Brake Pedal Return

-
T

Two Lane

Well-Known Member
Joined
Apr 13, 2007
Messages
61
Reaction score
1
('71 Duster/Auto/Slant-Six/All Factory-Stock/25K)

I had to do an emergency 4-wheel lock-up panic stop,
from 70mph to narrowly avoid hitting a deer. I actually heard
a sound like something cracking from the underdash area
of the brake pedal assembly when I literally stood on the brakes.

Since then, the brake pedal does not fully return to
its top-most position, and leaves the brake lights on.

It does not engage the brakes, just the lights.

You must place the top of your shoe underneath
the back of the pedal after each use to manually
push the pedal back up, in order to get the
brake lights off.

What parts do I need to correct this?

(My local MOPAR parts counter staff
just go "duhhhhhhhhhh" when I've
tried to order any thing for the Duster
without a part number to give them.)

Thanks for your expertise & help on this!
 
You'll have to determine where the problem is first. I've seen rusted/weakened firwalls allow the master cylinder or booster to push away.
 
Thanks for the reply, RF, very appreciated!!

Looks like I'll
have to take the car
to an "old-school" mechanic
(very rare around here)
and have them inspect
the various possibilities
as to causation & cure.

Due to a back wound,
I can't crawl around
the suspect areas myself,
especially underdash areas.

(Guess I was hoping to hear
"you've cracked a brake lamp
actuator, part# blah-blah-blah".)

Keeps you busy with the
footwork needed to keep
the brake lights off, so
I'll park it until I find a shop
or mechanic to trust it with.

Thanks again!
 
I agree with the above you prolly bent somethin. Only other issue could be like a restricted brake line or something thats not allowing the fluid to return. But that wouldnt quite make the cracking sound you heard.
 
I think your booster is **** ... I had the same issue w/ the pedal not returning w/o help from my toe .. Today I took off the master cylinder and the inside of the can had major chunks of rust and crap inside it ....I would bet $$$ that something let go inside of your booster

Kenny
 
Thanks for each helpful reply!

Have an appointment for
the Duster Friday the 9th.

I will post back
whatever the problem & cure
turns out to be.

Thanks guys!----Happy November!!
 
O.K., A-Body buds...

Here's the update on my brake pedal nightmare.

Took the car in for its appt. on the 9th.

The shop owner (Brakes & Alignment-only shop)
and his son spent over an hour on the car all together.

Ruled out any problem with the master cylinder, and/or its components.

(They had replaced the original MC w/a NAPA-Gold unit only 6 months ago, due to a leak. Vehicle only has 25K & has led an incredibly sheltered life.)

They said they didn't want to get the underdash brake pedal components dissassembled on a Friday afternoon w/o spare/replacement parts on hand, if needed. That was very understandable!

They seem to think a "return spring" (like the spring on a clothespin)
is broken, but could not locate an exploded-view diagram of the
underdash brake pedal assembly in any of their considerable references.

So, before making a follow-up appointment, I'll need to take them
the exploded-view illustration and have a source or supply of any
likely needed repair/replacement components.


**Can you guide me on how to locate such a pic, & a parts supplier?**

The car is parked until repaired, so your help is greatly appreciated!
 
like ted said, there is no return spring. the spring inside the master that the piston pushes on is the only "return" spring so to speak. they need to check the firewall mounting area and the bracing that the pedal pivots in under the dash.
 
This is an issue for my Barracuda. I haven't had time to get to the root of the problem. The brakes work fine but the pedal doesn't come up, leaving the lights on. So uh..I temporary assessed the situation with a carb spring that attaches to the pedal and stretches up under the dash...just until the carshow season is over and its parked long enough for me to work on it.
 
Thanks for each & every reply!!

Have printed this thread,
and given it to the fellows
who will be checking it out
on the 4th of December.

I'll keep you updated,
and please keep me
apprised of any extra
thoughts you may have.

Much appreciated!
 
Just to clarify, the Duster has
factory-stock manual drum brakes,
with a new NAPA-Gold master cylinder.

Thanks again!
 
Two Lane said:
Thanks for each & every reply!!

Have printed this thread,
and given it to the fellows
who will be checking it out
on the 4th of December.

I'll keep you updated,
and please keep me
apprised of any extra
thoughts you may have.

Much appreciated!
Click to expand...

Have also found a pair of factory
Mopar 1971 Plymouth service manuals
to take along also.

Wish these were available
page-by-page on the internet
as online references.
 
I would pull the master cylinder and check the brake rod to see if it bent and check the end that connects to the pedal for a shattered nylon grommet. i believe there is a plastic sleeve that keeps the rod from binding in the m/c. any of these things could give you the slack causing the problem.
 
All you need to do is adjust your brake light switch on the brake pedal! My pedal did the same thing, had to pull the pedal back with my foot to get the brake lights off. I couldn't figure it out, my buddy looked at it, he just bent the switch a little, presto! Problem fixed, Pedal is fine, lights go off!! Unless your switch is broken then this will also cause your lights to come on or not work at all. Then buy a new one, easy install.
 
You must log in or register to reply here.
-

Back
Top