Good brakes a distant dream

Say what you will about a vehicle that has a lot of power or one that gets great gas mileage. I like a vehicle that has great brakes.

Despite my going off about all the improvements being made in the most recent automobiles. I think real braking improvement is sadly lacking.

When you get a vehicle with great brakes it is something to rejoice about. In our neck of the woods, we spend a lot of our driving time with our foot on the brake pedal. As a result, a big part of my business is working on brakes.

Can I take a vehicle with a mediocre braking system and have it leave my shop with a great braking system?

Not likely. A great braking system is more than the sum of its parts but starting with great parts will ease the path to overall greatness.

Great brakes are all about feel. The first set of great feeling brakes I really noticed were on Acura Integras of early ‘90s vintage. Step on the pedal and before that first inch of motion the brakes are applying and slowing down the vehicle.

The pedal feels firm but the brakes do not grab and threaten to throw you through the windshield. They are the epitome of linear. Push a little harder, slow down a little faster.

Great brakes feel just as good on the first application (like Wedding Cake corner) as they do slowing down to 50 km/h before entering the Gulch.

Your braking system has to be more powerful than your engine and all that power makes heat. The brake components must be capable of shedding all that heat.

In order to do that, they must have enough mass. If the heat cannot be handled, the linear pedal feel at the top of the hill will diminish as brake fade (pushing harder gives no increase in deceleration rate) takes                                over.

So, yes, size does matter. Big brake rotors help shed more heat. The brake pad material factors big in the overall brake performance.

The brake pad is squeezing the rotor creating friction and making heat. A steady friction coefficient between brake pad and rotor while temperatures are rising again gives that linear consistent feel.

The calipers squeeze the brake pad against the brake rotor. A stiff strong caliper transfers the force from your foot on the pedal directly through the brake pad to the rotor.

Unfortunately there are a lot of pieces that affect brake feel that are between your foot and the caliper. Unless all these (brake hoses, master cylinder, antilock hydraulic unit, brake pedal mechanism) are optimized, the end result could feel mushy, slow reacting or maybe even grabby.

So maybe most of us (me included) do not have vehicles with great brakes. We still need brake systems that are the best that they can be.

One of my pet peeves are brakes that shake the steering wheel in your hands and pulse the pedal at your foot. This is not normal brake behaviour.

When your brakes are exhibiting this symptom it is time to seek repairs. A professional repair should eliminate this symptom and keep it from rearing its ugly shake.

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Trail’s Ron Nutini is a licensed automotive technician and graduate of mechanical engineering from UBC. He writes every other Thursday. E-mail: nutechauto@telus.net