2nd Chapter_63 brake bleeding challenge

[Steve D.]

Thanks for the responses. The line to the rear is still blanked off. Since last nite's post I have: 1) checked to make sure that brake shoes are being deployed against drum when pedal is pressed; yes they are, and there is no leak from the wheel cylinder. 2) with power bleeder, bled right front again to solid fluid and beyond (8 oz): pedal still moves to near floor. 3) disconnected line to right front and re-installed blank plug to see if I still get a firm pedal on the left front; left front still has firm pedal. 4) removed blank plug, re-connected line to right front, removed hose at right front, replaced with NEW hose, tightened all connections, bled right front to solid fluid and beyond (12 oz), no leaks;pedal still moves to near floor.

Is there anything in the wheel cylinder that could be "absorbing" pressure? I'm running out ideas.

Steve

[John S.]

Re: 2nd Chapter_63 brake bleeding challenge

on my 74 i had problems due to my master cylinder not having a 1/16 inch of freeplay. in that car it had an adjustable rod that i set with no freeplay. randomly it would not allow the master cylinder to return all the way back and allowed air in the system.

[Joel T.]

Re: 2nd Chapter_63 brake bleeding challenge

Thanks for the responses. The line to the rear is still blanked off. Since last nite's post I have: 1) checked to make sure that brake shoes are being deployed against drum when pedal is pressed; yes they are, and there is no leak from the wheel cylinder. 2) with power bleeder, bled right front again to solid fluid and beyond (8 oz): pedal still moves to near floor. 3) disconnected line to right front and re-installed blank plug to see if I still get a firm pedal on the left front; left front still has firm pedal. 4) removed blank plug, re-connected line to right front, removed hose at right front, replaced with NEW hose, tightened all connections, bled right front to solid fluid and beyond (12 oz), no leaks;pedal still moves to near floor.

Is there anything in the wheel cylinder that could be "absorbing" pressure? I'm running out ideas.

Steve

Steve;

Honestly, I have no more specific answers for you...but maybe this will help... On my 1963, which sounds to be the same as yours; i.e. original MC and no power.. I had the same problem although I did not go to the lengths which you have gone to isolate the issue... I've done lots of drum brake jobs over the years and have never had so much trouble as I have had with my '63 (but I still love the car dearly!)

Someone mentioned the fact that you can adjust the length of the rod to the MC.. If you look under the dash you will see it and as I am told, if you adjust it you need to make sure to leave some amount of free play before contact with the MC plunger else your brakes will drag... I was too chicken to mess with the adjustment (yet) but it got me to thinking... prior to this I had tried the Mighty Vac method of pulling fluid out of each cylinder and got the same screwy results which you are referencing... firm pedal to no pedal for no apparent reason... drove me nuts and also drove my friend who is a long term Vette and general car guy (i.e. 1957 FI Duntov car) nuts as well. The way I finally got the pedal up was to use the old fashioned "pump the pedal" method but made absolutely sure that each pump went all the way to the floor... half stroke pumps did nothing! This leads me to believe that rod to the MC has something to do with the issue. Once I got a firm pedal, I was fine... and the system has worked fine since... the pedal could be a bit higher but again I suspect the rod needs adjusting...

My car still has some other brake issues which I need to address... for instance, in spite of replacing all hoses and cylinders, and having the MC relined, and flushing out the lines and blowing air through them to clear and dry them, I cannot get clear fluid through the system... what comes out of the cylinders is like swamp water.. and is a different color than what went in at the top! Really wierd!

Good luck, and keep us '63 guys posted!!!

Joel

[Harry S.]

Re: 2nd Chapter_63 brake bleeding challenge

Steve, let me summarize to see if I understand.

1) The rear brakes are disconnected from the system. I assume you disconnected them at the front brass block?

2) When you disconnect the right front from the system (meaning only the left front is active) the pedal is high and firm.

3) When you disconnect the left front from the system (meaning only the right front is active) the pedal goes to the floor.

If (3) is in fact true, best I can tell there are only three components that can be in the failure loop. I'll assume the brass block is OK.

I'll also assume there are NO leaks.

a) the wheel cylinder
b) the rubber brake line
c) the cross-over line

Since you replaced the rubber brake line, your left with a and b from above.

Again, if there are NO leaks, I'd attack the wheel cylinder next.

Except, look at the wheel cylinder and see if the pins are actually in the slots on the brake shoes! Check the shoe, spring, adjuster installation also. Also, adjust the shoes until they just touch the drum.

Pull the drum and post a picture.

[Harry S.]

Re: 2nd Chapter_63 brake bleeding challenge

Steve, I finished my fronts last week.

[Kenneth S.]

Re: 2nd Chapter_63 brake bleeding challenge

Here is a picture of my '63 right front brake. Note the self adjusting lever is above the adjusting wheel where yours is below. I can't see in your picture, but do you have the little spring that holds the adjusting lever up?
Ken

[Stuart F.]

Re: 2nd Chapter_63 brake bleeding challenge

Very interesting threads(s). I too replaced my brakes and MC last year, only I went from the sintered metallic to metrix ceramic linings. I also use a sleeved (rebuilt) 63 MC to replace the old generic 64 I had. I got very confused with mine due to new (incorrect) drums. When I finally cut my old drums to fit I finally got a reasonably good pedal, but still mushy. I bled them several times, and a local brake shop power bled them as well. It was acceptable, so I proceeded to run them in. Over time they have gotten better both with pedal firmness and stopping power.

When I replaced them, on my last drive into the garage, my pedal went to the floor. Over time, my system had taken on a lot of water and it mostly affected the right front cylinder.

I now use DOT 4 and it seems fine.

Stu Fox

[Harry S.]

Re: 2nd Chapter_63 brake bleeding challenge

Ken, yes, in that picture the spring was not installed yet. I knew it was missing when I took the picture. The lever went to the correct position above the star wheel after I put the spring in.

[Timothy B.]

Re: 2nd Chapter_63 brake bleeding challenge

Steve,

Someone may have mentioned this but make sure that right front brake is adjusted properly up to the drum so you can just fell resistance when turning with the tire on.

If there are no leaks that may be the reason the pedal goes down, it's filling the brake cylinder because it has to push far out.

[Harry S.]

Re: 2nd Chapter_63 brake bleeding challenge

Steve must be away today as he has not replied. Looking at all the suggestions, his fix is in here somewhere!