20 November 2008
Toyota and Ford
How to Repair Hybrid Brakes
By Pierre Lalonde
Dealing with hybrid vehicles for brake maintenance or repair is peculiar. There are slight differences among manufacturers, which you have to know about in order to fi x the car correctly – not to mention the high voltages present in the electrical system that can be lethal if you don’t follow the safety instructions.
Hybrid vehicles run on a combination of 12 volt and high voltage, which varies from one manufacturer to another. The hydraulic part of the braking system is conventional and requires only common tools. What you have to remember is to stay away from any orange color cable, wire, plastic plug or switch.
Brake-by-wire
Because these vehicles use a brake-bywire system that uses deceleration to recharge the battery pack, the conventional brakes are seldom applied, except at very low speeds or for emergencies. Gripped or corroded brakes parts will then become more common if you don’t modify maintenance intervals.
Toyota Prius
It is very important that you get acquainted with hybrid cars’ start and stop procedures. Hybrids made by Toyota and Ford drive on electrical power at times. The engine can start at any time and, to prevent this, you must remove the key from the ignition switch. This is especially true when working on a Toyota Prius. The car can be equipped with a smart key, which you have to keep at a good distance (about 3 metres) from the car to prevent accidental start up.
 Ford Escape
Note that before start up, the Ford Escape Hybrid will run the pump motor as a regenerative self-evaluating brake system test. This will activate all four lines of the brake system with pressure testing for leaking hydraulic components. It could accidentally crush your fingers, or pop pistons out of the caliper. Ford recommend to remove fuse #24 (50 amp) and #31 (50 amp) in the under hood fuse box, and to disconnect the 12 volt battery to prevent this occurrence.
On the Ford Escape Hybrid, under the
hood, we can see the two pink square
fuses (50 amp) removed.
Safety precautions
You might have to work around high voltage/ high amperage wiring or components. Thus, you must read the safety precautions required, or better stiff, enrol for hybrid training if available in order not to put your life at risk or get seriously injured. Remember, electricity cannot be seen but it’s always there. Most manufacturers use a disconnect or interlock switch to shut off the high voltage power (orange cables) to isolate it from the rest of the car. It is also a must that you buy a pair of high-voltage lineman gloves as a safety measure.
These gloves are specially made to withstand
the high voltages present on hybrid cars.
SOURCE: AUTOMOTIVE CAREER DEVELOPMENT CENTER, USA | 
