Brakes on my gbody
 

I change my Malibu to manual brake bought the kit from trz. I have nine inch rear with disc brakes. Is there anything else I have to do to make it work. Thanks

What all is included in the kit?

The master cylinder and plate for fire wall and the linkage rod for the brake petal. The rear is a spraker racing nine inch with gm calibers the brake petal feels good. But when I drive it it don’t stop like I want

Are you still using a stock proportion valve?

Also check your lines. The rubber lines going from the steel line to the calipers can collapse inside.

I put new rubber line on front. I am still running the stock proportion valve.

Get a adjustable proportion valve, the stock valve is not set up properly for a front and rear disc manual brake setup. its probably not sending enough pressure to the rear calipers.
have you done any hard braking to see what wheels lock up first?