Master cylinder leaks from behind after fluid change

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IstoT

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Howdy,

I had my car on fluid change one month a go where they changed brake fluids witch were very old (in my knowledge it was DOT 5.1). There was some moisture over the booster and it was rusty all ready but I didn't notice any leak back then. Now I have notice that master cylinder is leaking between master cylinder and booster.

I found some thread where it was mention that if use DOT 5.1 break fluid this could cause the leak. Is that true and is it better flush brakes with DOT 4 before even try to buy new master cylinder? Or any other idea to get rid of this leak.

 
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Found finally information of right master cylinder..this is right one.

CARDONE 10-1378 Remanufactured; With Reservoir Info

Front Disc brakes; Rear Drum brakes; Power brakes; without Bendix Casting

Also this could be use able

CARDONE 13-1378 Remanufactured; With Reservoir

 
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Here is link to National Parts Depot NPD website with correct PDB cylinder. The piston diameter for PDB is 15/16 of an inch the manual brake has a 1.0 inch diameter piston.

Your current cylinder probably has rust in it that made the rubber piston leak. You should not use the new type brake fluid in the system.

You should flush the whole system out when you change it. Keep the original you can order a rebuild kit and hone the cylinder if not too bad.

You might want to go ahead and get new rear brake cylinders and kits for the front calipers when you order the master cylinder. If one has rust they probably all do.

https://www.npdlink.com/product/master-cylinder-assy-correct-style/103669?backurl=search%2Fproducts%3Fsearch_terms%3Dpower%252Bbrake%252Bmaster%252Bcylinder%26top_parent%3D200001%26year%3D1971&year=1971

I think NPD will ship world wide.

Cheers,

 
Thx advice..that master cylinder looks exactly same as is mine. Gladly all bolts opened normaly..:).

One more question pop on my mind after I looked more carefully of my booster....there is text Bendix 950. Does this change what master cylinder I need to choose or is it same which I choose..just take care that it is for front disc, rear drum and booster compatible?

Example if there is text "Application Notes:Will not fit models with Bendix casting."..does it block this particular master cylinder from what I can choose?

Model: Cardone 10-1378

Universal:

No

Make:FORD

Model:MUSTANG

Submodel:MACH I

Beginning Year:1970

Ending Year:1972

Engine Type:V8

Engine Size:5.8L/351

Engine Family:Ford Cleveland

Front Brake Type (application):Disc

Rear Brake Type (application):Drum

Application Notes:Will not fit models with Bendix casting.







temporary image hosting

 
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Ok..thx...it's weird that there is mention about that Bendix Casting incompatibility... :chin:

 
I found pdf where is all Cardon master cylinders and numbers and what number is same as other.

Cardon Master Cylinder IDGuide

From that pdf I found that 10-1378 and 13-1378 are same...later one is just replacement for first one.

 
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