Jekit 4 Piston Caliper 380x28mm Fit Toyota ALPHARD 20" Wheel

Product Description

Jekit 4 Piston Caliper 380x28mm Dual Caliper fit Toyota ALPHARD

Basic knowledge of brake caliper

1. Since the multi piston brake caliper is refitted and upgraded, it is natural to choose the multi piston brake caliper. What do you mean by the double piston, four piston and six piston brakes? The piston here refers to the piston on the piston disc brake caliper. It is a device pushed out by oil pressure to force the brake pads into close contact with the brake disc. It is named after its shape like a piston. Double pistons means there are two pistons, four pistons are four, six pistons are six, that is, three on one side, just like you push something with six fingers with both hands.

However, for the same vehicle, replacing the original single piston caliper and upgrading the multi piston caliper will not improve the braking force. The whole braking system has not made major changes. Only upgrading the number of pistons will not improve the braking force. The disc brake relies on the pressure of brake fluid to push the piston to realize braking. The original single piston monopolizes all the pressure and the four pistons of the upgraded four piston caliper evenly distribute the pressure. Therefore, for a single piston, the pressure is smaller than that of the original single piston; The increase in the number of caliper pistons does not improve the braking force, but the way of pressure distribution changes and becomes more uniform. The advantage of more pistons is that the braking force can be more evenly dispersed while maintaining the total braking force.

If only a single point force of a single piston is used, it is easy to break the brake disc. The reason is very simple, that is, the pressure formed at a single point is too large; The use of multiple pistons disperses all braking forces more evenly, from single point force to multi-point force, which is of great benefit to protect the brake disc from cracking and prevent local overheating.

2. Multi piston size distribution and acceptance principle. At present, the brake calipers we can contact in the market are divided into large and small pistons, six pistons, one side is generally small, medium and large, and four pistons are small and large. In this way, we have scruples about the size, distribution and weight of the brake caliper. In addition, the oil supply pressure of the brake master cylinder is also considered. Moreover, the well-designed brake calipers have different thrust and sequence for multiple pistons when the pressure applied by the brake pedal is different, which is the difference between good and bad brake linearity. For example, Brembo's big six pistons have always been known for their strong braking force and good braking linearity in the modified brake Market. Their design principle is simply realized in this way. When the brake pedal is lightly pressed, the sequence of pressure applied by the six pistons as a whole is small, medium and large, and the strength of the pistons with the same size on the opposite side is the same. However, it does not mean that only the small piston has strength, but the proportion of pressure applied by the small piston is more heavy. In this case, You won't feel that as long as you gently press the brake pedal, you will brake very quickly. Then, with the increase of the strength of the brake pedal, the middle piston and the large piston will increase the pressure accordingly, so as to achieve the maximum braking effect. This is the basic principle of the linear origin of braking. Of course, there is a more complex work theory

3. Differences in manufacturing process of calipers. Calipers are first divided into two types, integrated and split. In addition, calipers are also divided into casting and forging, including different materials of pistons, which are also divided into steel, aluminum alloy and titanium alloy. It is easy to distinguish the split caliper from the integrated caliper. The split caliper will be above the caliper, and you can see the splicing line. The integrated caliper will not have this splicing line. What is the difference in specific use? In extreme cases, including high temperature, split calipers will expand outward. This reduces the braking force. The strength and material of the integrated caliper also depend on the strength. The expansion and contraction of high-strength thermal expansion and cold contraction is small. The higher the strength is, the greater the braking force is, and the less it will deform in a harsh environment. The cost of one-piece forged caliper is several times higher than that of split caliper, and the manufacturing process is very complex, which is the main reason for its high price. The second is the piston. The piston is made of a variety of materials, some of which are steel and some are forged aluminum alloy. The top pistons are titanium alloy. The titanium alloy piston for competition will also have many heat dissipation holes and no dust-proof rubber pad. It needs regular maintenance to remove the brake ash. The material of the piston will affect the temperature conductivity of the brake skin to the brake oil circuit. The worse the material is, the stronger the temperature conductivity is. The piston with weak heat insulation capacity will cause the brake oil to boil very quickly. Once the brake oil boils, the braking force is equal to 0.