1990 Ford Ranger • 21,000 miles

ABS brake fluid proportion valve repair, I have put a new not rebuilt master brake cyl. In, still no brake fluid to rear brakes. Lots of fluid pressure to both front brakes. Both brake and ABS lights are on, is there a repair avaliable anywhere?
November 3, 2012.

The proportioning valve may be the issue.

This multi-function hydraulic control unit consists primarily of a pressure differential valve, brake lamp warning switch and a proportioning valve. A pressure differential shuttle and/or metering valve are also incorporated with some valve applications.
The metering valve delays front disc brake effectiveness until the rear brake shoes contact the brake drums. The proportioning valve regulates rear hydraulic system pressure to prevent rear brake lock-up. The pressure differential valve senses hydraulic system pressure and will activate the brake lamp warning switch if a pressure loss occurs. The pressure differential shuttle bypass feature provides full rear brake application if front hydraulic system pressure is significantly reduced.