70 C10 drum to disk conversion

[tobascofred]

I have purchased a SSBC A126-71 front drum to disk brake conversion kit for my 70 C10. I have two questions -

1) While the list of required tools does not mention needing a drill, in the instructions they state that a new 3/8 inch hole must be drilled in the brake pedal one inch below the existing hole - does anyone know why this is needed / if it is really required?

2) When I removed the old vacuum booster, there was a rectangle of ancient insulation matting between the bracket and the firewall - it is trashed. I assume that it is supposed to make a "seal" to keep engine bay fumes out of the cab. Has anyone ever used some other sort of a "seal"?

[vortech71chevy]

The one inch drop on your pedal is 100% necessary, without your brakes will be very awkward, touchy, and frankly dangerous. I thought I could bypass it, but basically my brakes would go from nothing to max pressure way to fast, resulting in very hard abrupt braking... no bueno.

[tobascofred]

Thanks for the info, vortech71chevy. Did you drill your pedal in place or remove it? I cannot see exactly how to remove it and drilling it in place looks like a real pain?

[NC_John]

Was there a reason why you had to change the geometry of the pedal and pushrod for that conversion? I just replaced my master cylinder with a wilwood unit. I replaced the factory pushrod on my '70 with the wilwood one (bought the kit) using the factory hole on the brake arm and it seems to be fine. (I haven't filled it with fluid yet, I need to make my new lines)

[70STOVEBOLT]

There should be a rubber cone-shaped boot that goes in the round hole that the brake pedal pushrod passes through to seal the firewall.

[tobascofred]

Originally Posted by 70STOVEBOLT

There should be a rubber cone-shaped boot that goes in the round hole that the brake pedal pushrod passes through to seal the firewall.

Thanks 70STOVEBOLT - mine does not have one - I will have to see if I can make one somehow or find one to buy.

[70STOVEBOLT]

I believe they are reproduced. I am sure Wes (Classic Heartbeat) can fix you up, or any of the other board vendors.

[tobascofred]

Originally Posted by NC_John

Was there a reason why you had to change the geometry of the pedal and pushrod for that conversion? I just replaced my master cylinder with a wilwood unit. I replaced the factory pushrod on my '70 with the wilwood one (bought the kit) using the factory hole on the brake arm and it seems to be fine. (I haven't filled it with fluid yet, I need to make my new lines)

Don't know if this is a variable, but my truck / conversion kit is power brakes / with a replacement vacuum booster.

[tobascofred]

I finished the front drum-to-disk conversion last night (as well replaced the rear springs and all four shocks).

All in all this conversion was easier than the other two that I have done (first on 65 Chevy II, second on 71 Mustang). Stopping power and control is vastly improved. And no, I did not drill the extra hole in the brake pedal - I thought I'd try without it and do it if the brakes did in fact become too touchy to use as was suggested. No sign of touchiness using the stock linkage hole.

For the issue of "plugging" the hole in the firewall where the linkage passes through - I ended up just taking a rectangular piece of some very stiff industrial carpeting, slit a vertical slot for the linkage to pass through and mounted it between the booster bracket and the firewall.

[NC_John]

Originally Posted by tobascofred

I finished the front drum-to-disk conversion last night (as well replaced the rear springs and all four shocks).

All in all this conversion was easier than the other two that I have done (first on 65 Chevy II, second on 71 Mustang). Stopping power and control is vastly improved. And no, I did not drill the extra hole in the brake pedal - I thought I'd try without it and do it if the brakes did in fact become too touchy to use as was suggested. No sign of touchiness using the stock linkage hole.

For the issue of "plugging" the hole in the firewall where the linkage passes through - I ended up just taking a rectangular piece of some very stiff industrial carpeting, slit a vertical slot for the linkage to pass through and mounted it between the booster bracket and the firewall.

Thanks for the update. I got all my brake fittings together on Friday but got nowhere trying to bend and flare lines. Couldn't bend the lines in a way that I was happy and the flares looked like crap. Even struggling trying to figure out where to mount the line lock.

I'm getting some softer tubing (nicopp) and a better flaring tool and will try again this weekend. The good news is my suspension parts are all in, stuff is cleaned and painted. Once the brake lines are in, it should be quick to finish.

[tobascofred]

Line lock as in a manual front brake locker (photo) or the proportioning valve (photo)? As you can see, I mounted my prop valve at the rear brake line splitter - could not figure out a clean way to found it in the engine compartment. I hope that it is pretty well protected by my exhaust pipes.

I brake the rigid line to the left rear wheel muscling the prop valve into place and walked the dog up to the local auto parts store and bought a length of pre-flared / made rigid line. The reason - I bought a spool of stainless brake line, a bending tool and a flaring tool when restoring a 71 Mustang some years ago. For me, it is impossibly to make a usable (leak-proof) double flare with the stainless, or for any other brake line I've tried (never seen / tried on copper, maybe that should be soft enough to flare easily). Good luck with your project!

[tobascofred]

Odd, my pictures flipped! Well, hopefully you can make them out!

[NC_John]

My line lock is this one.

http://www.hurst-shifters.com/produc...yr=&md=&sm=&e=

The prop valve is mounted right on the master cylinder. I want to keep the line lock valve close but there isn't a lot of available real estate on that side of the firewall.