Drive it forever: Change your brake fluid often

Dear Mike: My 1999 Honda CR-V with ABS owners’ manual indicates the brake fluid should be replaced every 45,000 miles or 48 months. Is this really necessary? I’m going on 85,000 miles and 75 months in Wisconsin and Florida climates without changing the fluid, with no apparent problems!

Mazda — and I suspect other manufactures as well — doesn’t require changing brake fluid. So why Honda? What happens to their fluid over this time? What is it that makes their fluid fail?

And if replacement is necessary, is there a better brake fluid available? In years past I’ve heard that a silicone or some such brake fluid is superior, albeit expensive. What do you think?

A: I recommend changing brake fluid every three to four years, especially on cars with ABS.

The fluid accumulates atmospheric dirt, wear particles from the brake system and, worst of all, water. All of these things are bad for very expensive ABS controllers. Use only the recommended grade of fluid — in this case DOT-3 — from a freshly opened can.

Silicone fluid should never be used in an ABS brake system; it’s too viscous. It’s popular with racers because of its very high boiling point, and with car restorers because it doesn’t absorb moisture from the air. Changing over to silicone requires complete disassembly or replacement of every component of the brake system that is wetted by brake fluid.

Dear Mike: I have a 1977 Oldsmobile Cutlass Salon with a V-8 350 engine. I just rolled over the hundred thousand mark and I think my car is about to confront me with its first serious old age-induced problem.

I do a lot of highway driving and I’ve begun to notice a rhythmic vibration at speeds of 60 miles per hour and above. The entire body of the car thrums every 2 seconds or so and the problem increases with more speed. Shifting the transmission into neutral and letting off the gas does nothing to abate the vibration, only slowing down to 55 miles per hour or so helps.

Local shops all have different answers and I was hoping you guys could lend me a hand. I just recently replaced the engine mounts, as they had disintegrated with age. But there has been no change to the vibration.

A: You have at least two out-of-round or out-of-balance tires. The rhythmic thrumming is the beat frequency between the tires.

Dear Mike: In May 2006 I purchased a 1995 Toyota T100 pickup. It was supposed to be a one-owner car that had never been out in the winter, as the owners spent winters in the Southern states.

I would like to check the computer out to see if it has been tampered with but can’t find a place to do it. As a matter of fact, I would like to check the whole vehicle out. I am sure that the mileage has been tampered with.

Can you help me?

A: The Web site http://carfax.com will tell you if the vehicle has been rolled back or has been in an accident.

Dear Mike: I have a 2004 Ford Focus with a 2.3 liter I-4 engine. On page 207 of my owner’s manual — where part numbers are listed for fuel filter, oil filter, battery, etc. — it says the air filter is designed as a “lifetime” part, and states: “Non Serviceable Part. Air Filter Service Minder indicates if service is needed. See dealer or qualified technician for replacement.”

My question is how is this filter different from a normal air filter so that it can last a lifetime? And when and if the time comes that it needs serviced, how will I know and what will it involve?

A: Further spelunking in the shop manual uncovers the fact that the air-cleaner element is $381 and is rated for 150,000 miles. This, in spite of the fact that the maintenance schedule, on a different page, calls for it to be replaced at 30,000 miles.

Must be made out of unobtainium, especially at that price.

It takes only a few minutes to pull it out, so I’d just inspect it every year or two.