When The Rubber Meets The Road

I share this because accidents, incidents or events in general are never the result of a single decision; rather they are the culmination of a number of factors that line up to create that event.  Sometimes the outcome is fairly benign, while other times it is a full on incident or accident.  
Nobody gets up in the morning deciding they are going to make a decision that results in one of these events and the best we can do is be on the lookout for things that can make a poor decision not become a bad one.

When we purchased the RV we had to install a supplemental braking system in the car to be able to tow it behind the RV.  By law in Ontario you need a braking system in the vehicle being towed, and as cars already have them you simply need a way to activate the brakes proportionally with the brakes in the coach.  This coach has two methods of supplying the signal to the car - with an electrical impulse, or using compressed air.

The air system is the simplest to hook up as you simply connect the two tow bars, the cable for the lights, the safety chains and an air line to the air system that already exists in the coach.  On the car end is a device that translates the air pressure from the coach to a cylinder that is attached to the brake pedal in the car.  This is the easiest to set up but the most expensive option to buy and install as it is permanently installed in the car, so if we change cars we have to do the install all over again.  

Second option is the one we went with and is a small box about the size of a shoe box with a physical connection to the brake pedal that uses logic to determine the amount of force to apply to brake the car.  This is a bit of a pain in that you have to install and remove this box every time you are towing, but you have the benefit of being able to take it with you into another vehicle.

The braking system was purchased and installed by the dealer who sold the RV, and although we had only towed the car once up to North Bay it seemed to work well.  When we left North Bay in early October we again towed the car down to Kitchener to leave it there for a week while we continued on to a training course.  The manufacturer of the chassis (Spartan RV Chassis) offers a five day training course for owners of RV’s equipped with their chassis.  When we purchased the RV we wanted to be as knowledgeable as possible on the systems and components that were part of the chassis, so booked a training course for both of us in early October.  I will write more about that in another post.

One of the things we learned in the course was to not drive the vehicle with the Engine Brake on.  Rather, only use the engine brake when going down steep grades.  This RV, like most diesel coaches, has a feature similar to big transport trucks whereby you can use the engine as a way to slow the vehicle down.  I am not at all technical so will not try to explain the full operation on an engine brake, but basically when you use the engine brake the engine does not ignite the fuel air mixture on the compression stroke in one or more cylinders so in effect uses that compression to slow the engine down.  Mistakenly, most of the attendees on the course did not know you shouldn’t be using the Engine Brake and had, like us, been using it all the time thinking we were saving the brakes on the coach.  These vehicles are equipped with very heavy duty brakes, and for the amount of miles grey-haired RV users will put on the coach in their lifetime it is extremely unlikely to ever come close to wearing them out.  In fact, they said if you use your Engine Brake all the time you are not generating enough heat during braking and can develop problems on the disc or drum lining.  So, we left the training course with the engine brake off and were happy knowing we were using the brakes properly.

In early November we hooked up the car to begin our trip south and all went well.  The car is a 2023 Ford Escape Hybrid and one of the things you need to do is put the car in Tow Mode and leave it in that mode for at least ten minutes prior to moving the car.  We have been doing that all along and this apparently is a requirement to allow the car electronics to ‘go to sleep’ while it is hooked up to the coach with the transmission in neutral.

We departed Kitchener and drove the three hours or so to Windsor with only very minimal braking and no issues.  If you know Windsor and the 401 you end up on an eight lane city street for the last few miles before the border.  Coming up to a stoplight the light turned yellow and I applied brakes normally to stop.  At that time I heard the brakes on the car screeching and could see blue smoke in my side mirrors.  We stopped and when the light turned green proceeded with no apparent issues on the car.  Two more stop lights later and the same thing happened.  So for the rest of the trip I reverted to using the engine brake until I could determine the problem.  When we got to destination I looked at the tires for damage and found minimal scuffing in two spots.  Then I looked in manuals and reached out to the brake controller manufacturer for assistance.

The next day was to Cincinnati and so all highway driving except the last few miles.  Same thing happened with no problems until we were in traffic with a stop every few lights or so.  I inspected the tires and began to see some definite wear marks.  As we were stopped for a few days we unhooked the car to tour around.  As soon as we got in the car we could tell there were flat spots on the tires.  I then tried the manufacturer again and also sent an email to the dealer who did the installation as this was now a real concern.

When it came time to depart Cincinnati we were headed once again on the freeway with minimal braking, except for a planned fuel stop in Kentucky.  When I applied the brakes turning into the fuel stop the brakes locked up and I could see the skid marks extending for what looked like 100 feet or so.  This was becoming alarming so I disconnected the electronic brake system and carried on until I could hear back from the manufacturer or dealer.

The next day I did get a call back from the manufacturer and through some questions and answers was able to determine the configuration the dealer set up for our car was for the wrong type of vehicle.  I dont know which cars use which type of braking but I was told that hybrid cars (at least the Ford Escape) use Active Braking as the method of applying the brakes, versus a Vacuum system.  When the system was set up at the dealership it was configured for a vacuum braking system.

What this meant is the brake pedal application was sometimes close to full deflection on the pedal which locked the brakes.  The brake controller manufacturer told me to change the setting to Active and start off using 10psi as the application pressure and guaranteed I would not have any further issues.  I did that and the system has worked fine since.  We monitored the condition of the tires at each stop thereafter and made a decision by the time we got to Phoenix to replace the two front tires as the deterioration on the flat spot was getting more pronounced.  

Unbeknownst to me at the time, when brakes are applied on a car, it is the front wheels that brake first and the rears second, so there was no issue with the rear tires.  I also learned from the discussion that once a flat spot is on a tire it is more likely to be the spot the tire locks up on the next time, so it will only get worse.  

After all was said and done I may have been able to continue with the tires but it was only a matter of time before something would happen that would make for a really bad day.  I have a tire pressure monitoring system on the car but if a tire bursts on the car while being towed it is not likely I would even feel it so would cause significant damage if it were not stopped and changed.

So back to the start of this entry - a number of independent decisions were made that did not have the ability on their own to cause the problem, but the combination did.  The dealer may not have had much exposure to hybrid vehicles and so the technician installed it the way standard vehicles are configured.  My initial use of the Engine Brake disguised the fact the dealer had set up the system incorrectly.   Also, with the car being hybrid the configuration was different than other cars and I have notified the dealer to change their installation procedures to ensure hybrid vehicles are set up with Active braking for this particular braking system.  I did reach out to the dealer with all of this and they agreed to reimburse me for the full amount of the two tires.  That was a decent thing for them to do and I am pleased we were all able to learn something without any major problems.