Brakes - Is this a good plan?

Discussion in '1947-1954' started by FarmTruck, Mar 17, 2010.

  1. FarmTruck

    FarmTruck Member

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    OK, I know that brakes are a good idea, but is this a good upgrade plan?

    Here's the situation:
    The '51 that my son and I are rebuilding (but have never driven) has the original master cylinder. I'm unemployed, so money is a bit of an issue. I used to own an Austin Healey, so I live my life thinking that something major on a car is going to fail at any moment.

    Here's the current plan:
    Install a dual-cylinder, non-power master cylinder
    Start with drum brakes.
    When the kid gets enough money, upgrade to disc brakes (still manual) if he wants more stopping power / better fade resistance.
    If he still needs more stopping power, install a booster on the MC.

    Questions/Concerns:
    If a buy a MC set up for disc/drum, can I simply remove the proportioning valve for use on a drum/drum setup?

    Should I just make the jump to power brakes to begin with? My concern is having the motor quit, leaving my son with no vacuum boost and a pedal he can't push down.

    Should I cut to the chase and pony up for the full power/disc setup?

    Any advice would be appreciated.

    Harry
     
  2. bigtimjamestown

    bigtimjamestown Member

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    I've had really good luck with a mid 70's GM 3/4 ton truck master. They have a bigger bore in them but the overall size is about the same. I've used this on front wheel disk brake setups and four wheel disk brake setups and the stopping power without the booster is very good. You don't need a proportioning valve for 4 wheel drum brakes. The only modification that had to be made to the master was to drill into the indentation in the piston about 3/8-1/2 of an inch so the push rod from the brake pedal doesn't fall out. Some are already drilled and some aren't. I think it;s the difference between power and non power brakes. You can modify your original mounting bracket to except the new master and make a push rod out of 3/8" round stock and use a aircraft rod end to bolt it to the pedal. It's actually very simple to do and if you know how to cut and weld you can do it for under a hundred bucks. I hope this helps...Big Tim :cool:
     
  3. Flashlight

    Flashlight Member

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    My 2 cents worth...

    I have been happy with the drum/drum power booster setup I installed in my 47'. It is a stock 216, so I don't drive fast by any stretch. It has a nice modern feel to it and it really helps in a forced stop. I bought it from our sponser, but I see them on Ebay for $169. It has the dual cylinder you wanted for safety.

    I put it on in a morning with a little extra brake line work. Having said that...the old drum systems still do not stop as fast as modern disc brakes. Don't ask me how I know. We all grew up with drum brakes and can judge stopping distance. Your son has not. We all did crazy stuff and by God's grace are here. We all know some who are not.

    Stopping is still more important then going in my book.

    Flashlight
     
  4. mel 55_1

    mel 55_1 Member

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    After two significant occasions when I found myself in the position of pushing on the brake as hard as I could and still not being able to push hard enough I too decided it was time for an upgrade. And, with the same start simple and move up plan like yours.

    I've got as far as the dual-cylinder, non-power master cylinder with the original drum brakes. It works so well I'm not planning to do anything else. I guess, of course, it depends on how fast you expect to go in the thing, but as I rarely get above 60 I feel very comfortable.

    I bought the parts from CP and they were an easy fit. 71-919P gives you a new dual master and the remote filler, and 71-984 gives you the mounting bracket, the fittings and a new push rod from the brake pedal. It's then just a case of running new lines - mine are one circuit front and one back but I know some run diagonal circuits. As I remember the lines between the remote filler and maser cylinder that came with the kit were not good and I ended up getting some myself. I didn't upgrade anything at the brake end but have replaced most all of the bits there with original matches.

    Sorry about the Austin Healey ... but you know why the English drink warm beer, our fridges are made by Austin.
     
  5. vwnate1

    vwnate1 Member

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    Thread hijack !

    " A Gentleman has no business motoring about after dark " ~ Joseph P. Lucs

    LUCAS : inventer of the intermittant windshield wiper ! .

    The LUCAS three position switch : dim , flicker & off .

    :p
     
  6. FarmTruck

    FarmTruck Member

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    Thanks, Everyone!

    Thanks, Big Tim, Flashlight, Mel, and even Nate!

    I appreciate the advice and the Lucas comments. Thanks for including the part numbers, Mel, that really helps a lot.

    Big Tim, I checked the online prices of a mid-70's GMC MC - they're dirt cheap! I might even be able to find one even cheaper in town. I've got the cutting part figured out, just learning how to weld. Could be a really good option, too.

    Anyone who's ever driven British cars knows that Lucas is the Prince of Darkness ...

    Harry
     
  7. bigtimjamestown

    bigtimjamestown Member

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    If you modify the original mounting bracket just make sure you use thick plate like1/4" and you put in a corner gusset so that nothing flex's when you step on that brake pedal. For a push rod you can also use a long 3/8" grade 8 bolt and just cut the head off and round the end. Just a couple tips, I hope this helps.....Big Tim :cool:
     
  8. coilover

    coilover Member

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    If you stay with manual brakes be sure to use a m/c with the same size bore or slightly smaller. A larger bore will give a higher pedal but need much more leg pressure to stop. A smaller bore with a 10# residual pressure valve will give lower pedal but less effort to stop. We're talking 1/16" or so, nothing radical. I have had very good luck with the power drum set up but use discs for one pulling a trailer, hilly use, or deep water situation. Stopping is directly related to the amount of friction material in contact with the cast iron on a drum or disc plus the pressure applied. Drum shoes have way more area than disc pads so with equal pressure drum brakes will stop better ONE TIME. Heat makes drums grow AWAY from the shoes while while a hot rotor grows TOWARDS the pads plus, the pads act as wipers to clean the rotor surface before any contaminate (like water) can get between the pad and rotor. For normal use and less cost the drums would work fine. Very glad to see your concern about brakes first for a beginning driver so I'm sure you will also closely inspect the steering and handling since it can help avoid something that just brakes might not.
     
  9. FarmTruck

    FarmTruck Member

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    Thanks, Again!

    Big Tim and Evan -

    Thanks for the great advice. I don't trust my welding skills yet, so if a buddy of mine can't fabricate a bracket for me I'll pony up and buy one from our sponsor. Brakes are definitely not the place to cut corners!

    Since we live in a dry climate I think that drums should do the trick. Repeated hard stops in wet weather always got scary in the Austin Healey. That car had THE WORST brake/clutch design ever. Both systems shared one small mc reservoir. The clutch slave blew out, and when I pumped it it drained the fluid, causing me to lose the brakes. That's when I learned the importance of stopping!

    Harry
     

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