Delco booster date decode

[My68SS]

Hi crew, the power brake booster in my 12C built 68 has 326 stamped into the front of the top lock tab, and 9078 stamped into the rear of the same tab.
Is the 326 a julian date - 326th day of the year? If so, how is the year determined?
Do the numbers look right for my car build date?
TIA

[baldeaglemtnman]

9078 is a 68 Camaro per Jonesy at Team Camaro.   http://www.camaros.net/forums/showthread.php?t=55781
Julian calender 001 = Jan. 1  365 = Dec. 31  1968 was a leap year so 326 would be Nov. 21 if I counted right.
Don't know the lead time on component parts but a month prior seems reasonable for your car.

[Jerry@CHP]

I would say it's the real deal.  This booster SHOULD NOT have the "Delco Morane" stamped on the front cover.  That should confirm it.  Over the years, many have sawpped out the front covers.

Jerry

[1968RSZ28]

Hi Rob -

   I just checked the power brake booster on my 02C Los Angeles built '68 Z/28.  It is also stamped 9078 on the back of the tab.  My julian date stamp on the front of this tab is 343.  When I count to 343 on a 1967 calendar I come up with December 9, 1967 which is a  Saturday!  

Jerry -
 
   Have you seen a Saturday date on these brake boosters before?

Paul  

[Jerry@CHP]

Yes, I have.  When I interviewed many of the Norwood plant workers who were transfered to Baltimore, I had asked them about that.  During that time period, I was told that there was no shortage of overtime for the plant workers.  Maybe John Z can jump in and tell us more?

Jerry

[My68SS]

I would say it's the real deal.  This booster SHOULD NOT have the "Delco Morane" stamped on the front cover.  That should confirm it.  Over the years, many have sawpped out the front covers.

Jerry

You are so on the money Jerry!      That is exactly the case, no 'delco moraine' stamp anywhere.
Your comment has precisely answered my next question regarding that stamping, as I know for almost certainty that this is the original booster to the car.

As for determining the year, is 9078 just a sequence number that is known to represent 1968?
What would the numbers be for 1967 and 1969?

Many thanks everyone for their input 

[1968RSZ28]

Yes, I have.  When I interviewed many of the Norwood plant workers who were transfered to Baltimore, I had asked them about that.  During that time period, I was told that there was no shortage of overtime for the plant workers.  Maybe John Z can jump in and tell us more?

Jerry

Jerry -

   Thanks again!  Once again, your expertise has cured my anxiety.  

Paul

[My68SS]

After some more thought, given my car was built late 67, the 9078 number must represent the 'model' year 1968 ?

[1968RSZ28]

Rob -

   I will quote from Jerry's book in an attempt to help:  "all 1967 and early 1968 Z/28 power brake boosters were stamped 8515.  Mid and late production 1968 Z/28 power brake boosters were stamped 9078."  I'd recommend both of his books even if you don't have a Z/28.  Here's the link:

http://www.z28camaro.com/index.html

Paul    

[My68SS]

Thanks Paul, I guess late Dec 67 has to qualify as 'mid' 68 model production, though it is only about 1/3 the way through the 68 model year.
Mine must have been amongst the first to get the 9078 number?

[Jerry@CHP]

1969's use a 9204, and there are two different size number characters that were used in 1969.  The early '69's use a large 1/4" stamp while the later boosters after Jan-Feb 1969 use a smaller 1/8" stamped number.

Jerry

[JohnZ]

The 9078 and 9204 are derivatives of the Delco-Moraine part number for the booster assembly, although the "tab number" isn't always the same as the last four digits of the Delco part number; the 3-digit number is a Julian date.

Saturday overtime was very common in the assembly plants as well as in the component supplier plants.

[My68SS]

Hi crew, my first post back here after a long......[long]absence. Talk about suffering withdrawal symptoms!!
Anyway, I have much to report on, but I won't unload here, I doubt that I would live long enough to tell all in any event!  I will filter relevant bits out as time goes by.
My baby finally has my undivided attention and I'm going over all her bits, documenting and taking pics as I go and first port of call are her brakes. IMO, effective deceleration is far more important than acceleration, in fact I have a rule of thumb, that a car should be equipped with such tyres, suspension and brakes that it can decelerate about twice as fast as it can accelerate.
Sorry to pick on this old dusty thread, but whilst searching booster specs and numbers, I found that I had started this thread on exactly this topic, so it gave me the answers I was looking for and I thought I would dust it off a little and add some pics of my stamps of the 326 numbers and 9078 numbers.
Cheers, best wishes to all, back with more soon 

[ko-lek-tor]

Good-day Rob,
A great welcome back! Looks like you are proficient in taking good pictures. Keep 'em coming.

[My68SS]

Hi James, thanks for the welcome back into the 1st gen fold and for your comment regarding pictures. Yes, I have been a keen photographer all my life including underwater photography when I was teaching scuba diving [USA PADI system] and also developing and printing my own black and white photo's at school [the school had it's own darkroom], so I will keep them rolling 
Just one question for now, I've noticed various rebuild kits for these boosters, just wondering if you or anyone has any recommendations - cost is irrelevant. Also if anyone knows of any tools or techniques to getting the two halves safely apart? I need to carefully open, photograph everything as I remove the bits and get the two shell halves gold dichromated again.
Cheers,
Rob

[69Z28-RS]

Rob,

I was planning to do my own also, but had insufficient information and had never seen one apart...  I called Steve Gregori at Brake Boosters, Inc  (http://www.brakeboosters.com/) and he told me the process he goes thru... after that call I decided to let Steve do mine, and he did a great job at a very reasonable price IMO.   I'd bet if you called him, he would share with you any information you required after reading the available information in the Chassis Overhaul Manual.

PS.  Overhaul of the Power Brake Cylinder (Booster) is addressed in Section 5 of the 1969 Chassis Overhaul Manual (ST 131-69).

[My68SS]

Hi Gary, thanks for dropping in here  Yes, no doubt you've got experts In the US, but here in Australia it can be a challenge separating Mechanics from Muppets. There are good ones around and I always tell people "You find a good mechanic and stick with them!!"
I'll do some more research on the topic and study up on the overhaul section you mentioned, I guess at this stage I'm more interested in who does the best overhaul kit, regardless of cost.
Cheers,
Rob

[69Z28-RS]

Rob,... there are muppets masquerading as mechanics everywhere I think... 

[My68SS]

Rob,... there are muppets masquerading as mechanics everywhere I think... 

Hahaha rofl!!  Great comment, I'm still trying to get my eyes dry after reading it!! 
Oh dear, even the fabulous US has a muppet problem!
I've got more to say on muppets and headless chooks, but I post that in the general board as it's not particularly Camaro related, besides, I really have to go and dry my face!! 

[My68SS]

Rob,... there are muppets masquerading as mechanics everywhere I think... 

Ok, that is no doubt the case, but I guarantee you that Aussie muppets are faster than US muppets at screwing up the most mundane tasks!!
This prehistoric country I live in is full of cavemen and Neanderthals and that's being unkind to Neanderthal man who was actually quite a clever lad for his time.
Got some interesting pics that show how this country seems to be becoming more prehistoric!! but I'll save all that for another board along with headless chooks!!
But back on topic, I've been looking at the kit from Ricks, though I might get this one apart first, then get the shell redone in gold dichromate, then check out a mob here [hitech brake and clutch] and see if they can get the bits [they had all the cups and seals for the master cylinder] plus they seem to be anything but muppets, more lovers of petrol fumes and internal combustion!
Back soon with some more prehistoric muppet stories! 
Cheers,
Rob

[ZLP955]

Rob you're being unfair towards our Aussie tradesmen. Sure, many are more familiar with working on domestic or Japanese brands, but there are plenty who know American cars inside out, and do good work.
However, in the case of brake boosters, I agree with Gary's recommendation - sent mine to Steve Gregori and couldn't be happier with his work - best in the business IMHO.

[My68SS]

Hi Tim, I hear ya mate and in no way do I want to come across as disingenuous towards all mechanics as you are quite right in saying that there are many who are at the top of the game, which is what I meant in an earlier post when I said that it can be a challenge separating muppets from mechanics and I can tell you, that I have suffered utter misery at the hands of some engineering shops.
On the plus side, if I may sing the praises of a couple of places in my local area, look no further than Performance Modifications in Osborne Park for all your machining work, a bunch of lads who truly know their stuff and always set the excellence bar to a new height and Veem Engineering for all your balancing needs, you will not find better!
Cheers, back soon,
Rob

[My68SS]

Hi Gary, I found exactly that manual you mentioned "1969 Chassis Overhaul Manual (ST 131-69)." Though not on this site, is it on crg somewhere? I found the pdf on camaroowners.com and yes, lots of good info! I've got some bedtime stories to read! 
Cheers,
Rob

[69Z28-RS]

Rob,

I don't know if the chassis overhaul manual is available 'digitally' or not.   I have hardcopy manuals (for SM, OH, and Fisher Body) for my Camaro that I bought after purchase of my car in 1976...

[My68SS]

Hi Gary, here's a link to were I found it
http://www.camaroowners.com/1969%20CHEVROLET%20CHASSIS%20OVERHAUL.pdf
I didn't include this link previously as it is to another site which may be outside protocol for crg and camaroowners.
Will glady let admins here decide if it's ok or not.
Found it's best to right mouse on the link and use 'save target as' method to get the file.
Cheers,
Rob