Putting the Brakes on
By SAM SMITH
Safety Fast may have been MGs motto, but reliable stopping power should be every British car owner’s top priority. A car slows and stops when its kinetic energy is changed to heat energy. That happens when you pressurize the system with your foot and bring the friction surfaces of the brake pads and shoes into contact with the rotating parts of the brake system, the shoes and rotors.
Age, heat and pressure put a lot of stress on brake systems. Pads and shoes wear out, cylinders and calipers start to leak and the last thing any of us want is to have our cars laid up awaiting repairs while the sun is shining.
Here are a few tips for monitoring the whoa system and keeping costs down by catching problems early on:
- If you hear any metal to metal or grinding sounds when applying the brakes, get service as soon as possible. Those sounds indicate the front brake pads have worn down to the metal and are eating away at the rotors or the rear shoes have worn down to the rivets, which in turn are eating into the brake drums. On many vehicles the brake rotor or brake drum is thick enough that a machine shop can remove a thin layer of metal, making the braking surfaces smooth again. If not, the brake rotors or drums will need to be replaced. Smooth surfaces maximize friction and stopping power.
Replacement rotors or drums are also almost always required should these surfaces become uneven or lumpy due to wear or heat. One sign of this needed replacement is if the brake pedal under application pulsates under your foot.
- If your cars happens to need towing for some reason, gently advise the flat bed operator to use caution while securing the car by setting big hooks over the rear differential. The rear brake lines run along the differential from the center to the wheels and will be crushed. These lines won’t usually leak but the rear brakes won’t work either. It’s an area we always look at when checking over a car.
- Pay attention to the brake reservoir fluid level. Check it often – weekly, monthly whatever fits your routine. Translucent reservoirs are as easy to check as opening the bonnet. A small drop of the fluid level over time is normal as the front pads wear down but a sudden drop in fluid level should be checked out. Leaks are usually quick to spot. Look for the wet spot under the car or in the case of the master cylinder, check the carpet under the driver’s feet. Master cylinder issues can occur without leaks should the internal seal start bypassing fluid. The brake pedal may go all the way to the floor or just halfway. Another symptom of leaks is the pedal just keeps going all the way to the floor when you press firmly and steadily on the brake pedal.
- Sticky Brakes. Before replacing those expensive front brake calipers and rear wheel cylinders inspect the flexible brakes hoses located front and rear. Most cars have three, one for each front wheel and one serving the rear brakes, but some models will have flex lines at each rear wheel also. These lines deteriorate from the inside out and a collapsed flex line will not allow the brake to release correctly. You can tell if the brakes are still on when your foot is off the pedal by feeling for a hot wheel after a short drive, or because the car doesn’t roll on a slight incline at a stop sign or red light.
- Pulling and reduced braking performance can be the result of a failed rear axle seal which has allowed the rear differential gear oil to leak out and soak the rear brake shoes. Replacement of the rear brake shoes and the rear axle seals is recommended.
Should brake trouble ever develop in your car, knowing what to look for and relaying causes and symptoms to the servicing technician can save you time and money.