That’s right a tow truck or in this case a trailer with a winch. The tow truck driver admitted he likes using the trailer because of the time it saves. Once hooked on to the axle a winch pulls the bus on to the trailer with very little else to do compared to the conventional method of towing which involves removing the driveshaft, chaining up the rear axle and installing auxiliary lights to the towed vehicle.
With a power steering leak unless the repair can be made in the field contacting the towing company is the only option. The power steering pump on a Thomas school bus is at the rear of the bus engine driven of course and the steering box is at the other end below the driver. The pressure and return hydraulic power steering lines are 35 feet long so repairing on the road is usually not possible.
The hoses have to be removed and replaced. There is a hydraulic shop in town that we always use for hydraulic lines and fittings. They specialize in this area and have any part you need to get the repair done. The oil loss was significant and drained the entire system on to the parking lot so we rounded up a large supply of floor dry which did the job. We don’t want John Q public to think of us in a negative way so clean up was immediate and only took an hour.
Once the bus was on the hoist we found the power steering line was rubbing on an air valve which probably took a long time to develop the leak but it finally happened and caught the driver by surprise. One lucky thing is the power steering oil reservoir holds a large amount and gave the driver some steering action before the system completely drained out.
The important thing with this break down is the steering wasn’t completely lost and the bus was empty. Operators are trained to notice any changes with their bus when operating it on the run. Their eyes and ears help us out so any reports they present on pre-trip slips are taken seriously. In the end the steering lines were replaced and the bus was road tested to operating temperature before returning it to the driver. This goes to show that anything can happen at anytime in the fleet so preventive maintenance and inspection during services are very important.