School Bus Vehicle Inspections and Repairs

Mechanics Hub - February 28, 2014

Motor Vehicle Inspections – A Very Necessary Routine

Every month there are a certain amount of motor vehicle inspections. The average number of inspections runs around 6 -8 per month. There are 66 buses in our fleet so the inspections are spread out over the year. This week being the last one of the month the February inspections needed to be completed.

We had a couple left to do so all it takes is some scheduling and possibly a spare bus for the driver. Included in the inspection is an air test. Compressor build time, air leaks with brakes applied and compressed air reserve. That means making sure the check valves are holding. When the air pressure is lost in one tank the other remaining air tanks must hold without losing air.

The 121 air brake system we have in the school buses are designed to back up the system when air is lost in one tank. There is a test we run to check the 121 system. Draining the wet tank then primary and secondary tank one at a time will tell us if the system is operating properly.

This test will tell us if the check valves are working correctly and their is brake reserve if one of the main tanks are drained. Very important... so if a major air line blows the driver will have enough brake applications to bring the bus to a safe stop.

Yearly Servicing on Major Components

While carrying out the yearly motor vehicle inspection we also do major servicing on components if they are due. The transmissions are 3 years on average between oil and filter changes since we use synthetic ATF.

Our new buses have “prognostics” which does the scheduling for us. Much like the “change oil light” on your car a service light comes on for the transmission telling the operator that the oil or the filter needs replacement.

I did a previous article on synthetic transmission oil which I think will interest you because I NOW am a believer in paying 3 to 4 times the price for synthetic oil compared to the Dexron brand. The benefits are numerous....much more than you may think if you are not yet convinced that the price is worth it.