Front disk brakes not releasing.

[BPTracing]

I installed a new power disk brake setup from Right Stuff on my 67 Dart. Everything seemed to fit nicely and bled easily.

On the first drive I noted significant drag on the front. I did keep the original proportioning valve in the system.

The brakes release immediately when I cracked the line at the master cylinder.

Am I correct that if the pressure is held above the the proportioning valve, it is likely a master cylinder issue?

The rear drum brakes work properly.

 

[Dana67Dart]

Check the push rod depth into the master.

Too deep can cause this situation.

 

[RustyRatRod]

Check the push rod depth into the master.

Too deep can cause this situation.

THAT ^^^^^

 

[Dana67Dart]

Also check that the manual brake pushrod keeper little rubber thingy is not in the mc pushrod hole. (Iirc that is not needed on power brakes and can cause interference)

 

[CFD244]

Are you using a 4 wheel drum master? If so, there is a residual valve in the outlet that would feed the front brakes. This needs to be removed if you are installing disc brakes from a drum brake set-up.

 

[Kendog 170]

Yes post 5 but if it's a disc MC do you have the spacer between MC and Cowl panel. I had that issue until I added the spacer.
Excessive Front Brake Drag

 

[Dana67Dart]

if it's a disc MC do you have the spacer between MC and Cowl panel

new power disk brake setup from Right Stuff on my 67 Dart.

He installed a power brake setup

The pushrod from the booster to the MC is adjustable.

My money is on the piston is not being allowed to return fully due to incorrect push rod length.

 

[BPTracing]

Thanks for the insight everyone. I will loosen the master cylinder this evening and see if a little gap cures the issue. I recall the adjustable pin on the booster, and thought it was a little long when I did the install. So that is probably the issue and should be easy to correct.

Thx!

Scott

 

[Dana67Dart]

So that is probably the issue and should be easy to correct

Basically once there is no keeper in the piston hole..

Measure from the mounting surface of the master to the bottom of the home.

Then make the rod a tiny amount shorter from the tip of the push rod to the mounting face of the booster.

A tiny dab of grease on the end of the rod wouldn't hurt.

 

[BPTracing]

Problem solved. Brakes released when I unbolted the master cylinder. Shortened the rod, locktite the adjuster, reassembled. All good! Stops on a dime! Now I need to figure out why the backup camera lost video connection.

Thanks all for the input.

 

[Dana67Dart]

Now I need to figure out why the backup camera lost video connection

That's easy....

The real steel of the car is acting like a faraday cage and blocking the signal.

Add a flux capacitor and your problem is solved