Master cylinder piston hold in tab concerns

[Soflocudaguy]

I Have a 70 cuda manual Drum brake car, I purchased reman MC . Is the small flimsy metal tab With one screw the only thing that holds the piston in ? What applications were the oval plate with 2 bolts used ? I see several old MC'S laying around a buddy's shop and some have the oval plate and some don't. Any Breakdown of when and what should be used is much appreciated.

[pschlosser]

I, too, am curious which models the 2-screw diamond-shaped retaining plate was used.

Keep in mind, the flimsy 1-screw retainer is just fine.  There is very little (if any) force ever pulling on the piston to pull it from the M/C.  The retainer just needs to be strong enough to counter the force of the piston return spring within the unit.

[JH27N0B]

For manual brake applications it's a retainer for the dust boot.
Not used when installed on a power booster.

[pschlosser]

For manual brake applications it's a retainer for the dust boot.
Not used when installed on a power booster.

Good call.  I think it's the same boot, be it on the back of the booster, or back of the master cylinder.  But that retainer may be manual-only drum brake master cylinder.   The dealer parts book  suggests the master cylinder (for front drum brake) was  the same for both manual and power.

[JH27N0B]

The master cylinder was the same either way.  You'd reuse the boot retainer installed on the old master cylinder, along with the pushrod, if you were servicing a manual brake car.
A new rubber pushrod retainer was supplied with new master cylinders to use to install and secure the pushrod in the master cylinders primary piston, which mechanics working on a power brake car would just discard.
They may have even included a new boot?
The rebuild kits had new boots included I'm pretty sure.  I probably have a NOS kit stashed away which I'll have to dig out and look at.

[cuda hunter]

@Soflocudaguy
What brand is your reman? 
Pics? 

[Soflocudaguy]

Dorman m71258. It did not come with anything. I never had an old set up to go by.
I have the correct rod with new rubber grommet. The piston did have the groove inside to hold the rod/grommett in place. I'm just trying to figure out if the Tab is all that really holds the piston in correctly/safely. Dorman shows it for manual Brake and a 1 inch Bore which shows correct for 70 E manual drum set up.

[pschlosser]

Dorman m71258. It did not come with anything. I never had an old set up to go by.
I have the correct rod with new rubber grommet. The piston did have the groove inside to hold the rod/grommett in place. I'm just trying to figure out if the Tab is all that really holds the piston in correctly/safely. Dorman shows it for manual Brake and a 1 inch Bore which shows correct for 70 E manual drum set up.

I have the same problem.  No boot retainer.  I'm hoping when I find a used one, it will come with  the retainer.  "The Ram Man" has used ones for sale at $35 a pop.