back of the engine either. Some of the exhaust had to be taken apart to remove the egr cooler so that it could be cleaned because its was also half way plugged up with soot.

This week =32, total =236

Week 7

This week I got to help out rolling in some new main and rod bearings into a cat 3116. The engine was making some noises when reved up. It was also know that it had been ran low on oil a couple of times and it was also gonna get a new oil pump, which is supposed to be an updated pump.

The first bearing we replaced was the thrust bearing. To get it out we used a trick one of the guys had learned where you put a small roofing nail in the oil passage on the crank and turn the engine over by hand and the bearing will spin right out. We were only able to do this on the thrust bearing though because it was the only one with an oil passage but the other bearing were fairly easy to get out.

The thrust bearing ended up showing a lot of wear on it. The thrust bearing didn't want to slide back in very easily so we had to use a pry bar on the counter weights on the crank to slide the crank side to side to get it lined up to slide the thrust bearing back in because of the extra surface area that the thrust bearing has.
The rest of the install went smooth. The other bearings all had some wear on the. One unusual thing that was noticed on the rod bearings was that they all had a wear spot on them in the exact some spot on each bearing.

The torque spec for the main caps was 45 ft/lbs and then you turn the bolt another 90 degrees. The torque spec for the rod caps was 45 ft/lbs and the you turn the bolt another 60 degrees.
After the install the engine noise was gone.

 

This week =46, total =204

Week 6

This is an idler puller on the belt tensioner for the belt that goes to the fan clutch on a cat motor. This pulley has about a 1/4" groove worn into it from the belt. It was believed that the tensioner was worn out causing the belt to not ride straight across on the pulley causing excessive friction on the pulley and wearing a grove into it. It probably didn't help it either that the fan clutch was also stuck on putting more strain on it.

 

I got do some wiring hooking up some brake lights, these brake lights don't have connectors so the wires have to be crimped. These lights were also LED so all the little bulbs in the brake lights have to work or they have to be replaced. We also replace all lights like these in pairs so even though the other brake light was still working it got replaced anyways.

 

We also did a lot of seat covers this week replacing any worn seat cover, damaged seat covers, and the foam pads inside the seat covers. Seat covers can make for a long day.

This week =40, total =158

Week 5

This week I did two more valve adjustments and that finished off our list of busses that needed valve adjustments for now. I also did some more LOF's on some of the smaller busses. They were newer buses so I didnt find any problems or things that needed repair on them.

I learned that a common problem that busses have is water leaks inside of them. All of the seams and all the lights can eventually develop leaks, which is sometimes due to driver error when they hit stuff. To find the leaks we blew air around the lights and seams and someone would sit inside the bus and listen for air coming through. So we got to spend some time taking off light and resealing them with silicone.

                                                   Fuel filter on an International dt466

 

This week =40, total =118