[Cannonball]

Hi folks,

My master cylinder is leaking profusely from the rear and I was wondering whether the mc/booster combo is correct/original to the car and is worth rebuilding. Everything has been painted black in its previous life. The master cylinder does show the application code EB on the front and has dual bleeders and dual valves. The underside has "5470408" or "5470409" cast on it upside down.
The booster has an upside down DELCO MORAINE stamp. I cannot make anything of the characters on the front of the booster tab, the rear has "042" stamped on it, can't quite make out if there is an additional character after that.
If I am to spend the money and effort to rebuild it, as I understand the booster is plated in zinc dichromate and so is the mc lid. What about the master cylinder itself, some say as cast, some say flat black, would gray zinc phosphate be a suitable finish for it and the valves?

Thanks.

[Dens71TA]

Master cylinder castings were dipped in a semi-gloss black paint bath and then machined. Not uncommon to find some thick paint runs on them. The flat surfaces where the code is stamped and around the brake pipe outlets were left bare metal after the machining process.

[77 Canamman]

EB is correct for '70.

[Transamric]

Originally Posted by Dens71TA

Master cylinder castings were dipped in a semi-gloss black paint bath and then machined. Not uncommon to find some thick paint runs on them. The flat surfaces where the code is stamped and around the brake pipe outlets were left bare metal after the machining process.

X-2!

[RamAirPwr]

Originally Posted by Cannonball

Hi folks,

My master cylinder is leaking profusely from the rear and I was wondering whether the mc/booster combo is correct/original to the car and is worth rebuilding. Everything has been painted black in its previous life. The master cylinder does show the application code EB on the front and has dual bleeders and dual valves. The underside has "5470408" or "5470409" cast on it upside down.
The booster has an upside down DELCO MORAINE stamp. I cannot make anything of the characters on the front of the booster tab, the rear has "042" stamped on it, can't quite make out if there is an additional character after that.
If I am to spend the money and effort to rebuild it, as I understand the booster is plated in zinc dichromate and so is the mc lid. What about the master cylinder itself, some say as cast, some say flat black, would gray zinc phosphate be a suitable finish for it and the valves?

Thanks.

The front of the booster tab is the date of manufacture and the rear is the booster model #...it should read 0426 so you're just missing the last number The tab is small so the stamping often wasn't lined up correctly...dont ask me how I know that
The upside down Delco stamp is also correct so you're good to go