I replaced the shoes and rear wheel cylinders blood them several times had brake pressure . Thrn I replaced the brake check valve on the booster after starting the truck did not have adequate brake pressure???????

 

Is that the vacuum check valve on the booster??

Did you adjust the rear brakes??

 

The check valve is on the brake booster and yes I drove the vehicle in Reverse to adjust the rear brakes

 

That method will take quite a while to get them adjusted properly. That's why there are little 'windows' in the backing plate, so you can manually adjust them after a brake job.

 

AKA the black push in plug for the "window" at the bottom of the backing plate. You need a "brake tool" or screwdriver to adjust the star wheel until you feel resistance. I'm sure there are videos on you tube that show you how to do this.