Settle a brake argument

[69hurstolds]

AHA!!!!!!!!!!!!!!!!!!!!!!!!! FOUND IT. HIDING IN PLAIN SIGHT. Just had to get the right book. We can put this puppy to bed.

18003752 is the manual master cylinder for 78. 18005266 for 1979 master cylinder. Interestingly, these are nose-up styles. As I suspected, there was a separate part number brake pedal because the power brake pedal had only one pin on it.

18002438 is for the rod/boot for the m/c, 78/79

1262963 (upper) and 1262964 (lower) for the "cover" aka "adapter plate" for the master cylinder hole. Interestingly, fits 78-80 Buick Regal too. But in 1980 they went with metric bolts. Oldsmobile listings have 78-79 but no 1980. The adapter plates were discontinued from GM in 1990.

Also, found some other info about the brake pedal for manual setup.

Manual brake pedal part # 1256194 has the same size
(small) padas the clutch pedal. I have seen pedals
with the brake rod attachment pin in the upper
(Manual Brakes), lower (Power Brakes) and both
holes. This pedal is identical to part # 1256193
automatic transmission pedal except for the pad size.

 

[69hurstolds]

The 78/79 manual master cylinder has an updated number- 18030353 if you need it.

The 79 manual master cylinder 18005266 says its compatible with the following numbers below, according to Dorman, whose p/n is M39166.

And interesting aspect of these numbers is that it shows ACDelco 18M111, which is the alternate for GM p/n 1803:0353 above. So it appears 78/79 is the same now in consideration of the master cylinders.

• General Motors 18004204
• General Motors 18004263
• General Motors 18005266
• General Motors 18005274
• General Motors 18005275
• General Motors 18010276
• General Motors 18001001
• General Motors
• A1 Cardone 10-1737
• A1 Cardone 10-1741
• Raybestos Brakes 101252
• Bendix 11737
• Centric Parts 130.62005
• Centric Parts 130.62095
• ACDelco 18M111
• ACDelco 18M79
• ARI 83-36005
• ARI 83-36095
• ARI 83-50005
• Wagner Brake F101252
• Wagner Brake F101256
• Autospecialty M-82005
• Autospecialty M-82095
• Fenco M1737
• Fenco M1741
• Aimco M900240
• Aimco M900302
• Wagner Brake MC101252
• Coni-Seal MC101256
• Wagner Brake MC101256
• Raybestos Brakes MC39027
• Raybestos Brakes MC39166
• Coni-Seal MC510480
• Fenco NM1737
• Fenco NM1741

 

[pontiacgp]

your last two posts should be a stickified

 

[Kra5379]

My 2 cents here is, when you boil the questions down to their simplest form, yes brake boosters do affect pedal travel, stiffness and feel....but do not always increase pedal travel or male the pedal feel softer. Take a vehicle that uses a "hydraboost" style booster (it uses hydraulic pressure from the power steering system for it's source of "assist" and I've driven hydraboost vehicles that were just a bit low on power steering fluid and have been able to feel the pedal react in sync with the sounds and state of of the steering iin any particular moment. As opposed to a vacuum booster which uses engine vacuum to provide assist and almost universally makes the pedal feel softer or "spongy" and it does affect the amount of travel, to test yourself, simply leave the engine off and pump the brake pedal 10-15 times and visually look at the height it rests at afterwards.....likely it will be higher than the gas pedal, then start the engine and hit the brakes and instantly it will drop noticeably lower. As far as adjusting drum brakes for improved pedal feel, it depends on the specific vehicle. Ive had identical models and years of vehicles that come in with really spongy pedals and a few clickks of the adjuster brings it back up on some, others no change. Not like the days of "duo-servo" style braking systems (4 wheel drum) where just a tiny over or under adjustment of one wheel compared to another or all the others caused all types of weird symptoms and behaviors from cars.