VCCA Home Forums TECHNICAL - 1945 AND NEWER 1946-1948 Parking Brake Whistle

Anyone ever install one of these? I am installing one on my 1948 Chevrolet Fleetmaster Coupe. The plunger that moves out when you pull the emergency brake on is spring loaded out. It seems to me it should be spring loaded in. The spring on the plunger(inside the unit)is so strong it overcomes the vacuum. Has anyone had one of these apart or know anything about them or have one that works? The instructions show an external spring from the hand brake lever to the plunger on the whistle, but I don't see how that spring would push the plunger in when the brake is released. I have all the parts shown on the Instruction sheet and everything was in the original box. I think the whistle was assembled wrong and the internal spring should the plunger in not out. Anyone have any ideas or info?
Thank for any help,
j7l2

I had a bunch of them years ago. I thrw them out when I discovered they did not work due to old age.

What goes wrong with them with age? The only parts are a brass plunger a spring and the housing no seals or any other parts. Mine whistles all the time. I thought the vacuum would pull the plunger and that would shut off the whistle, but the spring behind the plunger is stronger than the vacuum. My vacuum is at 21 inches. I think the spring should be in front off the plunger to shut the vacuum off and when you pull the brake on it pulls the plunger off its seat. I would like to know if anyone hass ever had one that worked correctly. Thank you for your input.
Regards,
j7l2