[Brady]

This is what I found on my bus after I learned the extensions could be a problem.

Davy

[Archived]

I have had the sensors leak , there is a seal inside there they can go bad you can replace seal if you call pressure pro they will send you new ones , my rule of thumb is do not screw with the tires unless you are some where you can work on them, one time checked pressure on a front tire with a fill thru cap and it screwed up and let some air out , it got stuck it was on my big truck

[Peter]

Davy beat me to it. I was going to post photos that showed the same thing. And the stems were supported with the grommets that are supposed to stop the strain and flexing. They do neither.

[Archived]

This is a great thread with tons of important safety info. Getting back to the tire fire diagnosis, failure to maintain the hubs can also be a source of fires. There was a castastrophic accident during the evacuation of Galveston in advance of hurricane Rita in 2005 in which an MCI bus was driven without lubrication in a tag axel bearing. As the bearing broke down, heat from the friction ignited the tire and then quickly the whole bus, resulting in the deaths of 23 mostly elderly and handicapped passengers. You can read the NTSB report of the incident on the net. Google MCI Bus Fire Report and you will find it. (Sorry, but I’m unable to post a link.) Anyway, while you are down there checking your tire pressure, make sure you also check the hubs.

[Archived]

Bryan has raised an excellent point and one that two Prevost owners have had some unfortunate experience with.

Our wheels and tires need to rotate freely. This thread emphasizes the dangers or running on low tire pressures, which has led to a discussion of other wheel and tire issues that can expand to become much more serious problems.

Dragging brakes and hot wheel bearings will also have very serious consequences. On two occasions Prevost owners had service work done on their hub seals on the drive axles. In both cases the mechanics did not take the necessary steps to insure the bearings were provided with gear oil from the differential, so after the hub seal repair the coaches were returned to service, and within a relatively short distance both coaches ended up with siezed bearings which got so hot the end of the differential housing failed. Fortunately neither coach had a fire, but in one case the coach axle began to separate from the coach on a bridge with no shoulders resulting in a massive traffic issue.

The point being that it is a good practice to use the IR thermometer gun to read the temps of all tires when you pull into a rest area, but to also read the temps toward the center of the wheels. Brakes can drag and bearings can fail so if a temp is out of line with all others it usually is an early indicator something is going wrong. In the case of a hub seal service a dry bearing has a life of only a few miles so the only defense in that instance you need to irritate the hell out of the mechanic asking him to verify that after he replaced the hub seal that he not only took steps to insure the bearings were lubed by either filling the hub, or tipping the axle or packing the bearing with grease until differential oil could refill the hub.

In case Bryan’s post left you wondering how a tragedy as described could happen try to understand wheel bearings are highly stressed and they need constant lubrication. On coaches without permanently sealed steer and tag hubs the bearings run in an oil bath. You can check the oil level by looking at the hub cap which has a line on the clear plastic part to indicate the oil level. If you have your coach serviced by others and you do not see evidence the hubs were checked you need to have a chat with the service manager. Usually there will be dirty fingerprints on your polished caps. The drive axle hub bearings get their lube oil from the diferential oil that flows into the hubs as the bus leans left or right. That means it is critical to maintain the differential oil level and again if you have someone do routine service on your coach your mechanic has to include a check of that fluid level as well.

When everything is right life is good, but even when there is a problem of seeming inconsequence like low differential oil level things can get very bad, very fast.