Okay Lou,
Sorry to ask another question. Just skip it and I'm sure someone else will help me out.

I need to replace the master cylinder on the '73 Duster with manual drum brakes. The one on the car has a large and small resevoir. The one I got from the parts store has same size resevoirs. Which one is correct?

Rob

I think the large and small is for disk brakes.

Same size is for drums.

John

That's what I was thinking. This car had been fiddled with a little. Maybe that's part of the reason the master cylinder doesn't work right. I should probably measure the push rod to make sure that's not wrong. Anyone have the measurements for push rod lengths?

The equal size one should be right, but I'm not absolutely certain. FWIW, I don't think it really matters much. The brake pushrods should be the same for all A-bods too, I'm pretty sure.

I really like the late model Alum MC - saves weight and never rusts.

Lou

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Home of Slant6-powered fun machines since 1988

With the late model MC you have to get a special pushrod and the adapter and a different proportioning valve don't you?

The adapter AREnginnering sells is the correct thickness so the stock push rod can be used. Some adapters are thicker, making the stock PR too short. I don't know if a different combo valve is needed, I would think not. If it's on your drag car, you can use an aftermarket proportioning valve to the rear ($40) and put a line lock in the front. This makes the line lock plumbing a lot easier than trying to use it with the combo valve. I'm going this route with my '68 Valiant racer.

Cecil

I used the same style MC you have (same size reservoirs) in my 63 valiant. This was for a single to duel MC conversion. I was able to use my original pushrod.

I plumbed the rear lines through a Wildwood (Summit) adjustable proportioning valve. It was $40 from Summit.

I haven't tested t he brakes yet, but the install went fairly smoothly.

John

the one with the same size resivours is for drums. a disk cylinder on a drum car might work, but i know first hand that a drum cylinder on a disk car will not work, it holds a significant amount of pressure on the front brakes although they will still turn, but very hard. as i stated in another post, the newer mp style aluminum cylinder is for disk setup and a simple 1/4" thick adapter can be made to use it on our older cars. as far as i know too, all manual pushrods are the same length.

--chad

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74 swinger slant 6, the slowest, most fun car i have ever owned.

A disk MC will work on an all drum car. Every MC I've gotten for my Satellite (10" manual drums) and my late '70 Fury (11" power drums) has been the big/small resevour. I have never had a problem with poor brake performance. If you want to keep the all drum MC, get a rebuild kit. But they are around the same cost as a rebuilt MC. Another tip. When I buy rebuilt MC's, I always take them apart to make sure they are assemeled right. I have seen some with the cups installed backwords, resulting in internal leaking later on.