The Ford Barn

GeneBob · 04-12-2023, 10:41 PM

Maybe a nit-pick but several posters mentioned "self actuating" brakes. That would be very scary. When the brake shoes help to add to the braking power it is "self energizing". The "leading" brake shoe rotates to add pressure to the "trailing" shoe through the adjuster when the flathead Ted's kit is installed. This makes the mechanical brakes act more like modern drum brakes.
On more modern drum brakes the transfer of added load to the trailing shoe happens through the adjuster or self adjuster when present.
Self actuating brakes would make life more exciting!
BTW, the added power of the self energizing portion of the braking can be 15%. That is a big help.

updraught · 04-13-2023, 02:44 AM

"Self-Actuating Mechanism:
Drum brakes are also known as self-actuating brakes. As the brake pads wears out, they have to travel a greater distance to press against the wheel drum. Therefore, self adjusting mechanism is used to automatically re-position the resting point of the hinges on which the brake pads are hinged, so as to get them closer to the drum.

Advantage of using a drum brake:

There is only one major advantage of drum brakes, it is cheap."

http://howcarpartswork.blogspot.com/...ng-brakes.html

GeneBob · 04-13-2023, 07:28 PM

updraught,
Whoever wrote that article does not know much about drum brakes.
The mechanism they refer to is "self adjusting" not "self actuating". The adjuster or self adjuster is between the ends of the shoes opposite the anchor point. The reference to a hinge point is confusing as it is not the anchor point that does the adjusting.
Anyway, the Model A brakes are improved with some ability to self energize.

04-12-2023, 10:41 PM	#41
GeneBob Senior Member Join Date: May 2017 Location: Denver Area Posts: 433	Re: Brake improvement for Model A's Maybe a nit-pick but several posters mentioned "self actuating" brakes. That would be very scary. When the brake shoes help to add to the braking power it is "self energizing". The "leading" brake shoe rotates to add pressure to the "trailing" shoe through the adjuster when the flathead Ted's kit is installed. This makes the mechanical brakes act more like modern drum brakes. On more modern drum brakes the transfer of added load to the trailing shoe happens through the adjuster or self adjuster when present. Self actuating brakes would make life more exciting! BTW, the added power of the self energizing portion of the braking can be 15%. That is a big help. Last edited by GeneBob; 04-13-2023 at 07:21 PM. Reason: Reworded for clarity of leading and trailing shoes, not front and back.

04-13-2023, 02:44 AM	#42
updraught Senior Member Join Date: Feb 2015 Location: Australia Posts: 1,971	Re: Brake improvement for Model A's "Self-Actuating Mechanism: Drum brakes are also known as self-actuating brakes. As the brake pads wears out, they have to travel a greater distance to press against the wheel drum. Therefore, self adjusting mechanism is used to automatically re-position the resting point of the hinges on which the brake pads are hinged, so as to get them closer to the drum. Advantage of using a drum brake: There is only one major advantage of drum brakes, it is cheap." http://howcarpartswork.blogspot.com/...ng-brakes.html

04-13-2023, 07:28 PM	#43
GeneBob Senior Member Join Date: May 2017 Location: Denver Area Posts: 433	Re: Brake improvement for Model A's updraught, Whoever wrote that article does not know much about drum brakes. The mechanism they refer to is "self adjusting" not "self actuating". The adjuster or self adjuster is between the ends of the shoes opposite the anchor point. The reference to a hinge point is confusing as it is not the anchor point that does the adjusting. Anyway, the Model A brakes are improved with some ability to self energize.