pop in the brake peddle when depressed Master cylinder?

Posted by Vintage41 On 2012/11/6 17:37:31

Guys I need a little help,

I have a 1941 Packard 120 I drive just about every day great fun. I was going through my normal fluid/suspension bolt/leak check and noted a small leak at the brake pressure switch so I replaced the switch and bled the brakes. After which I noted on the test drive you can depress the peddle only to feel resistance (as normal) but a slight pop in the peddle then it goes down another 10%. check all suspension seems tight appear to be coming from the driverside left lower area which is either a master cylinder or the drum brake on that side. The car doesn't pull to either side when this happens just a slight pop then peddle travels 10% further I'm thinking it's a master cylinder but wanted opinions?

4 wheel drum stock brakes

checked peddle linkage through the movement ok...
check suspension ok
bleed brakes 3 different times thinking air got into the lines
peddle feels firm car stops well

thanks for replies.