How do you tell if a booster is not useable............

[bandit67]

Hi Guys, pulled the brake booster off of my 72 to clean up the firewall. The car has been sitting for the last 15 years and has the original booster. Bought a rebuilt one from the local auto parts place. The rebuilt unit will fit and but is much different than the original.  I like to original when possible. Other than the diaphragm having a hole in it , how can you tell when a booster HAS to be replaced. The rebuilt unit will hold vacuum for a bit longer than my original.  What is required........a booster hold a vacuum........or holds so much for so long..........thanks.........John B

[Nacho-RT74]

No one part of booster is really imposible to repair and in fact they are a piece of cake job. For a while housing is in good conditions what mostly of then only could get some surface rust, everything is easy to replace/repair. they consist on just rubber parts, seals etc...

If is posible down here in Venezuela, then also up there, althought a good quality vacuum valve is becoming hard to find here. Aftermarket replacements valves available here breaks and melts easily with heat. I had luck that I found a Original NOS one about 2 years ago, and also got a used one in perfect conditions to have spare. The original what came on my car got damage after 30 years

With diaphragm instalation on center plate exception, rest of rebuilt job can be done by yourself.

So IMHO I think you can get your original booster up the ends of times.

[Chryco Psycho]

there are shops  that will rebuild your stock booster

[Chatt69chgr]

The Bendix dual diaphram booster was used on many 69 Chargers.  In fact, I have a used one.  I have never attempted to repair one of these but wondered how you get it apart.  It appears to be crimped together.  Do you clamp it in a vice and rotate the back half?  Assuming it comes apart,  where do you get replacement diaphrams and the bellows seal in the back as well as any other parts needed for a rebuild.  I have not run across rebuild kits for these.  I will say that the Cardone unit listed on rockauto.com for a 69 Charger appears to be identical to the used one I have (least ways, the one listed for front disc/rear drum application). 

[bandit67]

I, also, Chatt, have never seen rebuild parts available. Hemmings lists many folks that do rebuild boosters , so somebody has them for sale. My stock booster is held together by a large band, held together with a quarter inch bolt. The bolt has some flat spots ground into it to keep it from coming loose. Looks like it will have to be cut off to remove.   As to the disassembly of standard boosters , I have never seen the tool to take them apart.  Maybe some members here have...................J