With any type of drum brakes, before any adjustment is done, all previous adjustments must be undone. Meaning that, if you want correct brake adjustment you should assume that a dickhead has worked on it before you and that it is wrong.

First thing that should be done is to back the handbrake off fully. Because it is possible for the handbrake to be already applied and causing adjustment problems. The amount of times I've had to slap apprentices for adjusting the rear drums through the handbrake is beyond what I'd like.

Once the handbrake is backed off you can adjust the rear shoes. The correct way is to adjust the 'Dust Free' shoes until the rotating assembly binds and then back them off 4 to 8 clicks. When the other side is adjusted you must do it the same to prevent an uneven brake adjustment.

Manuals don't tell you everything you need to know. They are written by people who have never actually worked on something older then 20,000KM. They are a guide only.

I never heard of "poor quality brake fluid", let alone causing this problem.

All fluid is in-compressible. Some guys use water with soap or something in it (bush mechanics). And the brakes still work!

Did you tighten the brake adjust until the tire wouldn't spin by hand, then loosen it a touch? Try it, i always get a "high and tight" pedal this way, with B110, B210 or B310.

Another thing is when you first apply the brake pedal, while it has been sitting for at least 30 seconds is it hard or does it go near the floor? For arguements sake, if you first apply the pedal it goes 3/4 down then the next immediate pumt it only goes 1/2 way down then you have a brake adjustment problem. Combined with this, if your handbrake feels like it is correctly adjusted then the handbrake is most likely the problem.

@DDgonzal, thats exactly how I re-adjusted the drums. The brakes used to feel great, where I could barely tap the pedal and the brakes would start to tear your face off. I drove it an hour out to take my GF to a movie audition, and since then it's never been the same.


@revhead001, It's very inconsistent, however I can let it sit for any amount of time and it doesn't stiffen up. It's almost always straight down towards the floor. How would the handbrake adjustment effect the foot brake?


With that, here's some added info.

I find (very strangly) that If I drive the car hard, up to 5K before shifting, the next time I jump on the brakes, they're stiffer and feel better. Kind of strange, because I've blocked off the booster to confirm that wasn't the problem, and it still acts the same.

Also, I have noticed that when driving on flat ground, if I go over onto a steep downwards hill, even if I'm on the brakes, I loose a lot of braking force. This, to me, sounds like air in the line, but I've bled AT LEAST 1 gallon of fluid out of the car assuming it had air.




Is it possible the proportioning valve is problematic? Or that I have an air lock in it? I did replace a hard brake line leading from the master to it.

OK before you do anything else you need to hook the booster back up

Tom

Well metalmonkey47 you have us truly stumped.
Now it is time to start changing parts until it starts working.

Can't be air in the lines, or it would never be a hard pedal.

Could it be swelling brake hoses?

Rally- I've already got it LONG hooked up. It was just temporary troubleshooting ;)


DDgonzal- They weren't when I looked at them, but I suppose it's possible that as they heat up and soften, they might? I've been looking at making a camera mount for the wheel wells so I can use my cheap camera and watch the brakes as I drive.

All new brake hoses are in the mail today and should be here soon.

How did the new brake lines go. Mine is doing the same thing. Arrggh.

Metal Monkey, if you haven't already make sure you get the brake line at the back that goes from the drive shaft tunnel to the rear axle............these get forgotten on live axle cars. My original thought was the hoses, hopefully this fixes your problem.

I'm feeling your pain............I went to Friday night practice at the Kart track and during the 3rd session the pedal floated down to the floor, I spent Saturday getting it sorted and the Kart only has a single master cylinder one caliper....mighty-vac did the trick.

Tom