brake pedal movement

Discuss all things Model T related.
Forum rules
If you need help logging in, or have question about how something works, use the Support forum located here Support Forum
Complete set of Forum Rules Forum Rules

Topic author
Rod Petrie
Posts: 85
Joined: Sun Jun 16, 2019 10:44 am
First Name: Rod
Last Name: Petrie
* REQUIRED* Type and Year of Model Ts owned: 1926 TT
Location: Thedford, Ne

brake pedal movement

Post by Rod Petrie » Fri Sep 27, 2019 8:52 am

As I am disassembling my 26TT I am trying to understand how everything works, I disconnected the transmission band so I could remove the brake pedal. I want to weld a tab on the bottom to operate the auxillary outside brakes. The brake pedal does not move very far when pressed which I see is normal. I can't understand how this small amount of movement will be enough to transfer clear back to the brakes to compress them. Do I need to do something different?

User avatar

DanTreace
Posts: 3296
Joined: Sun Jan 06, 2019 10:56 am
First Name: Dan
Last Name: Treace
* REQUIRED* Type and Year of Model Ts owned: '23 cutoff, '25 touring, '27 touring
Location: North Central FL
MTFCA Number: 4838
MTFCI Number: 115
Board Member Since: 2000
Contact:

Re: brake pedal movement

Post by DanTreace » Fri Sep 27, 2019 9:50 am

Ron

As long as you weld the tab on the brake pedal in lower correct spot the external brake shoes only need a small amount of pedal movement. Take advantage too if the rearmost position of the pedal cam, I use a large spring to keep the pedal rearward.

Then the first bit of travel operates the exterior rear shoes. And more pedal push begins closing the transmission brake band.

In these photos the rods to the exterior brakes aren’t mounted. And the pedal travel from zero, fully back in the cam, allows for 3” of pedal push until the trans band starts to close on the drum. More push locks the trans brake, so have that trans brake fitted a tad loose for this reason.

Photos are full size...iphone, so ‘click’ on the images and they will go right side up! Forum Thing on photos sometimes :roll:
3482173F-27CD-4129-97A6-905CD00346B0.jpeg
3C115307-C67C-4319-BDA9-C5EB27D7FFFE.jpeg
The best way is always the simplest. The attics of the world are cluttered up with complicated failures. Henry Ford
Don’t find fault, find a remedy; anybody can complain. Henry Ford


Mustang1964s
Posts: 254
Joined: Sun Jan 06, 2019 10:48 pm
First Name: Steve
Last Name: Bourgeois
* REQUIRED* Type and Year of Model Ts owned: 1914, 1926
Location: Waco, TX
MTFCA Number: 29784
MTFCI Number: 22970
Board Member Since: 2007

Re: brake pedal movement

Post by Mustang1964s » Fri Sep 27, 2019 9:53 am

Pulling the hand brake move the foot break just a little bit.
This put engages the clutch and the truck is in neutral.
The hand brake engages the rear brakes at the wheels.
The foot brake engages the transmission brake.

Hope this makes it clear as mud.

User avatar

Mark Gregush
Posts: 4956
Joined: Sat Jan 05, 2019 1:57 pm
First Name: Mark
Last Name: Gregush
* REQUIRED* Type and Year of Model Ts owned: 1925 cutdown PU, 1920 Dodge touring, 1948 F2 Ford flat head 6 pickup 3 speed
Location: Portland Or
MTFCA Number: 52564
Board Member Since: 1999

Re: brake pedal movement

Post by Mark Gregush » Fri Sep 27, 2019 12:32 pm

Without knowing WHAT setup he is using...with the Ez-Slide installed moving the parking brake lever should not move the brake pedal. I made my own equalizer that hangs under the parking brake cross shaft so applying the parking brake does not affect the brake pedal.
As suggested, back the tension off the transmission brake to get more swing, but keep some so it still will work.
Before you go gung-ho do some driving test. With everything hooked up, set the bands so they are cool or just warm to the touch after a drive, not dragging too much. Then do a braking test, you may not need as much pedal moment as you might think.
I know the voices aren't real but damn they have some good ideas! :shock:

1925 Cut down pickup
1920 Dodge touring
1948 Ford F2 pickup


Topic author
Rod Petrie
Posts: 85
Joined: Sun Jun 16, 2019 10:44 am
First Name: Rod
Last Name: Petrie
* REQUIRED* Type and Year of Model Ts owned: 1926 TT
Location: Thedford, Ne

Re: brake pedal movement

Post by Rod Petrie » Sat Sep 28, 2019 8:45 am

By loosening the transmission band will that allow the pedal to extend further out of the transmission? If so, then the pedal can be pressed further down.


HPetrino
Posts: 490
Joined: Sun Jan 06, 2019 11:14 am
First Name: Henry
Last Name: Petrino
* REQUIRED* Type and Year of Model Ts owned: 1918 TT
Location: Modesto, CA

Re: brake pedal movement

Post by HPetrino » Sat Sep 28, 2019 10:29 am

You can increase the travel of the point of connection by lengthening the tab. The longer it is the more distance it will move with the same amount of pedal movement.

Having said that, I'm going to offer a little free advice. There are some of us, including me, who believe it's a mistake to have the brake pedal operate both the transmission brake and auxiliary brakes. We believe when auxiliary brakes are installed and made to operate properly the transmission brake should be abandoned altogether. Some automotive engineers in the day seemed to agree with this opinion due to the fact that some of the auxiliary brake kits came with a replacement brake pedal that was absent the cam necessary to operate the transmission brake, making it impossible to operate both.

Anyhow, my $0.02 worth.


Scott_Conger
Posts: 6428
Joined: Sun Jan 06, 2019 11:18 am
First Name: Scott
Last Name: Conger
* REQUIRED* Type and Year of Model Ts owned: '13, '15, '19, '23
Location: Clark, WY
Board Member Since: 2005

Re: brake pedal movement

Post by Scott_Conger » Sat Sep 28, 2019 10:40 am

And adherants to that plan, when stoped on a hill, with modern Rocky brakes, can rely on the guy behind them to keep from careening to the bottom of the hill

My dad had rockies put on his depot hack by such a person. The first time I backed it out of his garage, the gentle slope into the 90 degree angle drive (and the ditch behind) was too much for the Rockies and off I went...I managed to get stopped just in time by stomping ALL pedals and stalling. It is NOT a steep slope.

Back into the garage and I found the brake band totally slack...reajusted to grab if brake pedal set upon HARD. Presto. Brakes in reverse. What a concept.

Not my plan, but if it works for you, go for it...just make sure the guy behind you is a very good friend and needs a new radiator.
Scott Conger

Tyranny under the guise of law is still Tyranny

NH Full Flow Float Valves
Obsolete carburetor parts manufactured


HPetrino
Posts: 490
Joined: Sun Jan 06, 2019 11:14 am
First Name: Henry
Last Name: Petrino
* REQUIRED* Type and Year of Model Ts owned: 1918 TT
Location: Modesto, CA

Re: brake pedal movement

Post by HPetrino » Sat Sep 28, 2019 11:04 am

It all depends on the auxiliary brakes you have. What you say is true regarding repop Rockies which, unlike the original Rockies, have the band anchored at its end. I use a set of Bennetts, which have the bands anchored at the center. With them I get equal braking when moving forward or backward. I don't even keep a transmission brake band in the transmission.

If I remember the photos posted in an earlier thread by Rod, his auxiliary brake bands are anchored at the center.


25 roadster john
Posts: 50
Joined: Sun Jan 06, 2019 3:17 pm
First Name: John
Last Name: Pawlowski
* REQUIRED* Type and Year of Model Ts owned: 1925 Roadster
Location: Milton Delaware
MTFCA Number: 49635

Re: brake pedal movement

Post by 25 roadster john » Sat Sep 28, 2019 11:43 am

Since the transmission brake drum is attached to the engine you really can't keep pressure on the brake pedal with engine running correct? I've been told short applications only. I'm in the process of installing an AC brake system purchased from Larry Skidmore and Rich Baughman . Bill Ramsey is a big help with the installation. Look for a thread from 2016, Small drum AC brakes. Bill goes into detail with his experiences with his installation, plenty of photos too.They are great to deal with and helpful. Was supposed to install last year but you know how that goes. But I'm looking to have the AC brakes apply before the transmission brake also.


Scott_Conger
Posts: 6428
Joined: Sun Jan 06, 2019 11:18 am
First Name: Scott
Last Name: Conger
* REQUIRED* Type and Year of Model Ts owned: '13, '15, '19, '23
Location: Clark, WY
Board Member Since: 2005

Re: brake pedal movement

Post by Scott_Conger » Sat Sep 28, 2019 1:14 pm

John

the brake drum is solidly affixed (effectively) to the drive shaft. If the engine is in neutral, the engine is decoupled from the rear end, and the brake can be applied any amount you want (or dare) to bring the car to a halt and to hold it in place. The admonition to pump the brake has nothing to do with engine...it is about allowing oil to carry heat away from the drum and not overheat it with braking friction.
Scott Conger

Tyranny under the guise of law is still Tyranny

NH Full Flow Float Valves
Obsolete carburetor parts manufactured

Post Reply Previous topicNext topic