MAKING MODEL TT TRUCK PARKING EMERGENCY BRAKES to SERVICE BRAKES
Posted: Sat Dec 05, 2020 8:21 pm
Since posting pictures of my Model TT Farm Truck project, viewtopic.php?f=2&t=17453
I have had several people ask/email me about making my parking/emergency brakes into service brakes instead of using rear outside band brakes. First it was not my idea, I heard a rumor about another person doing it on his TT truck, but did not know how he did it. Also, I think I read that you can do it on the 26/27 Model T. I did this because on the Model TT truck, you have big brake drums with four lined brake shoes, so it should work just fine if the drums and brake shoe linings are good. The parts I used for this project was: a brake equalizer kit (bought this off an individual, I think venders have this too)(the tang they send, that is to be welded to the bottom of the brake pedal, will be too short, you will need to make a longer one because the TT frame is bigger)(I also did not use all the parts they sent because they are for a car), two wire cables (350 lb. working strength), 4 cable clamps, 2 four-inch pieces of black pipe, 4 pipe caps, 8 locking nuts, 2 turn buckles 2 return springs(to pull the brake cam levers back) and some nuts and bolts. Remember all these things will have to be fitted, so it will take time and some trial and error.
The black Iron pipe is my design to make the brake rod collapsible when I apply the rear brakes while using my brake pedal (see the drawing for details on how to make them). Since I added a Muncie 3 speed overdrive gear box to the truck with a high-speed gear set (5to1) to the rear end, that increased my speed to 40 miles/hour and also added a true neutral to the drive train, I needed to increase my braking power and add brakes to the rear end. When I push the foot brake pedal, the rear brakes are applied as well as the transmission brake. I adjusted the rear brakes to be applied just before the transmission brake is applied. The truck stops much quicker, and increase my braking power by 3 times. I also wanted to keep my brake rods in their original position, so I added the cables to the equalizer system. I know I could have just moved the brake rods (if lengthen) to the equalizer but I still liked the look of the brake rods on the outside. Also having rods and cables gives me a backup braking connection. Since I added the cables to the equalizer system and left my brake rods on the hand brake system, I need the rods to collapse on themselves when I push in my brake pedal in. So, the black pipe system on the brake rods makes this all possible for this to work VERY IMPORTANT THE ROD NEED TO BE ALIGNED SO ALL THE PARTS WORK SMOOTHLY. Here are a few pictures of the braking system.
This picture shows the connection from the brake pedal, the tang welded on the bottom of the brake pedal, then the rod adjustment to the top of the brake equalizer. You can also see the turn buckle and cable.
This picture shows the bottom of the equalizer system, the turn buckles for adjustment, and the cable connection.
This picture shows the cable rod connections to the radius rods. VERY IMPORTANT THE ROD NEED TO BE ALIGNED SO ALL THE PARTS WORK SMOOTHLY I used an eye bolt to connect the brake rod holder and to hold the brake rod. It also made adjusting the brake rod alinment easy.
This is the collapsible pipe system. VERY IMPORTANT THE ROD NEED TO BE ALIGNED SO ALL THE PARTS WORK SMOOTHLY The rod pushes in from the back. The brake rod has to be cut into and about 1 1/2 inched to be taken out. Both ends of the cut rod will need to be threaded for the lock nuts. When the brake lever is pushed forward or the brake pedal is applied, the rod will collapse on itself. When the brake lever is pull back to apply the parking brake, the rod will pull out and the nuts inside will hit the caps to make the brake rod solid again to apply pressure to the brake cam lever.
The cable fits in the Y of the brake rod. The return spring is attached to the base of the grease cup and to the pin of the brake cam lever.
I have had several people ask/email me about making my parking/emergency brakes into service brakes instead of using rear outside band brakes. First it was not my idea, I heard a rumor about another person doing it on his TT truck, but did not know how he did it. Also, I think I read that you can do it on the 26/27 Model T. I did this because on the Model TT truck, you have big brake drums with four lined brake shoes, so it should work just fine if the drums and brake shoe linings are good. The parts I used for this project was: a brake equalizer kit (bought this off an individual, I think venders have this too)(the tang they send, that is to be welded to the bottom of the brake pedal, will be too short, you will need to make a longer one because the TT frame is bigger)(I also did not use all the parts they sent because they are for a car), two wire cables (350 lb. working strength), 4 cable clamps, 2 four-inch pieces of black pipe, 4 pipe caps, 8 locking nuts, 2 turn buckles 2 return springs(to pull the brake cam levers back) and some nuts and bolts. Remember all these things will have to be fitted, so it will take time and some trial and error.
The black Iron pipe is my design to make the brake rod collapsible when I apply the rear brakes while using my brake pedal (see the drawing for details on how to make them). Since I added a Muncie 3 speed overdrive gear box to the truck with a high-speed gear set (5to1) to the rear end, that increased my speed to 40 miles/hour and also added a true neutral to the drive train, I needed to increase my braking power and add brakes to the rear end. When I push the foot brake pedal, the rear brakes are applied as well as the transmission brake. I adjusted the rear brakes to be applied just before the transmission brake is applied. The truck stops much quicker, and increase my braking power by 3 times. I also wanted to keep my brake rods in their original position, so I added the cables to the equalizer system. I know I could have just moved the brake rods (if lengthen) to the equalizer but I still liked the look of the brake rods on the outside. Also having rods and cables gives me a backup braking connection. Since I added the cables to the equalizer system and left my brake rods on the hand brake system, I need the rods to collapse on themselves when I push in my brake pedal in. So, the black pipe system on the brake rods makes this all possible for this to work VERY IMPORTANT THE ROD NEED TO BE ALIGNED SO ALL THE PARTS WORK SMOOTHLY. Here are a few pictures of the braking system.
This picture shows the connection from the brake pedal, the tang welded on the bottom of the brake pedal, then the rod adjustment to the top of the brake equalizer. You can also see the turn buckle and cable.
This picture shows the bottom of the equalizer system, the turn buckles for adjustment, and the cable connection.
This picture shows the cable rod connections to the radius rods. VERY IMPORTANT THE ROD NEED TO BE ALIGNED SO ALL THE PARTS WORK SMOOTHLY I used an eye bolt to connect the brake rod holder and to hold the brake rod. It also made adjusting the brake rod alinment easy.
This is the collapsible pipe system. VERY IMPORTANT THE ROD NEED TO BE ALIGNED SO ALL THE PARTS WORK SMOOTHLY The rod pushes in from the back. The brake rod has to be cut into and about 1 1/2 inched to be taken out. Both ends of the cut rod will need to be threaded for the lock nuts. When the brake lever is pushed forward or the brake pedal is applied, the rod will collapse on itself. When the brake lever is pull back to apply the parking brake, the rod will pull out and the nuts inside will hit the caps to make the brake rod solid again to apply pressure to the brake cam lever.
The cable fits in the Y of the brake rod. The return spring is attached to the base of the grease cup and to the pin of the brake cam lever.