To a fault, I'm as incredulous as they come. And at my ripening age, much as I'd like to, I don't think I'm going to change much. I seriously doubt everything unless someone, something or I prove it differently. Today's soliloquy is about such a time recently when, honestly faced with no other choice, I proved my previously held notions to be incorrect as I resorted to what I thought was the most ridiculous method of bleeding brake lines I had ever seen.
This whole thing started when I was test driving the '77 after yet another alignment adjustment on the recently rebuilt front-end. I noticed the usually awesome brakes didn't have quite the "bite" or grab they usually do. Turned out the re-manufactured caliper I had on the right rear had failed. Tell-tale was a faint film of brake fluid on the rotor; it wasn't gushing fluid, just enough of a leak to inhibit the right rear brake from engaging fully and properly. I replaced the caliper immediately under lifetime warranty from Autozone.
Replacing the caliper wasn't a big deal but if you've ever done it, bleeding the brakes, most certainly was. In the past my wife has been my faithful albeit begrudging assistant and she was far from enthusiastic about being so again. She scoffed at my telling her it would take "five-minutes" as she knows what a pain in the tail pipe time-suck it can be.
We've never "failed" before but this time we unapologetic-ally did. Our communication broke down repeatedly and the master cylinder draining out, that was on me, didn't help either. I threw in the oily rag after about an hour of my, what she claims my, "barking directions" to her to push the brake pedal down and then release it as I opened and closed the bleeder valves. Only thing to show for it was more than a quart of Dot 3 brake fluid wasted. Stuff is not really expensive at $8.99 a quart but when you go through it like I can, it does add up.
Crestfallen but with resolve as steely as ever, I let the earth cool somewhat before I decided to try "gravity bleeding" the system as outlined in this DIY video from a gentleman who calls himself, "Corvette Hop". What did I have to lose beside another quart of brake fluid? If this didn't work, I figured, I'd just take the damn thing to a shop and have them do it. The front brakes still worked well enough to make a short trip.
Gravity bleeding is, as the name implies, where you use gravity to literally pull brake fluid through the lines. The pulling of the fluid, theory goes at least, also pushes out air that's trapped in the system. So simple sounding that there's no way in hell this would work, right?
The master cylinder is always higher than the calipers or cylinders on drum brakes, but I didn't leave anything to chance. I jacked the front up much, much higher than the rear, placed catch pans under the rotors, topped off the master cylinder and opened all four bleeder valves at the same time on the two rear calipers. Yes, third generation Corvette's with the original spec calipers are four-piston jobs and have two-bleeders each.
I let everything bleed for more than half an hour keeping a close eye on the fluid level in the master cylinder topping it off constantly so it wouldn't drain out completely. Afterwards, I topped off the master cylinder (hopefully for the last time), put the top back on it, closed the bleeders, wiped everything down with brake cleaner, put the rear tires on, jacked it all down and, hoping for the best but prepared for the worst, went for a ride.
I knew something was up, in a good way, when before I turned the engine over the brake pedal felt as solid as a rock. I started the engine and I knew I was in a for a nice surprise when I went to shift into reverse and the brake pedal still felt solid. Could it be this method worked?
Much to my sheer delight if not flat-footed astonishment, it did. The brakes bit, dare I say, harder than ever. Son of a gun, gravity bleeding worked! And worked beautifully and with little to no stress at all. While my wife wasn't fazed or impressed at all, she was at least grateful that she'd never have to help me bleed brakes ever again.
As they say, "if at first you do succeed, try to hide your astonishment".
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