I would like to get an aluminum master cylinder for my 67 Dart. I would like to go to my local parts store to get it so if it should ever go bad I can take it back and swap it without having to order a special one from some out of state parts dealers. Plus the aftermarket ones are expensive. I went to get one for a 85 dodge diplomat because they had aluminum ones but the one they had was cast iron. Does anyone know of a factory replacement one that has the 1 1/32" bore.

I copied this from Dr Diff

OEM 2-bolt aluminum master cylinders with plastic reservoir:

'95 Lebaron 7/8" bore**

'89 Dakota 15/16" bore**

'85 Diplomat (F-body) 1 1/32" bore*

'85 D-150 1 1/8" bore*

**Back of piston must be bored to accept manual brake push rod and retainer.

* Back of piston will accept manual brake push rod and retainer.

Rule of thumb:

1. Master cylinder piston size is relative to caliper piston size. Large caliper pistons require large MC piston.

2. All things equal, smaller bore master = higher line pressure and longer, softer pedal stroke.

I think the oe alum started in 79 as a D100 truck app for that yr disc/drum is alum but iirc it is a 1&1/8 bore. I'm surprised that an 85 dippy came up as iron as my 83 cordoba was alum. I'd find one of your parts houses that can look up the bore dia of a 79 up app and most of them are rebuilt & rebuilt M/C's have a very poor reliability (alot of comebacks) whereas one from Doctor Diff here on Moparts or Rick Ehrenberg would be a new unit and there wouldn't be any prob getting the right bore size. From the bore size you have in mind I am assuming manual,fyi just be sure to request (& check if a parts house one)that inside the piston that it has the wide recess for the neoprene retainer to lock into as opposed to a smooth surface like the inside of a "thimble".

I just purchased one from Autozone part #M1822 for $16 plus core and asked for an 85' Diplamat MC, and it is aluminum.

The factory ones were aluminum but a lot of times the rebuilt ones will be cast iron. Ask for a new one at the auto parts store but check the price first. You might be better off just ordering the correct one from Doctor Diff.

I've had good luck ordering late '70's Aspen/Volare with manual disc brakes master cylinders by Cardone. I believe they are 1 1/32". Don't have the part # handy here at work.

Unfortunately, the rebuilt aluminum master cylinders don't usually come with the reservoir.

I have a 15/16" bore master. Does anyone know the specs for boreing it for the push rod?

Thanks...........Ted

Do these alum. MC's actually have a residual pressure valves built in?

no as the disc half next to the firewall cannot have one and the drum half the metal quarter sized reinforecments behind the wheel cyl cups take care of the RPV function but always stick a drill bit deep into the brass cones to check as it is a piece of neoprene on top of a spring and you'll feel the springiness if it has one and if the drum half does have one it's not a prob.