The Mercury News Weekend

What ought to get done in a brake job

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By Brad Bergholdt

What in your opinion should a brake job consist of? Onmy cars and truck, I’ve had just the pads replaced, and sometimes the rotors turned or replaced, but never a caliper replaced. I’ve tried a newrepair place, and theywant to replacemy rotors and install “loaded calipers.” Is this overkill or necessary as a car ages? — Sean T.

There are many variables and approaches to this issue.

Let’s say a vehicle is ready for its first brake job at 46,000 miles (front wear sensors have begun to sing, rear brakes still look good). If there are no complaints of pedal pulsation or noise, the rotor surface finish looks good, and there isn’t noticeable corrosion of components, a simple brake pad replacemen­t will likely do fine.

This job would include inspecting rotor thickness, brake hoses and fluid level, and cleaning/lubricatin­g caliper slides and associated hardware. If brake fluid is more than three to four years old flushing/renewal is recommende­d. With premium grade pads installed, the odds of repair success are perhaps 90 percent

The second brake job, let’s say at 90,000 miles, likely includes the rear pads or shoes aswell. This time rotor finish is a little sketchy due to light scoring, glazing or some hard spots. Assuming rotor thickness is sufficient, machining (turning/refinishin­g) them is prudent. Replacemen­t is overkill unless after-machining thickness is too thin. Replacemen­t of caliper attaching pins, seals and so forth should also be considered unless they look really good. It’s best to flush/renewbrake fluid again. Repair success odds, due to additional variables, drops to perhaps 80 percent

At the next brake job (130,000 miles?), it’s possible the rotors have become worn and their surface finish has deteriorat­ed due to heating issues because of their reduced thickness/ mass, causing pulsation or noise. A second light machining may be all that’s possible due to minimum thickness rules, so replacemen­t may be called for. My take on this is a slightly imperfect original equipment rotor may actually be superior to a cheap replacemen­t part. If rotors are to be renewed, step up and buy good ones! Repair success odds vary— see caliper opinion below.

Loaded calipers (remanufact­ured calipers with pads already inserted) are a nifty idea but, I think, overkill unless a vehicle is 10 or more years old, it’s operated in a corrosive environmen­t, or one or more calipers shows evidence of seepage. If the remanufact­urer is QS-9000 certified and the pads included are of premium quality and fluid is flushed/renewed/bled, this is much preferred over rebuilding a caliper or replacing just one. The bottom line is caliper problems are rare, if one maintains fluid condition.

Repair shops obviously want to insure a safe driving outcome and minimize the chance of a comeback, so recommenda­tions to play it safe with additional parts or services is understand­able (I’ll leave profit out of this). Performing a cheapo brake job can become a headache for both parties!

On the other hand, new part quality vs. the “if it ain’t broke don’t fix it” principle is tricky. A while back I renewed rear brakes onmy Tahoe. One drum was lightly scored, and they had a lot of miles on them, so I renewed both. I stepped up formid/upper grade parts and still went through two pairs of replacemen­ts before achieving pulsation-free driving enjoyment.

Brad Bergholdt is an automotive technology instructor at Evergreen Valley College in San Jose, Calif. Readers may send him email at bradbergho­ldt@gmail.com; he cannot make personal replies.

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