Full List of Products Posted on June 8th, 2015 by vapro

What are the most significant Caliper Features?

Kodiak has standardized on a caliper with a single 2¼” diameter piston for the 3.5k, 5.2k, and 6k axles.

Kodiak has standardized on a caliper with a single 2½” diameter piston for 7k and 8k axles.

Kodiak has standardized on a caliper with a single 33/8” diameter piston for 10k axles.

What are the most significant features of the Kodiak Rotor?

VENTILATED DESIGN: Rotor surface temperatures which rise rapidly from repeated stops can be minimized by using a ventilated rotor to accelerate heat transfer from the rotor to the surrounding air. During heavy braking, non-ventilated rotors may overheat, causing accelerated brake pad deterioration and accelerated rotor surface wear.

ROTOR MATERIAL: Cast iron is the preferred material for rotors as is evidenced by the fact that 100% of the automotive rotors are made from cast iron. Cast iron has superior wear characteristics at high temperature, and has a favorable friction coefficient to optimize stopping power. Kodiak’s cast iron rotor is manufactured to SAE material specifications and furnished with a standard automotive finish or E-coated, or in some cases, Dacromet coated. Coated rotors minimize corrosion between the rotor and the hub face and between the rotor and the wheel.

Kodiak also furnishes 10″, 12″ and 13″ ventilated stainless steel rotors especially for the salt water boat trailer market. The stainless steel rotors are attractive to avid salt water boaters due to its aversion to salt water corrosion and low maintenance characteristics.

NOTE: Some rotors are manufactured from cold rolled steel plate. Rolled steel plate has inherent directional properties due to the effect the rolling operation has upon the granular structure of the steel. After the rotors have been heated/cooled by heavy braking, these directional properties tend to manifest themselves by warping to some degree. Due to the thin cross section of some of these rotors, they cannot be “turned” to correct the problem.

What are the major advantages of Disc Brakes?


  1. Fewer Moving Parts
  2. Longer Life due to fewer moving parts and more effective heat dissipation
  3. Easy access for cleaning, maintenance, replacement and inspection


  1. Self-adjusting calipers result in smoother braking
  2. Better braking performance due to less dirt, water, or rust contamination
  3. Less sensitive to premature lock-up or wheel skid
  4. Fade resistant

Lower cost over the expected life of the trailer

What are the most significant features of the Kodiak Disc Brake System?

The Kodiak Disc Brake System is a proven system that includes a rotor that fits over the axle hub*, combined with a caliper and mounting bracket that attach to the axle end assembly by bolting to the standard brake flange. The wheel studs are pressed into the hub only. The rotor is a loose fit on the hub, and is retained by the wheel, which, in turn, is retained by the wheel nuts. Removal of the rotor can be accomplished with little effort once the caliper has been removed. No machining is required prior to installation.

Kodiak disc brake rotors are sized as follows:

10″ Rotor which fits over the standard 545* hub.

12″ Rotor which fits over the standard 655 hub.

13″ Rotor which fits over the standard 865 hub.

NOTE: The term 545 refers to a 5 bolt hub with a 4.5″ bolt circle; 655 refers to a 6 bolt hub with a 5.5″ bolt circle; and 865 refers to an 8 bolt hub with a 6.5″ bolt circle.

* For situations where it is preferred, Kodiak has also developed integral (one piece) hub/rotors for the 3.5k, 5.2k, 6k, and 7k axles. Contact Kodiak for more information.

Why is a reversing valve needed on surge brake actuators when installed on a trailer disc brake system?

For surge braked trailers, a reversing valve is recommended to facilitate backing the trailer. This is necessary because disc brakes function equally well in either direction, unlike uni-servo drum brakes.

Note: Uni-servo drum brakes need very little hydraulic pressure to activate them while going forward, but a tremendous amount of pressure is required to operate the brakes in reverse. Therefore, many users simply overpower drum brakes when backing up.


Most surge brake actuators require the installation of a reversing solenoid by the trailer manufacturer. These solenoids are energized by connecting them to the tow vehicle’s back-up light circuit. The solenoids come in two types:

Normally Open – This solenoid valve is installed “in-line,” normally at or near the master cylinder.

  1. Advantages:
    1. Quick and easy to install.
  2. Disadvantages:
    1. If trailer is stopped in a downhill attitude, some positive pressure may remain in the brake line. When the back-up light is energized, the solenoid valve merely “traps” the pressurized brake fluid, which may prohibit backing up the trailer.
    2. If trailer hits any significant object (such as a curb) while in the process of backing up, the entire force of this impact is transferred to the master cylinder piston (seal). A seal could be ruptured in this manner.

Normally Closed – This solenoid valve is typically plumbed from a “Tee” that is screwed into the master cylinder outlet or, alternatively, the solenoid valve may have three ports. From the valve, a “return line” must be installed to dump the brake fluid back into the master cylinder reservoir.

  1. Advantages:
    1. Eliminates the problems listed in b(i). and b(ii). above.
    2. Some surge brake actuators may be purchased with a normally closed valve installed by the factory.
  2. Disadvantages:
    1. Requires a few additional fittings and a short length of brake line.
    2. Master cylinders in some surge brake actuators are not “plumbed” to accept a return line.


  1. Solenoid valves may be one wire (grounded case) or two wires (ungrounded case). On a two wire model, generally either wire can be grounded and either wire may be connected to 12 vdc (i.e., polarity is not a problem).
  2. Solenoid valves should have an “in” and “out” marked on the housing. This configuration must be observed when piping a solenoid valve (i.e., it will not work properly otherwise).
  3. Older hydraulic drum brake systems required a 10 – 12 psi residual pressure be maintained in order to keep the wheel cylinder piston seals flared. To accomplish this, many surge brake actuators have installed a small diaphragm type check valve just inside of the master cylinder output port.

Disc brake systems must not be subjected to a 10 – 12 psi residual brake line pressure (the brakes will overheat). Therefore, the diaphragm (if installed) must be perforated with an ice pick or awl prior to installing and operating a disc brake system.


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Ft. Worth, TX 76118
