Twin Stop – Installation Instructions

Handy Items To Have For Installation: Along with your commonly used mechanics tools the following items will proof to be handy: pins, trouble light, wire, exacto knife, tape

Part A: Determining Position of the Instructors Brake

This will be as high on the firewall as possible the limitation being the heater ducts, and as far to the right as possible the limitation being the wheel well. The “Passenger Side Hinge” and the first 6″ of “Cable Housing” should not be obstructed so that it can freely move through its 15-degree arc: Also the “copper stop” on the cable should be unobstructed so it can move freely. Insert a pin into the carpet to mark the position of the “Upper Mounting Hole”.

Depending on the floor angle and configuration of your vehicle it may be desirable to elevate the lower section of the base: This can be done by cutting and bending the piece of blank metal provided or putting a piece of wood that is the proper thickness under the bottom of the instructor’s brake.

Thread the cable into the “Cable Housing” and determine how the it will be run over to the driver’s side: The path needs to be as straight as possible.

Part B: Place “Clamp Assembly” On The Brake Pedal

Place the “Clamp Assembly” on the cars brake pedal as close to the brake pedal rubber as possible (fig. 1) and (fig. 2).

Part C: Determining Position Of The Driver’s Side “Floor Assembly”

The “Floor Assembly” should be positioned to the right or left so that the “Round” of the “Clamp Assembly ” will just come along side the hinge pulley upon complete brake deflection. Also the Driver Side “Floor Assembly” must be positioned up or down on the firewall so that it matches the position of the “Clamp Assembly” on complete deflection. See various views (fig. 2) and (fig. 3).

Finding the proper position is not easy and takes some care and patients. Start the car so that the vacuum of the cars power brakes allows the pedal to move to the floor as much as possible. Take the “Floor Assembly” with your right hand and push down the cars brake pedal with the other: Move the pedal down a view times and project where the “Cable Assembly” will reach the floor upon complete pedal deflection: Move the “Floor Assembly” beside this projected position so that upon complete brake deflection the position of the drivers side parts will look similar to what is shown in (fig. 2) and (fig. 3). Turn the “Floor Assembly” so that the hole for the “Cable Housing” is pointed in the direction of the intended cable path that was determined in Part A (fig. 2). If you are knowledgeable in auto mechanics it is also possible to take the guess work out of this by opening a bleed screw and actually pushing the pedal to the floor.

Mark the position; pins inserted into the carpet is often a good way to do this.

(fig 2) Proper Assembly And Positioning Of Driver’s Side Parts

Part D: Plan and Install Driver’s Side “Floor Assembly”

Once the proper position is found determine what problems will be encountered in mounting; don’t be to discouraged if you find that some car component is getting in your way, probably the steering column X/#?/^^##. This being the case it is up to the installer to custom make a bracket by cutting, bending and drilling the blank piece of metal provided: This can be mounted with self tapping screws fastened into the cars firewall in safe locations and the drivers side floor assembly mounted to this using the carriage bolts that came with the “Mount Plate” (in this case the “Mount Plate” is discarded) (fig. 3).

This is the critical part of a proper installation: The unit cannot be expected to work properly if the “Floor Assembly” is not at its proper position.

Drill holes through carpet and under padding (or cutaway under padding and pull away carpet; this will depend on the type of vehicle and what you find better), drill and manufacture optional bracket as in (fig. 3), and install “Floor Assembly”. It will be easier to remove the “Mount Plate”, fasten it along with the carriage bolts first and then fasten the remainder of the “Floor Assembly” over this. If the custom made bracket is being used it is best to mount this to the floor first (before drilling the holes for the “Floor Assembly”) and then go through the positioning exercise as described in Part C; this time marking the “Floor Assembly” position on the custom made bracket. The bracket can then be removed, the holes drilled for the floor assembly, the assembly mounted to this, and the bracket reinstalled in the car. See tips # 2 and 3 mentioned above.

Part E: Install Instructors Brake

Using an exacto knife cut an approximate 3/8 inch diameter “carpet hole” in the carpet at the pin location determined in Part A. If there is easy access to the under side and if you have the aid of an assistant you may prefer to install the instructors brake using a bolt and a nut on the under side; but in most cases, due to limited access on the under side, it will be necessary to use the “Stud Plate” and “¼ inch Carriage Bolt” fastened with self taping screws (fig. 1).

Mark the position of the “carpet hole” onto the under padding. Pull back the carpet and using an exacto knife cut away the under padding to about the size of the stud plate. Replace the carpet and project the “carpet hole” onto the cars metal firewall with a black marker. Hold the large hole of the “Stud Plate” over the mark and drill the hole for the first self-taping screw: Be careful, read the important tip # 2 mentioned before. Drill and fasten the remaining screws: Remember important tip #3 mentioned before. Now unfasten the screws and punch the “¼ Inch Carriage Bolt” into the “Stud Plate” and reinstall. Replace the carpet with the carriage bolt sticking out through the “carpet hole”. Install the instructor’s brake over this carriage bolt stud. Self-tapping screws can then be used in the bottom two holes along with the optional elevation bracket or wooden block that you may have decided on in Part A.

Part F: Final Assembly

Route the “Cable Housing” to the other side according to the path determined in Part A. The “Cable Housing” will have to be cut and deburred to the length needed.

Working from the driver’s side use the right edge of a piece of tape to mark where the “Cable Housing” will have to be cut. (The right edge is used because if the cut is made on the wrong side of the tape it will be to long and a second cut can be made instead of the housing being scraped.) When determining the length of the “Cable Housing” leave 3/8 of an inch to go into “Driver’s Side Hinge”. Make sure the housing is not cut to short: It should be well seated into the hole at each end with out being stretched. It is better the housing is a little longer than to short.

When the housing is marked remove it from the car and take it to a workbench. Cut the housing with a pair of wire cutters leaving about 1/8 inch longer for the finish grinding. With an exacto knife trim off ½ an inch of the black vinyl outer casing. Using a bench grinder grind the metal coils down flat: Have a cup of water near by to keep the housing cool thus avoiding as much as possible melting the inner plastic sleeve. (A file can be used for flattening the coils but grinding is recommended.) Clean the hole with a 5/64 drill.

Replace the cut “Cable Housing” and poke the cable through hole of the “Drivers Side Hinge”. Route the cable around “Clamp Assembly” according to (fig. 2) and under the squash plate according to (fig. 4). Pull the cable through to allow dual brake to come to its upright position and tighten the “Squash Plate Nut”.

(fig 4) Proper Routing Of Cable Under “Squash Plate”

Fasten the “Installation Spring Strap” about half way up the brake arm; drill a small hole in the bottom edge of the dash; bend the “Installation Spring” as needed and hock between these locations (fig. 1). This spring is installed to offset the pull that the cable applies to the brake pedal so that it stays all the way up and does not activate the brake lights. Or, If there is difficulty finding a place under the dash to fasten the spring you may want to consider eliminating this step by reducing the tension on the cable: This can be done by sliding the spring off the pin on the, main, instructor’s side unit and tying it back so that it doesn’t interfere with the working of the instructor’s brake. If the housing path is fairly short and strait the unit will work perfectly well with the reduced cable tension.

Part G: Test

Road test the installation from the driver and instructor’s side: Check to make sure the brake lights are coming off.