Brake Pedal Return Spring 66 Newport

[Chris1966Newport]

Hi Everyone,

i just bought this Newport a few weeks ago and just did a full brake job. In the process i noticed that someone put a spring on the bake pedal to pull it into the return/top position (to turn off the brake lights???). Any Ideas what could be worn or wrong for this to happen in the first place?

Thanks,
Chris

 

[Ross Wooldridge]

Brake pedal light switch misadjusted and they didn't know how to adjust.
Brake master cylinder or booster pushrod sticking. Likely the master.
Broken return springs inside master and or booster.
Wheel cylinders sticking.
Brake shoes hanging up.

All of the above shows me that the previous owner (or their mechanic) didn't have a frickn clue...

 

[Chris1966Newport]

Thanks for the insight, the master and all wheel cylinders were replaced last week so that alone might fix the issue. The rear wheel cylinders i took off were rusted closed, so maybe that is why there was not enough return pressure.

I upgraded to a Dual Master cylinder(ordered a 67 newport with manual drums), and used the brake rod from the single that was on the car. Any chance this is causing extra play in the pedal? from what i recall when i did the research, the push rod did not need to be switched.

Thanks for the help,
Chris

 

[Ross Wooldridge]

As long as the rods are the same length it shouldn't be an issue.

 

[BillGrissom]

Correct. The only spring needed is the one inside the MC which pushes the piston back. Yes, the same brake rod. But, most manual MC's I have seen come w/ the pushrod (view photos in rockauto). The brake rod length just determines where the pedal winds up.

The switch is adjustable and should just sense the pedal, not stop its motion. I also put a dual MC in my 65 Newport, but used a later aluminum one (for 99 Breeze w/ ABS) on a 2-4 bolt adapter plate. Sounds like your Newport has manual brakes. When my booster leaked, it took 2 feet on the pedal to stop it, and still rolled thru a stop sign, but a manual MC has a smaller bore (for less effort). A manual MC needs a rubber bushing on its grooved tip. The bushing locks into the MC piston ID. You can buy several places (Dr. Diff?). A manual MC also has metal plate on the rubber dust bellows which prevents the piston from coming out of the bore. I use DOT 5 silicone in most of my cars so no more rusty brake innards.

 

[Chris1966Newport]

A manual MC needs a rubber bushing on its grooved tip. The bushing locks into the MC piston ID. You can buy several places (Dr. Diff?)

Can you explain this a little better?

 

[Davea Lux]

Thanks for the insight, the master and all wheel cylinders were replaced last week so that alone might fix the issue. The rear wheel cylinders i took off were rusted closed, so maybe that is why there was not enough return pressure.

I upgraded to a Dual Master cylinder(ordered a 67 newport with manual drums), and used the brake rod from the single that was on the car. Any chance this is causing extra play in the pedal? from what i recall when i did the research, the push rod did not need to be switched.

Thanks for the help,
Chris

Is this a power or manual brake system?

Dave

 

[Chris1966Newport]

Manual Brakes.

 

[traintech55]

Can you explain this a little better?

The rubber bushing installs on the brake rod and holds the rod into the master cylinder. The absolute last thing you want to have happen is the rod pop out of the master cylinder piston.

 

[Chris1966Newport]

The rubber bushing installs on the brake rod and holds the rod into the master cylinder. The absolute last thing you want to have happen is the rod pop out of the master cylinder piston.

Are you referencing the single pot master cylinder? This style I agree the rod could fall out. A dual master cylinder, which I installed, I don't think the design would allow the rod to fall out unless it was way too short (like a inch short).

I don't recall installing a bushing so I'm just trying to make sure I didn't miss anything.

Thanks for all the help.

Chris

 

[Chris1966Newport]

i know this is not exact, but i don't see how a bushing would keep the brake rod from falling out?

 

[traintech55]

i know this is not exact, but i don't see how a bushing would keep the brake rod from falling out?

View attachment 153426

ALL manual master cylinders have a groove machined into the piston so the bushing can retain the push rod into it. It is not on a master cylinder for a car with power brakes. This is the EXACT reason Chrysler did this on all their cars. If yours does not have the groove, it is the wrong master cylinder.

 

[Ross Wooldridge]

Just a note re the above post, a power brake master will not have the right bore and may be too weak.

 

[Davea Lux]

Thanks for the insight, the master and all wheel cylinders were replaced last week so that alone might fix the issue. The rear wheel cylinders i took off were rusted closed, so maybe that is why there was not enough return pressure.

I upgraded to a Dual Master cylinder(ordered a 67 newport with manual drums), and used the brake rod from the single that was on the car. Any chance this is causing extra play in the pedal? from what i recall when i did the research, the push rod did not need to be switched.

Thanks for the help,
Chris

If your wheel cylinders were corroded to the point that they were stuck shut, now would be a very good time to replace all of the rubber brake hoses as you may have had a moisture intrusion problem into the brake system. Moisture combines with brake fluid to form corrosive by-products that rust metal parts and degrade rubber parts. The brake rod should work with either master cylinder and the return spring is not necessary and should be removed.

Dave

 

[Davea Lux]

i know this is not exact, but i don't see how a bushing would keep the brake rod from falling out?

View attachment 153426

The rubber boot performs that function on the master shown, as long as rod is the correct length and the pedal stop that limits the upward travel of the pedal is in place, the rod should not be able to disengage the master cylinder.

Dave

 

[Chris1966Newport]

The rubber boot performs that function on the master shown, as long as rod is the correct length and the pedal stop that limits the upward travel of the pedal is in place, the rod should not be able to disengage the master cylinder.

Dave

Thanks Dave, I did replace all 3 of the flex lines as well as all of the hard lines.

I think I just need to adjust the pedal stop like you said. The top of the pedal has about a inch of travel in it before it makes contact with the rod.

The car stops pretty well now, but the pedal feels a little low and soft to me. I actually took it to my mechanic to give it a once over. They said they got a little more air out of the lines and adjusted the brakes a little better, otherwise they said the pedal felt good to them for a manual drum car. sound ok to you?

Thanks for everyone's help!
Chris

 

[Davea Lux]

Thanks Dave, I did replace all 3 of the flex lines as well as all of the hard lines.

I think I just need to adjust the pedal stop like you said. The top of the pedal has about a inch of travel in it before it makes contact with the rod.

The car stops pretty well now, but the pedal feels a little low and soft to me. I actually took it to my mechanic to give it a once over. They said they got a little more air out of the lines and adjusted the brakes a little better, otherwise they said the pedal felt good to them for a manual drum car. sound ok to you?

Thanks for everyone's help!
Chris

You should have 3/4" to 1" free play overall before you start to feel the brakes engage. As long as you are happy with the way the car stops, it should be good. A manual system will always have a different feel than a power assisted one. You can adjust the pedal stop to your comfort level so long as you maintain enough free play to keep the brakes from dragging. I would suggest keeping at least 1/2" rod clearance to start, that should make a big difference in the pedal height and where the brakes start to engage. Drive the car and monitor the fluid level in the master to be sure that you do not have any leaks.

Dave