1957 Tbird Brake Pedal Free Travel

[Clif57]

My 57 Tbird has much too much brake pedal free travel . I have the shop manual and on page 288, brake pedal adjustment, it says,”Loosen the lock nut on the eccentric bolt, then rotate the bolt until the free travel is within 5/16-7/16 inch.” I have about 3” of pedal free travel. Can I make up that amount (3”) of free pedal travel? Also, there’s not much room under there, any suggestions on how to make my task easier?

 

[jack-in-sac]

My 57 Tbird has much too much brake pedal free travel . I have the shop manual and on page 288, brake pedal adjustment, it says,”Loosen the lock nut on the eccentric bolt, then rotate the bolt until the free travel is within 5/16-7/16 inch.” I have about 3” of pedal free travel. Can I make up that amount (3”) of free pedal travel? Also, there’s not much room under there, any suggestions on how to make my task easier?

When working under the dash it is often best to remove the seat for more comfortable access, good luck.

 

[Cuul59]

My 57 Tbird has much too much brake pedal free travel . I have the shop manual and on page 288, brake pedal adjustment, it says,”Loosen the lock nut on the eccentric bolt, then rotate the bolt until the free travel is within 5/16-7/16 inch.” I have about 3” of pedal free travel. Can I make up that amount (3”) of free pedal travel? Also, there’s not much room under there, any suggestions on how to make my task easier?

Hi Cliff(?), It sounds like you may have a problem with either air in the system or brakes that are in need of adjustment. If you pump the pedal a few times quickly, does it get higher with each pump? If so, you should start by bleeding the brakes. A good time to change the fluid too if it’s been a while. If the pumping action doesn’t change the pedal height, try adjusting the brakes. Use an adjusting tool inserted in the backing plate slot for each wheel. I like to adjust until there is a slight drag...giving the wheel a quick spin and release it should stop after about 2 full rotations or less. If your pedal is still low after that, you can try to adjust the eccentric. Beyond these three steps, you could have a bad master. Good hunting!
Neil

 

[Boron]

I am not sure about maximum adjustment of free travel although I am tackling that issue now after installing the mechanism for the Casco mechanical switch. I am in my 70s and removing seats is not such a simple task for me without help. However, I find that I can slide under the dash from the side if I support my back. Not the prettiest system but I put a couple of foam cushions on top of a cooler. Works for me.

 

[Ward 57]

If I remember correctly the Thunderbird did not have an adjustable throw on the pedal due to it's design. The other cars DID have an adjustable pedal where the booster was attached to the M/C.

 

[doug7740]

There should be 5/16" to 7/16" free travel at the brake pedal. The free travel is adjusted by turning the eccrentic bolt at the brake pedal.

doug7740
1955 Thunderbird Blue

 

[74 Harley]

It sounds to me like you need to adjust all four brakes first. Then check for solid pedal. Bleeding would be the second try, eccentric bolt is the last after every thing else is correct.

 

[doug7740]

The 5/16" - 7/16" free travel is the amount of travel before the master cylinder push rod contacts the master cylinder. This free travel is needed to ensure that there is no brake pressure after your foot is off of the pedal.

If there is a low brake pedal the brakes should be inspected first and then adjusted and bled if needed.

doug7740
1955 Thunderbird Blue

 

[paul5456]

The 5/16" - 7/16" free travel is the amount of travel before the master cylinder push rod contacts the master cylinder. This free travel is needed to ensure that there is no brake pressure after your foot is off of the pedal.

If there is a low brake pedal the brakes should be inspected first and then adjusted and bled if needed.

doug7740
1955 Thunderbird Blue

I disagree with that and the picture shows the 5/16 to 7/16 at the pedal. The gap between the rod end and the master cylinder should be around 1/8 to 3/16 from what I have heard.

 

[paul5456]

My 57 Tbird has much too much brake pedal free travel . I have the shop manual and on page 288, brake pedal adjustment, it says,”Loosen the lock nut on the eccentric bolt, then rotate the bolt until the free travel is within 5/16-7/16 inch.” I have about 3” of pedal free travel. Can I make up that amount (3”) of free pedal travel? Also, there’s not much room under there, any suggestions on how to make my task easier?

Power brakes or non-power. If power, are you checking it with the engine on?

 

[doug7740]

I disagree with that and the picture shows the 5/16 to 7/16 at the pedal. The gap between the rod end and the master cylinder should be around 1/8 to 3/16 from what I have heard.

I don't know for sure, but it might be that 5/16" to 7/16" at the pedal equates to 1/8" to 3/16" between the rod end and the master cylinder, How would you measure the gap between the rod end and the master cylinder otherwise.

doug7740
1955 Thunderbird Blue

 

[Ward 57]

I don't know for sure, but it might be that 5/16" to 7/16" at the pedal equates to 1/8" to 3/16" between the rod end and the master cylinder, How would you measure the gap between the rod end and the master cylinder otherwise.

doug7740
1955 Thunderbird Blue

Just checked the shop manual and the 5/16" to 7/16" is correct. The piston in the M/C has a spring to retract it after application so no adjustments needed there.

 

[74 Harley]

Keep in mind that the measurements at the rod end will be different at the pedal because it travels on am arc , ward and Doug are both correct just from opposite ends.