My dad purchused a Cardone Master Brake Cylinder for his 1993 chevy truck and this was 4yrs ago. Come to find out today that the one AAP sold him was not the right one for the truck. It fit and worked but failed because our truck has booster power brakes and the cylinder that they sold us was for non booster power brakes. This past thursday I was in a accident with the truck causing over 800.00 in damage to my truck and not sure the damage to the other ladies vehicle. I was driving down the road and the lady infront of me was stopped with her left turn signal on, when I went to brake I had no brakes and no where to go. To find out today that it could have been prevented if AAP would have gave us the right cylinder 4yrs ago. I'm doing everything right now to get them to do something about it but they wont they say it was the right one. You tell me yeah there isn't much of a diffrence other then the size of the hole, Other then that they're not diffrent. But I talked to the manger of a diffrent store and she even stated that if you put a non booster cylinder on a booster brake system it will not last as long. I noticed the diffrence in them when I put the new one on today which is the one that should have been sold to us 4yrs ago.