Brake fluid "eats" paint. Although widely used for many decades, brake fluid is nasty stuff…
Gimme a Brake!
Knowing the “when” is just as important as the “how” with brake system maintenance
Are there oily stains running down your tires’ inner sidewalls? Garage floor puddles not attributable to driveline drips? A low fluid level in your master cylinder? Is your brake pedal spongy or demanding several pumps to slow the car? If you nodded yes to any of these questions, your pride and joy is crying out for urgent brake system maintenance. Take heed or suffer the heartache of making repairs after a nasty collision.
Deciding exactly what to do is easy if you’re in the thick of a frame-off restoration. Even if your wheel and master cylinders pass scrutiny, this is the ideal time to replace those crucial but inexpensive parts. Brake lines showing corrosion or any hint of a leak must also go. Here, it’s wise to upgrade to pre-bent stainless-steel lines, because this is a step you won’t want to repeat, and stainless lasts essentially forever. Rubber hoses are readily available and usually affordable, so retiring ones that are hard, split or swollen is essential. Since vacuum brake boosters are difficult to disassemble, diagnose and reassemble at home, I recommend shipping your vintage part off to a specialist for rebuild. Check with fellow club members for a recommendation, or contact one of the vendors in our resources list. And don’t neglect the parking brake mechanism, cables and friction materials.
Even if you’re not separating your body from the frame, you can still conduct a thorough brake system service. Start by identifying where fluid is leaking. Then use the cut-and splice method to replace seeping or corroded sections of rigid brake line. Unless they’re obviously compromised, your rubber hoses may not have to be replaced. Those handy with tools should be able remove minor corrosion or wear marks from master- and wheel cylinder bores with a hone in preparation for the installation of fresh rubber seals and boots, available from parts stores. Disc brake calipers are another matter. If you find bore corrosion, which is caused by failing seals, the best solution is to have a specialist install stainless steel sleeves to correct this common weakness in early disc brake designs.
Proper tools are essential for removing and replacing brake line fittings. Instead of attacking the job with common open-end or adjustable wrenches, which often round off hex fittings, you’ll need flare-nut wrenches or sockets. These have two additional contact surfaces to grab the fitting without slipping.
In the next issue we’ll discuss brake fluid options and the reassembly and testing phases of brake system maintenance.