Jekit car AMG brake caliper 360x36 kit with custom color bell

Synthetic brake oil can be divided into alcohol ether type, ester type and silicone oil type, but the most used are alcohol ether type and ester type.

1. Alcohol ether type:

common in dot3. The chemical composition of alcohol ether type is low polyethylene glycol or propylene glycol. Low polyethylene glycol or propylene glycol has strong hydrophilicity, so its water content will gradually increase during use or storage. Because the boiling point of brake oil will decrease with the increase of water content, its braking performance will decrease. When you find that you need to step on the brake hard to brake, a likely reason is that the water content of the brake oil is too high. Therefore, DOT-3 brake fluid is basically not recommended by major engine manufacturers.

2. Ester type:

common in DOT4. Ester type is to add a large amount of boric acid ester on the basis of alcohol ether type. Borate ester is formed by esterification of low polyethylene glycol or propylene glycol with boric acid. The boiling point of borate ester is higher than that of low polyethylene glycol or propylene glycol, so its braking performance is better. Borate ester also has strong moisture resistance. It can decompose the absorbed water, so as to slow down the decrease of boiling point caused by water absorption. Therefore, the ester type has better performance and higher price than the alcohol ether type. At the same time, it also gradually replaces the alcohol ether type brake fluid. Therefore, DOT-4 is a common synthetic brake fluid on the market.

3. Silicone oil type:

common in dot5. The chemical composition of silicone oil type is polydimethylsiloxane. Its boiling point is the highest among the three categories, so the price is also the most expensive. Because polydimethylsiloxane has strong hydrophobicity, it hardly absorbs water at all. However, because of its strong repelling ability to water, the water entering its pipeline can not be miscible with it, but exists in water phase. Because the boiling point of water is very low relative to brake oil, this immiscible water will lead to a sharp decline in braking performance. Therefore, the application range of silicone oil type is narrow. It is generally applicable to specific people who need to refit sports. It has good short-term braking performance, but compared with DOT-4, it has a service life of almost half a year, which is not in line with the mass consumer group.

4. Modified borates are used in dot-5.1.

Many riders easily confuse it with dot-5. In fact, I tell you here that the two are completely different. One is competitive oil, and the other is long-term oil for ordinary cars. Although it surpasses DOT-4 in some performance in terms of data, it is rarely put on the market for the time being due to domestic technology and some of its specific performance, such as corrosion to pipelines, and even if it is available, the price is particularly expensive.