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mt65riv

Dual M/C for '65 w/front discs

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I have searched here and on the web but can't find a definitive answer.  I would rather keep my stock booster as it is fine and use an OE style master cylinder.  I know there are aftermarket units with boosters and prop valves.

 

The Scarebird kit that I got listed all the parts to add the discs to the front of my '65 and that is fine.  Napa had them all no problem.  On the Scarebird instructions they recommend a 71-76 Riviera MC but that has a shallow plunger and the old single unit on my car is about 1 1/2" deep.  I checked with NAPA and the only ones they had for GM in the '70's with Disc/Drum were shallow.  Is it possible to shorten the booster plunger?

 

Anyone do this conversion with stock parts?  Am I stuck getting an aftermarket unit?

 

Thanks!

 

Mike

 

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1967 with disk / drum is a bolt on to your original master cylinder.

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Considering the age of your booster I would go forward by spending the money on the recommended new parts. Consider the $$ cheap insurance, the brakes are not a system to go cheap and roll the dice on.

  Tom

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The recommendations are probably made to keep the entire system "as built" by the manufacturer.  If you're only changing to a dual master cylinder for your drum brakes and your system works good as is, then the switch to the dual reservoir master cylinder from '67 to use on your original booster makes sense.  But if you're going the disk brakes and they require a dual master cylinder, then you should probably do as Tom suggests. 

 

I have a Scarebird kit and a couple of years ago I found an unmolested '76 Riviera and took the entire brake system off of it.  Booster with plunger, master cylinder with lines, rotors, calipers, et al.  When (if) I install the disk brakes, I'll have Booster Dewey rebuid the booster, rebuild the master cylinder and go for new rotors, etc.  I just got all of the parts off the Riv to do a test fit.

 

I just looked at my Scarebird list again and on mine there's no mention of a master cylinder or booster.  I wonder if mine is just that much older.

 

Ed

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Calipers hold more fluid than cylinders. As pads wear, your fluid level will get down to a point you are sucking air.

Of course you can always add fluid, but then if you squeeze your calipers to install fresh pads, you will have too much fluid for the system.

 

Every disc setup I have seen has a much larger reservoir.

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Ed,  All of the boosters listed at NAPA and Rockauto show disc/drum MCs as shallow and drums as deep.  Do you know a part number for a disc/drum MC that is deep?  I can replace the whole thing with a '76 Riviera booster/MC that is disc/drum for about $120.  The OPGI is $330.

 

Thanks.

 

Mike

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To be clear, a '67 drum/drum MC will work on a '65 drum/drum and make it a dual circuit.  There doesn't seem to be a dual MC disc/drum that fits the deep '65 Riviera booster.  The '76 that you got will bolt directly to the '65 firewall and pedals, right?  If so, that is what I will get.

 

Thanks

 

Mike

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OK, so I found a guy that knows of which he speaks...  I got a Raybestos MC #MC39018 that will mount to the stock '65 booster ( it is setup for the long '65 plunger ) and is for front disc/rear drum.  So I can keep my original booster that is working fine and continue with the Sacrebird conversion.  The only other thing besides making my brake lines is a universal proportioning valve ( the dial kind ) on the rear drums so I can dial in the balance.

 

This is the MC I got:  http://www.summitracing.com/parts/agb-mc39018

 

The guy that I got all the information from is Booster Dewey at Power Brake Booster Exchange, 4331 SE 63rd Ave., Portland, OR  97206  503.238.8882.  He knows his stuff and rebuilds stock boosters for anything.  The shop that is behind his house is impressive.  I have a friend who is into older Chevys that has used him for a bunch of boosters.   I would recommend him if you need a stock one rebuilt.  Super nice guy.  Google him and you will be impressed.

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