On the show, the notion of backing up rapidly and jamming the brakes to reduce squeal was ridiculed. Well, I first heard the idea about 40 years ago, and saw it demonstrated successfully. Hadn’t thought about it since.
I’m guessing that it works by bending or otherwise moving shoes and/or mountings to create a little toe-in, which will stop squeal until the pads wear square again.
What the brothers failed to mention was that backing up rapidly and jamming on the brakes was a somewhat effective way of adjusting brake shoes. It harnesses the tendency of the brake backing plate to twist when the brakes are applied while backing up, and uses this motion to adjust the brake shoes. Ford introduced this feature in the mid-late '60s, and it was rapidly adopted by other car makers.
However, disc brakes are not adjustable, so this does not apply to modern cars with disc brakes. Nowadays, with few cars still having brake shoes (and those few only in the rear), this method is not going to help at all with most cars and will provide adjustment only on the rear wheels on some others.
@VDCdriver - That’s right. It’s the first thing that occurred to me, too, surprised the brothers didn’t put the caller at ease. FoMoCo was still installing drum brakes on all wheels as late as the age of my vehicle, so it’s a method I know well. The ratcheting system is very clever and still seems to work despite some warping in the drums, which tends to pulse braking slightly. What ya know: ABS brakes!
I had a squeal come on rather suddenly and thought it would ruin the rest of a trip. I drove backwards and figure eights and nothing changed. I then remembered a friend talking about getting something out of her wheels/brakes by going to a car wash. I paid my $6.50, went through the car wash, and much to my amazement the problem was gone. I think a stone got jammed and the car wash took care of it. Today’s brake problem that was discussed on your show sounded more long-lived – but mine sure sounded awful and I was about to leave my car for the weekend. Sure glad I went to the car wash!
Years ago I owned a Mazda GLC (Great Little Car). One day, without any warning, there was suddenly a very alarming squealing, grinding sound when I applied the brakes. Because it sounded as if I would damage something if I continued driving, I parked the car and had it towed . To make a long story short, after several occurrences of this event, I realized that I was getting a small stone into the brakes (perhaps a design anomaly of this particular car), which made this terrible sound. I also discovered that the easy fix was to back the car up and apply the brakes. Evidently, this would cause the stone to pop out, as the noise went away every time. Perhaps the caller was not so far off the mark.