1964 Parking Brake Doesn't Hold

[Hoopy]

I recently had my master cylinder changed out. Something changed with my parking brake as it no longer stays down when applied. It ratchets back up, doesn't hold - it never did that before. Initially I figured the vacuum line had come off the neutral safety switch (its new). It had. That line looked old, so I replaced it. Now reattached, the parking brake sticks slightly better, but it still isn't holding very long. It kicks back up, unable to stay down. I checked the vacuum canister and all the lines into it are secure. Any thoughts or recommendations?

 

[64ZCODE]

Hello Hoopy. Sounds like the parking brake mechanism beneath the foot pedal is gummed up or posibly worn out. The mechanism has a ratchet and a manual release lever that may be gummed up/stuck. Try dousing the mechanism with penetrating oil and working the parking brake pedal and the manual release lever and see if it frees up and will stay engaged when set. It should only release when it sees vacuum from the vacuum line, or when the manual release lever is depressed.

Doug

 

[BigClay]

Also, the brake release is controlled by the Neutral Safety Switch. The vacuum lines are connected to that switch. Possibly the vacuum lines have become disconnected and/or the switch has gone bad.