Question for Frosty

[TWO LANE BLACK TOP]

Frosty...

Just to satisfy my own curiosity...And think you may able to enlighten me..Bonne61 has a thread...Brake Upgrade Advice...and I have a question sort of related to that thread...

GM used two different power brake systems...The Delco-Moraine set up...And the Bendix set up...Both the systems were used simultaneously across all/some the brands for a few years in the early 1960s...So my question is...What determined which cars got the Bendix system as opposed to the cars that got the Delco-Moraine system...Was it determined by which assembly plant the cars came out of...Certain production dates...Certain shifts...Supply pipeline...ETC..???

Any insight that you may have to this question would be appreciated...

Thanks..

TLBT

Edited July 30, 2023 by TWO LANE BLACK TOP

[Frosty]

What an interesting question and topic Two Lane. Thanks for asking.

First some history. Bendix was once partial owned by GM. At one time, GM owned 24% of Bendix. So it was in GM's interest to use their own in-house suppliers to keep costs down.  In 1948, GM sold its interest in Bendix as GM wanted to focus on its expanding automotive operations. Bendix created the first power assisted brake system, called the Bendix Treadle Vac (or BTV for short). This consisted of a brake booster tied to a single master cylinder for a entire drum brake system. This was the very first mass produced power brake system. It was made available sometime in the late 1940s/early 1950s.

BTV was used widely by the auto industry of the 50s and early 60s. The list below is not exhaustive or conclusive but it the longest list I've found thus far. I realize that there are probably more 60s era cars that should go on this list as well but I have yet to find more listings. Estimates range to almost 10 million cars that were built with the BTV system.

Buick 1957
Cadillac 1956 &1958
Chevrolet 1954-58
Edsel 1958-59
Hudson 1954-57
Lincoln 1953-60
Mercedes 1952-62
Mercury 1953-58
Nash 1954-59
Oldsmobile 1953-56 and early 57
Packard 1952-56
Pontiac 1954-58

GM sold it's interest in Bendix in 1948. GM created the Moraine (Ohio) Products Company in 1923 as the manufacturing arm of GM Research operations. At the same time, Boss Kettering's company Dayton Engineering Laboratories Company (DELCO) Products (a,k,a Delco Products) produced brakes for GM. GM consolidated Moraine Products and DELCO brake systems into a single brake division in 1936, calling it Delco Moraine.

While I have yet to find any conclusive evidence of why GM switched from BTV to Delco Brakes, I have two main reasons why I think the change was made over time. Mind you, this is my theory, but I do believe it has merit.

First reason is cost. Bendix was now an outside suppler and Delco Moraine was an internal supplier/division of GM. So supplying brakes made in-house was probably considered cheaper, and patronizing your own corporation vs. a paying competitor for the same part.

Second reason is the cars and technology of the time evolving. BTV was the first commercial power assisted brake systems, but I don't get the impression Bendix did much to highly innovate and maintain it's leadership in the brake product line. Bendix got into other businesses and products like aviation and such. So I suspect they cut themselves too thin to maintain their market lead.

Also automotive technology at that time was changing. Wheel bases were getting steadily longer after WWII, cars got heavier, V8 engines came along replacing low HP flathead 6s and 8s and created the horsepower wars to follow, the mass and speed of cars was increasing thus making for the need for improved braking, and brake boosters moved from under the floor boards to the firewall. Thus Delco Moraine was able to adapt/improve/surpass the once venerable BTV into their own braking system in order to support the changing car market, especially for GM.

Today Bendix is still in the brake business but not so much in the passenger/light trucks. They seem to specialize in large/heavy duty systems. Delco Moraine was consolidated into the Delphi Automotive (now called Aptiv) in 1995, which went bankrupt in 2005, closing 21 of 27 automotive components plants including the former Delco Moraine facilities.

Does that help Two Lane?

[TWO LANE BLACK TOP]

Frosty..

Thank you for the history lesson...Found it very Interesting/Informative...

So from what info that I have been able to gather...I've found that both the Bendix and Delco-Moraine systems were used on Pontiacs until 1965...?? Although the Bendix system used a different style/designed master cylinder in 1965...And was used only on full sized Pontiac cars...

Whereas the Delco-Moraine system was used exclusively on the Tempest/GTO car line from 1965 forward...

As far as I can tell both the Bendix  and the Delco-Moraine systems were used by GM across the line until midyear 1966...?? When all GM Cars started using the Delco-Moraine system exclusively....Starting in 1967 All GM cars used the dual circuit Master Cylinders...

So based on the history/info you provided...plus what I found...It appears that it just depends on which Manufacturing Plant/Supply chain..Luck of the draw...At any given time as to which cars got the Delco-Moraine system as Opposed to the Bendix system during that timeline....

Any other thoughts/comments on this subject would be welcomed...

Thanks..

TLBT

Edited August 5, 2023 by TWO LANE BLACK TOP

[Frosty]

Thanks Two Lane!

Another thing that occurred in the mid-to-late sixties was the introduction of front disc brakes. So I imagine that Bendix system was a drum only solution whereas Delco went to a dual master cylinder and proportioning valve, gradually introducing disc brakes from the smallest to the largest car lines over time.