Sunday, May 31, 2009

Brake rebuild, new 30 year old mirror

I have been pretty busy doing work on the '58. The brake master cylinder was leaking real bad when I got the car. So basically, no brakes. I have been weighing lots of options for repairing this, most of them centered around upgrading the brake system as well. I was pretty set on going for a brand new front disc brake conversion with a power boosted dual master cylinder. This would be a really fantastic upgrade, but it would run about $500. My last $500. I was about to settle on a new stock master cylinder ($100) when I found a rebuild kit for only $20! This is the stock master cylinder, rebuilt at home. I disassembled the unit, cleaned it thoroughly, and honed out the bore. I found that the compensating port (sort of a bypass port) was completely clogged and the bore was filled with gooky gunk. I assembled it with new parts, filled it with new fluid, and bled the air out. So far, so good; no leaks. I mounted it back on the car without even repainting it. Two things:
1. People, you can put all the teflon tape you like on the threads of the main brake line fitting (that's it there coming out and going to the right) but THIS WILL DO NOTHING. Brake lines seal by the compression of the cone on the line sealing against a conical seat. The fitting's threads just provide the force to accomplish this, they do not seal anything. This is not house plumbing. The previous owner clearly did not know this.
2. Normally bleeding brakes involves forcing fluid all the way through the lines to expel any air.
In this case, since only the MC was leaking, there should be no air anywhere else in the brake system. The only air should be right at this same fitting. I used a trick I learned from my brother Dave. I left this fitting slightly loose, and had an assistant pump the brake pedal. This forced fluid out of the fitting, but it pushed the air out as well. By catching the forced leak with some rags, we were able to bleed the air out right at this fitting, and we did not have to bleed the entire system. This worked great, and the pedal feels rock hard. I think we have brakes.

I needed an outside mirror. The reproduction stock ones are expensive, and I'm not sure I like the look of them anyway. I bought this replacement mirror at K-mart about the time I had my first car. I don't know what it was for, since I clearly did not use it on that car. Now I have had it, still in the box, ever since. Didn't think I'd ever use it, so I have dutifully brought it to every swap meet I have ever vended at, and nobody ever bought it, for like five bucks. It must be destiny, so I dug it out and installed it, a brand new, 30 year old, five dollar, K-mart mirror. See, you cannot buy that fun kind of history if you buy a car that already has the mirror on it. I like it. Oh, the extra hole was already there.


Finally, for no reason, I'll show you this pic of a dog taking a ride on a '58 Impala convertible. Photo: The HAMB, of course.

1 comment:

Kieran said...

I like the picture of the dog.