Anyone do a disc brake conversion - need a winter project

Turdmagnet · Veteran Member

Anyone do a disc brake conversion - need a winter project

davelacourse · Poncho Master!

I did it on my 56 and it took braking from "come on, stop, that's it, stop, OK, stop now, please!" to "screech! STOPPED!"

Front discs only, rear brakes stock drums.

Dave

Turdmagnet · Veteran Member

Well my winter project has been off and on for quite a while but I'm finally starting to see the end of the tunnel. Disk conversion went really well - got a kit from Horton Hotrods in Milton and everything bolted up great. Tried keeping the drum/drum master setup I had done prior, but that was a crap show (others say they've made it work but I sure couldn't). Modified my old master mount to extend further under the floor so I could add a dual 7" booster to the setup - using a corvette m/c. Just need to get everything bled and hook up the vacuum. That's the question - where is the best place to pull the vacuum from? I'm still running the stock 239 flat head six.

Thanks

Turdmagnet · Veteran Member

Thought I'd post a couple of pictures on how things are progressing.

silver steak · Addicted!

Very nice set up. I am nearly at the point where I have to make the same decision. Did you consider just using the new master reservoir without the power boost?
Are the pedal configuration the same? Horton Hotrods ? Milton ? I am really interested in where you pick up the vacuum from. Are your wipers electric or vacuum?
I hope your conversion works well.
Regards

dcneric · Poncho Master!

Having messed with a couple hotrods over the years I've only run non-power under the floor. Your set up looks very well done. With the new system, you should have residual pressure valves in the brake lines going to the front and rear and of course a proportioning valve for drum/disc configuration. The vette master cylinder just has two equal reservoirs unlike a drum/disc which has a large and small reservoir.

To draw vacuum I would take from the intake manifold and don't forget the check valve at the brake booster so you don't loose vacuum.

Best of success!

rabbit64cs · Canadian Poncho Superstar!

Pretty much the same set up I used on my 51 .

68 corvette mc I believe was 1" bore . External 15 psi residual for rear drums and 2 psi residual for front disc. And a dual 7" booster.

Run a hard line for your vacuum , and like Eric said, put a check valve near the booster.

Being your mc is lower than your wheel cylInners.. Can be a pain to get them to bleed .

dcneric · Poncho Master!

"Being your mc is lower than your wheel cylInners.. Can be a pain to get them to bleed . "

Vacuum pump, should work.

4SPEED427 · A Poncho Legend!

I have used a suction gun to bleed brakes by myself. I would hope it will still work for this setup too.

rabbit64cs · Canadian Poncho Superstar!

I used a vacuum pump .. Was still painful, but helped . A pressure bleed would be ideal .. But that's not a hobbyists tool .

Turdmagnet · Veteran Member

I've got the proportioning valve and residual valves in line but you can't see them in the photos. And the m/c is for a disk/drum setup - does have 2 different sized reservoirs. Paul at Hortons was very helpful in making sure I had everything I needed.

For the vacuum I'm going to tee off the 1/4" line going to the wipers - the only other port on the intake is an 1/8"npt so I'll go with the larger. Thanks for the input on the check valve !!!

I didn't have much of a problem bleeding them when I first did my dual system - hope things are the same - that's tomorrow's night task - wish me luck

Turdmagnet · Veteran Member

silver steak wrote:
Very nice set up. I am nearly at the point where I have to make the same decision. Did you consider just using the new master reservoir without the power boost?
Are the pedal configuration the same? Horton Hotrods ? Milton ? I am really interested in where you pick up the vacuum from. Are your wipers electric or vacuum?
I hope your conversion works well.
Regards

Hey Dale

I tried to be cheap and make the drum/drum master work originally, but when it didn't and I needed to replace it as well I decided to go the booster route. There's only about a 4.5:1 advantage on the stock pedals - everything I read said you should be around 6:1. The mount I made keeps everything in the original location/configuration - even reused the same locking system the original setup had. Hortons is in Milton Ontario - just west of Toronto.