I think you're a little misinformed about brakes. Drum brakes on the front of older cars were of the "duo-servo" design and are considered to be "self-energizing". What that means is the job of the smaller front shoe is simply to grab the drum and try to rotate with it, and in so doing, it pushes on the star wheel adjuster which pushes the bottom of the rear shoe into the drum. The wheel cylinder pushes the top of the rear shoe into the drum, so you have two forces pushing on the rear shoe. That's why the rear shoe is larger and why it's called a duo-servo brake. They are very effective with little pedal effort.
Disc brakes are relatively ineffective. To get the same stopping power we added a power booster. The advantage to disc brakes is they're always in adjustment, and they squeegee off water after driving through deep water. That deep water can get into a drum, but then there's no where for it to go when the brakes are applied. That can lead to brake fade for a long time before it clears up.
The more important issue here is you're doing a lot of stuff that can land you in a lawsuit. Your brake system has been very carefully designed to provide balanced braking, front-to-rear. Normally you seriously mess that up when you lower a car or raise a truck because the center of gravity has been changed, and that affects weight transfer to the front. Now you want to go one step further than most unknowing owners and upset that balance even more by installing weaker front brakes.
With different wheels, there's a real good chance you're going to change a non-adjustable alignment angle called "scrub radius". If you stand in front of the car and draw an imaginary line through the steering pivots, in your case the lower ball joint and the upper strut mount, that line will intersect the road surface close to the middle of the tire tread. If you want me to, I can get into the alignment and braking theory when I get back home next Sunday night, but basically that affects comfort while driving long distances, and most importantly, controlled braking when one half of the hydraulic system fails. Switching to a tire with a larger diameter, different width, or a different offset, including adding spacers, changes scrub radius, and that adversely affects steering response, directional stability, and braking distance. These are the things lawyers and insurance investigators know all about. They will convince a jury that YOU were partly at fault for the crash when the other guy ran the red light because you were less able to avoid it, and they will be right.
You can be sure they will find the modified brakes on your car too and will use that against you. The other problem is that while there are often two different brake systems that were used on one car model, they are both an integral part of the systems they were designed into. One is considered the "standard" brake system and the other is the "heavy duty" system. Most of the time the smaller systems use a smaller bolt pattern for the wheels, or a four-bolt wheel instead of a five-bolt, so even if you could degrade your brakes, your wheels wouldn't bolt on to the smaller hub.
Tuesday, July 7th, 2015 AT 7:34 PM