Hi all. I have a 71 Satellite with power disc/drum combo. Is there a more modern master cylinder that is a bolt in replacement for what I have? Original looks is of no concern. Aluminum and plastic would be just fine. I'm just tired of the leaky masters. The remans that I have used all leak from the get go and get worse over time. Anyone know an application that I can ask for at the part store that will bolt up and go?

Thanks in advance
roe

The modern aluminum/plastic masters are usually 2 bolt. Dr Diff has the adapter plate and matching master you need.


http://www.doctordiff.com/

the 2 bolt will possibly have a different flange thickness and piston depth difference plus there is for sure the adapter plate addition thickness so I would order the MP or other brand adjustable pushrod to restore the pedal height. I had good luck with a parts house 1&1/8 alum/plastic rebuilt 2 bolt truck MC

I had this same question and measured the difference last week. The two masters that were tested were...68 Dart 4-wheel drum brake(non power assist)and an aluminum 2 bolt 1 1/32" bore. The back of the piston in the 68 master is a lot deeper then the aluminum master. When the adapter is bolted on, the depths match each other. The stock manual pushrod will work with the aluminum/adapter combo. I highly doubt this is a coincidence. I'm sure the adapter thickness was designed specifically so the pushrod length remained the same.

Thanks guys. I've bought a few items from drdiff recently. Don't know why I didn't think to check with him. I call him later on.

if the iron flange thickness/piston depth is the same for all of em & same for the alum 2 bolt MC family then it was a good plan to make the adapter thickness just right to maintain original pedal height

Quit buying remans?

Rockauto lists a NEW Raybestos MC for your application, MC36307, for $37.00.

if you have power brakes already and want to keep them, you can get a late model power booster from either a 79 dodge magnum or a Cordoba and that will have the same firewall mount as the 71-74 power booster, but will also have a direct mount for a 2 bolt master cylinder. this will work on ebodys as well. then any 2 bolt master will fit the car, I usually get one from a truck with a plastic reservoir. no more leaks and the stopping power is great.

If I go this route will the brake lines bolt up or do they need to be changed? Also what about the pushrod? Or does it come as a loaded booster and mastercylinder pair?

I ponied up the few extra bucks for a new one from the parts house and it lasted longer but leaked too. Don't remember the brand but I think it was duralast.

Duralast...

I don't buy parts from Autozone for a reason, it's generally crap.

If I have time it's RockAuto.

If I need it sooner, it's NAPA. If it's used oil I need to dump then it's Autozone.

Haha. Ok. I'll probably give them a shot then.

if you have a power booster already, then you should have the correct linkage on the pedals. the master cylinder and booster match because they are made to work that way. you need the correct linkage on your pedals to make the late model booster swap work. i'm pretty sure all I had to was move the lines slightly to make them mate up to the new master. really was a piece of cake. I unfortunately sold the car, and this time i'm going hydroboost

The adjustable pushrod is for manual brakes, the OP has power brakes and the pushrod on the front of the booster usually won't adjust out far enough to compensate for the adapter thickness. Fabrication time.

I don't know if a '71 would be different but, what I did on my wagon was swap the '73 booster for a '79 (Cordoba) unit to get the two bolt mount for the later aluminum master cylinder.

The master cylinder was off an '82(?) Gran Fury (M-body).

I had to tweek the brake lines a little to get them to line up, but, the fittings themselves stayed the same and worked fine.

If I remember correctly, the only difference was at the pedal. The diameter of the hole on the pushrod was bigger (or was it smaller? Its been too long). I don't remember if I swapped pushrods or the pivot bolt.

It was pretty easy and straight forward.

The newer pushrods have a smaller diameter hole. I installed a plastic bushing in an adjustable pushrod to make it work on an 82 Cordoba.

So originally I ASSumed that these were like other parts where a couple of manufacturers supplied everyone else. Now I know thats not the case.

That still said, I think I'm still going to do the swap to later booster with 2 bolt MC and plastic reservoir. Since my linkage is already good as I have power brakes already I should be good to go. I also believe I have an adjustable pushrod already. If not I can order one.

I missed that you were dealing with PB. if you dont have the adj pushrod, do not order one as it is a manual brake item

The depth of the original master cylinder piston to the mounting flange is the same as the aluminum master/adapter combo. It should bolt right on to your existing booster. Measure it yourself and find out.

Even better.

Ordered from the doc