Hello All, Can someone help me out with a recent issue I'm having.. 68 442 convertible. Last winter I installed new upper, lower ball joints/ bushings/inner outer tie rods. New tires and alignment. By the end of last summer I started started feeling a little shake in the front end. Turns out The non disk brake rims (SS1) were hitting the calipers. Why now I am not sure. The wheels came with the car and i drove for 2 years without issue. Not sure what I have to begin with so that's where I'll start. Looks a lot like a 69 setup. Any input would be appreciated. Greg






these are older pics of what i have.

 

That looks like the goofy aftermarket kit that is supposed to clear 14" drum brake wheels. It's crap. The factory caliper brackets have ears that extend along the sides of the caliper to keep it from cocking as the pads wear. Even the original Astro Van installation of those calipers has this guided feature. This half-fast aftermarket bracket doesn't. The result is that the offset loads on the caliper are only taken by the rubber mounting grommets, which were never designed for that. This is yet another example of how most aftermarket disc brake kits are poorly engineered. Personally I'd pitch this crap and get a set of the 69-72 OEM-style calipers and brackets. Yes, your current wheels won't clear. Your car, your brakes, your call.

In the photos, OEM caliper brackets on the top, crappy aftermarket on the bottom. Your brackets are even worse because the pins on those calipers only bolt to the inboard side of the caliper. By the way, your rotors are also smaller in diameter than the OEM 11" rotors, which means less braking force. You be the judge.

 

OK Joe, In the scrap drum they will go. I had one instance of white knuckle stop and the brakes faded away as the truck got closer. I put on a set of ssII to get me to the shop and the whole system will get changed out with OEM. My next decision is should I keep the combo valve or go with something else. I am not sure how they are adjusted and feel it would be more simple to install a distribution block that is calibrated to work correctly. Please correct me if I'm overthinking this or just plain wrong. Thank you for the help. Greg

 

Also forgot to add I have drums in the back Greg

 

Do not confuse a distribution block with a proportioning valve. They are two separate devices with very different functions. Also do not confuse either with a metering valve. Few people understand that the factory designed and tested these brake systems to be safe under all driving conditions. One tenet of that is to prevent premature rear wheel lockup, which can cause the back of the car to come around in a panic braking situation. This requires the rear brake force to be limited with regard to the front. This is why the rear drum brakes nearly always use smaller shoes and smaller diameter wheel cylinders than the fronts. The same thing applies to disc/drum systems. On the 1967-70 A-body cars, Olds did NOT use a proportioning valve, they simply used even smaller rear wheel cylinders on cars with front discs to provide the correct front/rear balance. These cars did use a metering valve (also called a hold-off valve) mounted next to the master cylinder that served a different function. Starting with the 1971 cars, Olds transitioned to a combination valve that COMBINED (get it?) the distribution block, metering valve, and proportioning valve into a single part. This saved cost and minimized potential leaks. The problem with the aftermarket crap is that the factory used a number of different combo valves, each tailored to a specific car weight distribution. The aftermarket only offers the one-size-fits-none PV2 valve. The only certainty is that it won't be correctly calibrated for your application. Unfortunately it's about your only choice today.

 

Understood about the above once I wrapped my head around it. In the back of my head I thought it was adjustable. Here's the best pic of what I have. I figure I'll stay with what is there than risk new after market. As long as I can find a replacement part for the wire hook up. Also I do not remember a bleeder on the front like your drawing. I'll look better when home tonight. Thanks, Greg