1962 Skylark Convertible Brakes Problem

[Skylark4367]

Some friends are helping me repair the brakes on my Skylark.  They replaced all the wheel cylinders and brake hoses, and adjusted the brakes.  The lines are in good condition.  I bought a rebuilt master cylinder from a major parts house.  They installed the master cylinder and added new fluid, and bled the system.  When testing the system, the brake pedal consistently went to the floor.  Pumping it didn't help.  There was a rebuild kit available in the garage so they rebuilt the old master cylinder.  Once that was installed, we got the same result.  We suspect the master cylinders are defective, but want to be sure we didn't miss anything.  Has anyone had an experience like this or is there something peculiar to these cars that we're missing.  Thanks in advance for any suggestions.

[JohnD1956]

Sounds like air in the lines still, or the brakes are not fully adjusted.  

[Frank DuVal]

Ditto. 

 

Two master cylinders doing the same thing, look elsewhere. Also, bench bleeding the master usually shows up issues with the master.

 

And, putting a plug in the output of the master really tells you if the master is at fault. What? Don't want to go to the store and try to find an elusive inverted flare blank? Just take the old steel line (you said there are new ones ) and cut several inches from the old master cylinder fitting, fold the end over once or twice to seal it (you can solder or braze if you like, this is not for driving down the road, just testing) , screw it in and see if th emaster holds pressure.

[jsmittie41]

I'd suggest checking all  of the wheel cylinders to make sure one of them didn't blow out.  If the brakes weren't adjusted properly a piston may have blown out of the cylinder.  If the wheels are on you'll find brakes fluid running out of the bottom of the brake drum.

A suggestion I'd offer for your 62 is to replace the adjusting hardware with 1963 Special/Skylark hardware.  63 was the first year for automatic self-adjusting brakes.  I did that on mine.  everything was a direct fit    

[Brooklyn Beer]

Tried a vacuum pump on each cylinder?  Since I am always working by myself it is a great thing for doing brakes.

[Skylark4367]

The new master cylinder had a bad thread in the flare for the brake line.  The brake line wouldn't seat correctly.  When it was bench tested it leaked.  They installed a rebuild kit in the old master cylinder and finally got some pressure.

[Skylark4367]

We sent the master cylinder back to the vendor; they agreed that it was defective and issued a refund.  The original master cylinder is being re-sleeved.