Why is it not recommended to mix and match brake levers and calipers between different brands or models?
The first is the problem of brake fluid. If different brands use different brake fluids, the seals used will be quite different. For example, the brakes using DOT oil and the brakes using mineral oil are different in the selection of seals. There is a big difference because the DOT requires a stronger corrosion resistance of the seal.
The second reason is the hydraulic ratio. if the piston area of your brake lever is fixed, then if the piston area of the caliper you replace is larger, you must consider whether the capacity of your brake lever piston can drive a larger caliper.
For example, if the brake lever corresponds to a two-piston caliper, replacing the four-piston caliper with a larger diameter and area at this time may cause the problem of excessive stroke. The reverse is also the same. If the caliper area used is smaller, the brake lever stroke may be too short. This will directly affect the linear performance and braking strength of the brake design.