by Bill C. -
Disc Brake Diaries
Or “How Bug Disc Brake Conversions Sucked My Brains.” You know… I hate messing with brakes, especially making brake adjustments on my Verty (Bug convertible), mainly because those adjuster cog wheels are always frozen up.
So my little peanut brain says, “Why not just convert to disc brakes? No more adjusting and better stopping power! You’ve done the whole gambit on Lightnin’. Should be a cake walk.” Famous last words!
I am writing this because all disc brake conversion kits are NOT built the same. What you don’t know can hurt your brain and affect your vocabulary.
If it were not for the fact that I need to get this newsletter out, I would probably still be out in the garage, blessing out the manufacturer, a famous aftermarket parts company (E__I). You see, years ago, when Lightnin’ was treated to discs, there were FEW kit manufacturers and only ONE that made a kit for the rear that included emergency brake. At that time, I was either lucky or managed to get parts that would actually fit properly. Not this time around, though.
A couple of months ago, I should have stopped as soon as I opened the box and noticed there were NO INSTRUCTIONS! Not even a piece of Charmin. But, no, not me; I could figure it out. I’m experienced! The old parts were coming off fine. I was figuring out what to do with most of the new parts. Just a few hiccups along the way, like stopping to go buy new front wheel bearings after finding the old set felt sloppy after getting the new rotors installed.
But it all came to a head when I bolted on my polished 8-spoke (EMPI) wheels (one of the most commonly used custom wheels on the market) and they WOULD NOT TURN for LACK OF CLEARANCE at the caliper!
“Oh, maybe that washer is in the wrong place. Move it and gain a fraction of an inch.” Well, yes, but now the caliper tries to gouge the rotor! What? Maybe a THINNER washer! Okay, but now I don’t have wheel clearance. Last resort was a grinder on the backside of the wheels. Don’t use a stone, though. They are slow and clog up. One of those air drive cutoff style grinder/cutter wheels works best.
Then this last weekend I had a few hours to spare so I took a nose dive into the REAR brakes, from the same manufacturer. This time I had instructions; as lousy as they were and incomplete as I would later discover. They had one picture of some components, not listing which were in the kit or which you should already have. Nothing on how things should be bolted on.
I’m going to jump to a list of bullets that will help you save your brains on these rear brakes:
· You will need LONGER BRAKE lines or “extensions” that will bring the length of each side to about 30.”
· Brake lines have different ends. Get the kind with the conical (cone shaped) ends.
o Though not identified as such, this mfr. includes 2 adapters to convert from the line’s 10mm x 1.0 threads to 10mm x 1.50 threads (freak) in the calipers.
o Use the copper washers and tighten ONCE. Removal and reinstallation will ruin the seal of the copper washer.
· The emergency brake cables included will probably be about 3” too long.
o These are the last thing to get installed. So test install one while the parts store is open, or suffer the consequences.
o The consequence is either doing without and finishing later or… fabricate a spacer from ½” conduit; cut approximately 3 ½” - 4” long and slide over the nipple protruding from the frame, the other end receiving the cable jacket/shield. Tension of the properly adjusted parking brake will keep the spacer in position.
· Allow plenty of time to BLEED the ENTIRE BRAKE SYSTEM. Start at the front right, then front left, then rear right and finally rear left.
o TIP: Use a clear glass jar with a few inches of brake fluid in it. Insert the bleed tube from the bleeder valve into the fluid in the jar. IMPORTANT: Now, don’t be timid when opening the valve while your helper holds the brake pedal down. Open the valve at least ¼ turn. Otherwise, all the air will not escape.
· If you feel you still have air in the system (have to pump up the brakes), let them sit a while and repeat the bleeding, being sure to use the tip above (1/4 turn).
· Pointer: If your master cylinder was good before the conversion, it is probably still adequate after. You probably have air in the lines, if they have to be pumped up.
Finally, since you are doing a conversion from standard parts and equipment to custom parts, always allow extra time and expect to run into weird problems. Be sure the parts store is open, too. I’m happy to say that Verty has some GREAT brakes now that will put you on the windshield if you are not careful. LOVE IT!