The casting codes casted into the master cylinder on my '70 442 w/ PDB (JL2) is as follows: "(Delco logo) 5470409 - 1 1/8 (wagon wheel logo) D88".

The casting date code can not be read, to far gone.



The 1970 GM assembly manual and also the 1970 Oldsmobile inspectors guide both state that 442 with power disc brakes should have "5470664".
Is this a assembly number for the whole master cylinder assembly, or should this number be casted into the bottom of the factory original master cylinder???

BTW, My master cylinder does not have the two bleeder screws on the side of the master cylinder.

 

the first thing to remember is that "original" would mean what GM installed on it. many times if the correct part was not availible when the car came down the line the next closest part was used. the line did not stop due to lack of parts no matter what. a buddy of mine worked in R&D at Chevy in the 60's and 70's and told me that more than one SS chevelle was sent to the dealer with 2.76 open 10 bolt rears, etc because the supplier was late. the theory was the dealer could fix it or if no one complained it just got delivered that way.

 

Very true.
My Olds came from the factory with 1 Cutlass cross shaft, and the door panel logos didn't match. One was a Royale base model badge, and the other was from a royale brougham.

 

Lance, the original master cylinder on my Lansing-built '70 442 is also casting number 5470409-1. This is followed by a D2. Don't pay any attention to the "D" numbers; from what I can tell, they designate which mold was used for cast parts (there were multiple molds used for the same casting, especially if that casting was used for many years). The date code should be cast on the bottom as a 1- to 3-digit number.

That raw casting was machined and assembled into several different part numbers. The final part number does not appear on the unit, but a two-character application code should be stamped on the top, front of the casting. I believe you will find a list of these codes in your assembly manual or possibly the Chassis Service Manual. Mine, for example, is stamped "EB".

One other warning: I'm working from memory here, but doesn't the assembly manual show numerous differences in the braking system for cars built in the multi-make GM plants as opposed to the Lansing plant?

 

My '70 Chevelle SS has this machined pad (half moon shaped) at the top of the front with build sheet code "BB" stamped into it. The Chevelle also has two bleeder screws on the side of the master cylinder. The master cylinder has part number 5470409 casted into the bottom of it.

My '70 442 has no machined pad for the build sheet identification code. No side bleeder screws. But it does have 5470409 casted into the bottom. Casting date code is to far gone to read (rust).

The reason I ask is I am going to sent out my original brake boster to be rebuilt and re-plated. I was also going to send out the master cylinder to be re-sleaved and to be rebuilt, but I don't want to spend $200.00 on a non-correct master cylinder.

 

Well, a 1970 with power disc brakes should have the bleeder screws, right? So I'm thinking that your master cylinder is not original. Even if it is original, I guess that if it's missing the application code and the date code is illegible, then there's not much sense in resleeving it, as there's nothing on it to identify it as original.

 

So....my master cylinder for my '70 442 with pdb should be identical to my '70 Chevelle SS with pdb master cylinder, having the machined half moon shaped pad at the front with the code "BB" for 1970 stamped into it, and two fluid bleaders installed into the side???

 

According to the Nov. 72 parts book:
70 F85 power disc, 5471308 first type, with No. 0884 or 1344 on housing tab
70 F85 power disc, 5471636, second type, with 1804
both are Moraine mfg.