This brake proportioning valve will fit S-10 GM vehicles, trucks etc. from the 90's. This is made of aluminum and is for disc/drum set up.
The original was made in iron. It was re-called. This was due to the iron deteriorating & causing damages to the accumulator ball. What happens is the Iron attacks the glue that attaches the seal to the steel ball. When this happens the diaphragm looses it charge. If you are replacing your accumulator ball or power master this is a must to keep your oil clean & prevent future failures.
If you find yourself replacing your accumulator ball to a lack of a charge every few years & the oil is black this will solve your problem.
This will not fix yourPower master. This does replace a faulty proportioning valve. If your Brake light comes on this is 1 of the 3 reasons it will. Please diagnose your system properly or get a manual on how to service your power master that we carry on the site.