Brakes and Braking

[acarlson]

I've been working on getting my '65 Corsa road-worthy. In the process, I've cleaned and adjusted the brakes and replaced the brake fluid. My Corsa has a 2 cylinder Master cylinder. The Corsa stops in a straight line - no pulling left or right. But the effort required at the brake pedal is a lot more then I think it should be. It could just be me. My leg muscles may just like power assisted disc brakes vs old school shoes and drums. So, I guess my question is - is there any way to test the efficiency and performance of the LM corvair braking system besides just running up the speed and stomping on the brakes ???

Alec

[66vairguy]

Manual brakes do require more pedal pressure than power assisted brakes, but within reason.

This "hard pedal" issue comes up often and has been discussed for many years. I drove manual brake cars in the 60's and they stopped with reasonable pedal pressure. In the last decade I've driven a few 60's cars that had very high pedal pressure making the cars unsafe to drive - IMO. There are a number of causes, but the most prevalent is a very hard brake lining material now in use on FLAPS replacement brake shoes. A decade ago a fellow in a club found a brake shop to install a softer lining material and arch the brake shoes to the brake drum diameter (hard to find now). It solved his problem. I live in a big city and found a similar brake/clutch rebuilder that installs a "softer" brake lining and arched the shoes to the drums (that he turned). My brakes work fine - quite capable of locking up four wheels with the application of just one foot/leg and I'm not a big guy.

[azdave]

- is there any way to test the efficiency and performance of the LM corvair braking system besides just running up the speed and stomping on the brakes ???

Alec

Test drive someone else's Corvair or have them drive yours as a comparison?

Are you are able to lock up both front and rears in a panic stop? One of the biggest offenders requiring high pedal pressure is contaminated brake linings. You can also check your brake drum temperatures with a temperature gun. After a few hard stops are the brake drums similar in temperature? That can give clues. If you've only driven power-brake vehicles then going back to correctly operating manual brakes still never feels right (until you've driven a few weeks to get used to the difference).

[acarlson]

Test drive someone else's Corvair or have them drive yours as a comparison?

Yeh, I thought about that. I thought I'd check with Brad Bodie - he lives about 50 miles from me but I'd have to run some twisty mountain roads at high elevations to get there. I'm not ready to test my brakes on that yet.

Are you are able to lock up both front and rears in a panic stop? One of the biggest offenders requiring high pedal pressure is contaminated brake linings. You can also check your brake drum temperatures with a temperature gun. After a few hard stops are the brake drums similar in temperature? That can give clues.

Checking drum temps is a good idea - I'll give that a try. The brake linings are fairly new - probably less then 1000 miles on them.

If you've only driven power-brake vehicles then going back to correctly operating manual brakes still never feels right (until you've driven a few weeks to get used to the difference).

Haven't driven manual brakes since the late 60's and early 70's. As I said, it could just be me - I just have nothing to compare with.

Thanks - Alec

[66vairguy]

The brake linings are fairly new - probably less then 1000 miles on them.


You can pull the drums and see how the new shoes are wearing. If the arc is off only a portion of the show lining will show wear.

If so then the shoes need to be arc'd to the drum (difficult to find a shop now) or your stopping ability will not be good.