I’ve owned my 68 for two years. Previous owner converted to front discs. Multiple issues, which I am now attempting to repair. First, incorrect booster, which I replaced with a rebuilt Midland. Second, the rear brakes do not appear to engage. Third, the brake warning light on the dash would be on all the time (currently disconneted). The distribution block appears to be original for drum brakes, and an inline adjustable proportioning valve (not a Wilwood) installed for the rear brakes. I removed the distribution block and the internal valve appears stuck with full fluid sent to the front disc brakes.
I think I need to replace the distribution block. WCCC currently does not have a distribution block for 68 drum brakes in stock. Will the Brake Distribution Block Assembly for Power Disc Brakes work for me. If so, should I remove and bypass the installed inline adjustable proportioning valve?
Im a strong believer of factory setup. So, If I read need a disc brake setup’ I think the 68 & 69 are the same. Issue might be fitting sizes of the steel lines on the car now.
I have a setup I rebuilt recently. Has the dist block & valve w/ lines. It also has a tested good switch for the light!
Be thorough, start with the size of rear wheel cyls. They are different sizes for different type of brake & options like motor size. Remove adjustable valve & old block.
The drum brake distribution block will work fine with the aftermarket proportioning valve. No connection between the idiot lamp and the lack of flow to the rear brakes. The light control only controls the light. No effect on braking.
Royce is correct. your setup will work just fine as it is. (drum distribution block and wilwood prop valve) The shuttle valve inside is only for the light on the dash, it does not affect flow.
Make sure you have a disc/drum master cylinder as they are different. check all your brake lines. The soft line from frame to axle is a common one to plug up and stop flow to the wheel cylinders. Also probably a good idea to replace or rebuild those wheel cylinders too if you have not already.
Thanks guys. If I could rebuild the drum distribution block, I would. Sadly, the cylinder inside won’t budge. At the moment, I am trying to get a working distribution block. Again, the question is “Will the Brake Distribution Block Assembly for Power Disc Brakes (which includes a proportioning valve) work for me. If so, should I remove and bypass the installed inline adjustable proportioning valve?” Your comments bring up other good points, though. I’ll check if the master and brake cylinders are appropriate for a disc/drum setup.
I, of course, realize the brake warning light switch will not affect braking, The reason the light is on all the time is because the distribution block cylinder is not centered and stuck.
After rereading your comments, I now see you are saying the the cylinder in the distribution block does not affect flow. If I have problems with the rear brakes engaging, then that issue is either the proportioning valve or the brake cylinder1s. I’m clear on that now. Learning every day! I still want a working distribution block. Thanks again
Every brake thread now makes me more and more solidified in knowing I did the right thing by going to manual brakes with the full Wilwood master cylinder and prop valve combo. I hated fighting the factory power brake setup.
Unlike various internet threads the distribution block brake switch does not affect flow to the brakes. It only controls the idiot lamp in the dash. That’s all it does. If your setup does not work right it might be as Bill says bad components but more likely something else is wrong. It could be the calipers are swapped side to side, or bad bleeding technique, or something else.