Slow Returning Brake Pedal Driving me nuts.

[moparspares]

I have had this ongoing problem with my slow returning Brake pedal and locking up if I hit pedal to hard on my 73 Duster. I have thrown money at the problem after suggestions from many.

Had the Booster redbuilt
Swapped out the Original prop valve to an adjustable Willwood.
Recod master Cylinder from Rock Auto (couple years old now)
New hard lines
New Flexible Rubber Lines

The only thing I havent replaced is calipers and master cylinder. Should I go the whole hog and replace these as well. This is driving me crazy. Any help appreciated.

 

[Syleng1]

Go to each wheel and have some one step on pedal and one by one open that particular bleeder screw. If the pedal releases faster then you know what corner it is an issue.
Do only one wheel per pedal press. Checking fluid level along the way so you don’t run out of brake fluid.
If that does not show a faster pedal then you know it’s in the proportion valve or the master / booster. Do the same with the master two lines (one at a time) to verify it is not the issue. Cracking lines one at a time after the pedal is pressed will give alot of info.

 

[67Dart273]

None of the rest of the system should have anything to do with the master returning. I would say this is all right in the area of the linkage, binding, etc, the master, sticking or other defect, or something wrong in the booster.

Not sure I'm about to explain this well, but there is no possible way, that the tiny 3/16 tubing and long runs in such as my big 'ol 2500 long bed big cab Cummins can return as fast as the master, AND that restriction is sorta why you can "pump up" the pedal if there's a little too much movement, AKA the rear drums out of adjustment or whatever. When you stab the master, you should be able to almost immediately give it another pump

This could even be as simple as one of the master piston springs broken, etc

 

[Inertia]

I had the special shouldered bolt that goes thru the pedal to the master cylinder pushrod bind, and cause similar to your issue.
Try loosening that bolt a half turn, and see if it frees up the pedal.
Repair as nec .
Good luck .

 

[72Duster440]

I had the special shouldered bolt that goes thru the pedal to the master cylinder pushrod bind, and cause similar to your issue.
Try loosening that bolt a half turn, and see if it frees up the pedal.
Repair as nec .
Good luck .

I had the same issue.

 

[Ricks70Duster340]

I have had this ongoing problem with my slow returning Brake pedal and locking up if I hit pedal to hard on my 73 Duster. I have thrown money at the problem after suggestions from many.

Had the Booster redbuilt
Swapped out the Original prop valve to an adjustable Willwood.
Recod master Cylinder from Rock Auto (couple years old now)
New hard lines
New Flexible Rubber Lines

The only thing I havent replaced is calipers and master cylinder. Should I go the whole hog and replace these as well. This is driving me crazy. Any help appreciated.

Another thing to check is where the master cylinder rod attaches to the brake pedal. There is a bushing that can get fouled up. I've had my pedal start squeaking so I took it apart and put some grease in there and all was good. Could be there is some binding going on there in yours.

 

[moparspares]

Thanks guys I am going to check the pedal assembly under dash as suggested. I dont think my backs gonna like it but Oh well!

 

[Muswagon]

My pedal not returning was a binding issue. Unbolt the master from the booster, and see how it goes. Should still return with the booster spring. If it does well with no binding, I would say the return spring in your master is toast. In the absence of binding, as others have wrote, there is nothing else preventing return other than spring issues in the master and or booster