Proportioning Bypass Valve Inspection [Without Abs]

WARNING: This page is about a different car, the 2005 Mazda MX-5 Miata. However, it is still accessible from the selected car via links, so may be relevant.

Connect the SSTs and the adapters to the brake pipes as shown in Fig 1.
Bleed the air from the brake system.

Fig 1: Connecting SSTs And Adapters To Brake Pipes
Courtesy of MAZDA MOTORS CORP.

Measure the fluid pressure from the master cylinder and to the rear brakes.

If not as specified, replace the valve component.

Fig 2: Master Cylinder And To Rear Brakes Fluid Pressure Specifications

Courtesy of MAZDA MOTORS CORP.

Master Cylinder Pressure - Rear Brake Pressure Graph

Fluid pressure kPa {kgf/cm2, psi}
A	A'	B	B'
3,923 {40, 569}	3,923 {40, 569} +/-294 {3, 43}	5,884 {60, 853}	4,844 {49.4, 702} +/-392 {4, 57}