Topic: brake fluid at rear of master cylinder

[kcodecoupe]

is it common to see damp or light fluid seepage from the rear piston on 67-70 a power brake master cylinder when its removed from the vehicle, master was working normal,

[CharlesTurner]

I wouldn't consider it normal, would be rebuilding or replacing the master cylinder if I saw that.

[Bob Gaines]

is it common to see damp or light fluid seepage from the rear piston on 67-70 a power brake master cylinder when its removed from the vehicle, master was working normal,

Normal to see if master needs to be rebuilt. Do not waste any more time considering any other option . It needs to be rebuilt.

[Smokey 15]

 The old single master in my '62 LeSabre worked well. I pulled it to do a dual master upgrade and found it to be wet. I'd replace yours.

[kcodecoupe]

I feel the same way it should be replaced , i have gone through most of the local parts suppliers trying to get the correct reman looking bendix casting master cylinder for a 70 power disc car, so far no luck.

[67gtasanjose]

I feel the same way it should be replaced , i have gone through most of the local parts suppliers trying to get the correct reman looking bendix casting master cylinder for a 70 power disc car, so far no luck.

IMO, DO NOT EXCHANGE THIS unless yours is NOT the original or in an extreme case, yours is determined as NOT rebuildable. They sell rebuid kits and with a small cylinder hone that can be run on your cordless drill, you can rebuild the original for about the same cost and NOT exchange off a date correct item from an antique vehicle.

If you do exchange it, at least pay the core charge and keep the original, drain it, tag it as a core and put it into the box the replacement arrived in and shelf it for a later date. Too many items are "exchanged" only later to need to get a date correct part or a need to answer a question about authenticity/correctness. I wish I kept more items such as this, back in the day I traded them off for the "easy, cheaper" way 

[Bob Gaines]

Assemblyline Bendix master cylinders are hard to find and expensive to buy if you need to replace one. A easy way to get a reasonable indication if it has been replaced or at least has the correct type is to feel on the bottom side in the middle there is a raised area with a stop bolt for the piston. 67 style typically has a bolt head for the piston stop . Later versions had a cone shaped head typically. The later replacements were refined so they did not need the more primitive stop bolt. Through attrition many of the masters are typically changed to one of the newer versions. There are other characteristics to assemblyline units but the bolt or cone head bolt on the bottom is the easiest to explain.