Hello all. I am a Buick guy in need of some information from the Olds community. For the past few weeks I have searched every corner of the Internet looking for an answer about the correct, original master cylinder used on a 1968 Buick GS400. I'm trying to do a manual drum to power disc conversion, but I want to use all factory correct parts. According to GM Master Parts catalogs, some 1968 Oldsmobile used the SAME master cylinder. PART # 5468774, Stamped "DW".

So far, I have been unable to locate this MC. Does anyone know what the correct MC casting number is for a 1968 with power (4 piston) disc brakes? At least with the CASTING number I'd have a better starting point for further searches. Does anyone know if a reproduction is offered for Olds? There are no online listings for Buick. Does anyone know of one for sale (any condition)? Any pictures of a factory correct 1968 disc brake master cylinder are appreciated. Thank you all.

PS: I used to own a 1971 Olds Cutlass SX with 455. Never should have sold it.

 

My reference shows the same number you listed. Then I've got a setup from a 1968 442 that had 4 piston calipers on it. I can't say for sure this is original to the car, but it does have the bleeders on it so its an earlier one. The number cast into it is 5460346 so others will have to chime in if they believe its the original number and the one you need or not. Here's a few pictures of it.

 

I don't know if this has the correct casting numbers on it. But first glance it looks correct and the listing does say it fits the Buick too. John


http://www.fusickautomotiveproducts....p?number=679MC

 

Does it have any letter code stamped on front pad? The "DW" code would verify originality and usage.. Thanks for the pictures!

 

The one in the photos doesn't have any stamp on it. But I do have one that has the same casting number and does have a stamp. The W is real clear, I was thinking the first letter was an O but it could be a D. I'll try to clean it up and get a better view of it tomorrow. John

 

Here is some info about that m/c you are inquiring about. One of the guys who replied to it said he might have one.

https://classicoldsmobile.com/forums...-cylinder.html

 

Thanks for the link. Good thread that confirms the "DW" code as 1968, but still no definitive answer on casting number. I sent the a PM to the guy that mentioned having one, but it's from 2013. Fingers crossed.

 

Sorry, its not for sale as I need it for a project car. But here's confirmation of a DW stamp on a mastery cylinder with the casting number of 5460346. Attached are photos of the part. John

 

FINALLY! Confirmation. You are the man! If you ever change you mind or come across another, please keep me in mind. It seems the "DW" are more plentiful in the Olds world. Disc brakes were only ordered on 4% of Buicks in 1968. Thanks again!

 

I can confirm my original DW master matches the casting number posted above as well.

2blu442, that original MC lid is in amazing condition!! Really hard to find them that nice.

 

Hi Luke
Yes, some cars that have spent their life here in Southern or Eastern Oregon have survived quite well! I've also found parts cars in very Northern California (North of Redding) that have really nice metal on them. There's just a little of the rainbow color that I think was originally anodizing on the booster as well. John