Preventive Maintenance: Easier Than Performing Corrective Maintenance

Where should you draw the line on how much to repair?

In the case of an aged fleet, you may be struggling to keep buses road-worthy. Many shops are performing what I call “the corrective maintenance program,” meaning, if it isn’t broken, why spend time on it? They refuse to perform sufficient preventive maintenance (PM) to improve overall reliability. Buses continue to break down because components that should have been repaired or replaced some time ago are now beyond useful life.

Think about it: if you are always fixing things that are broken, you are not doing enough to prevent them from breaking. It is true that components will eventually break, but the reason behind PM is to do all we can to extend their lifecycle and try to calculate a reasonable replacement time before they fail.

It’s important to realize that your present corrective mode of operation has taken years to get to, and that to turn it around is going to take a while as well. However, once achieved, you will end up spending the majority of time performing PM and just a little time fixing broken buses. (Keep a positive attitude about improving. It takes work and time. Nothing good ever comes easy.)

To get started, make a list, placing your buses into one of three columns:

• Column A: Buses 3 years old and newer.
• Column B: Buses 4 years old and older.
• Column C: Buses from column B that will be sold, scrapped, or replaced within 3 years.

Column A: When servicing these buses, repair every defect and potential problem you find. This will keep these buses in premium condition. Now, keep doing so for the life of these buses. They will require the least amount of work on an ongoing basis and continue to be the most reliable buses in your fleet.  

Column B: Buses 4 years old and older will require more work to bring back to optimal condition. When performing service on these, make a list of every defect and potential problem found during the service, as well as all issues previously known to exist on the bus. Review the list before making any repairs to these items. Sort these items into three categories: 1. Repairs that can be completed in less than 10 minutes. 2. Safety-related repairs 3. Non-safety related repairs.

Of the repairs in your “less than 10 minutes” category, move any safety-related repairs to category 2. All safety-related repairs must be completed before placing the bus back into service. Complete as many of the 10-minute-or-less repairs in category 1 as possible. Also repair as many of the non-safety items in category 3 as time allows. Spending too much time on one bus only increases your work backlog.

Column C: The oldest buses will require the most work. These will receive only enough repairs and maintenance to keep them operating safely. If major repairs are required, refrain from making these repairs and take them out of service if possible. The money needed to replace major components would be better spent towards a replacement bus. It is really hard to justify putting a lot of money into a bus that is scheduled to be replaced soon.

The objective is to try to get the bulk of issues resolved at the time of PM. Reviewing this list helps you decide which items to repair now and which to reschedule for a later date. Eventually, the overall reliability of each bus improves, and the operation slowly shifts from corrective maintenance to PM.

Learning how to spot potential problems and analyze the cause and effect of those issues will help you determine why components are failing and guide you to a solution to extend component lifecycles.

Becoming a maintenance expert is really important. For example, supervisors will often place inexperienced employees on the lube rack. Although this is a good place to learn, these employees must be taught that this position is one of the most important jobs in the shop. Doing good work in this position helps the entire operation be successful and efficient.

Brad Barker has more than 40 years of experience in school bus maintenance as a shop manager and technician. He has written numerous articles for SBF. He can be reached at schoolbuspm@outlook.com.