Joined: Tue Mar 01 2011, 04:53PM
Location: Seattle
Posts: 39
So I have been considering the upgrade to power front discs on my 66 300. I have researched the forum and understand what I need and what I need to do to make this happen.
I know that a disc booster is not required but highly recommended for the swap, which I am in complete agreement with. I also know that for 66, because of the transmission linkage, that I need a narrow diameter booster.
Which leads to the problem of what to use for a booster.
A 66 dual diaphragm booster would be optimum, but considering the near zero availability and $700+ price tag I saw on one, I am concerned this might not be a viable option.
Someone on here previously had mentioned that another model booster from a newer Chrysler or something may work.
Does anyone have any additional information as to what other booster options a 66 300 may have for a front disc swap?
Joined: Wed Aug 11 2010, 10:15AM
Location: E WA
Posts: 1230
GranTorinoSport wrote ...
So I have been considering the upgrade to power front discs on my 66 300. I have researched the forum and understand what I need and what I need to do to make this happen.
I know that a disc booster is not required but highly recommended for the swap, which I am in complete agreement with. I also know that for 66, because of the transmission linkage, that I need a narrow diameter booster.
Which leads to the problem of what to use for a booster.
A 66 dual diaphragm booster would be optimum, but considering the near zero availability and $700+ price tag I saw on one, I am concerned this might not be a viable option.
Someone on here previously had mentioned that another model booster from a newer Chrysler or something may work.
Does anyone have any additional information as to what other booster options a 66 300 may have for a front disc swap?
I would try the swap with your current booster and see how you like it.
Back in 2003 I installed front disc brakes from a 72 Fury into a 66 Newport. The Newport did not have power brakes so I installed the new disc brake master cylinder without any booster. In my opinion the brakes worked just fine and certainly a lot better than the drum brakes. Consistent straight stops without needing to hold the steering wheel. Pedal pressure was high but the car stopped great.
Joined: Tue Mar 01 2011, 04:53PM
Location: Seattle
Posts: 39
All, this is great information. I think I will try the standard booster first. I had it rebuilt professionally a couple years ago, so it is about as good as a standard single diaphragm will get, but may work.
I STRONGLY recommend not using the drum brake booster - yes it will work fine in most situations, but the reality is that it simply does NOT have enough boost to fully energize the disc brakes.
How will you feel when, because you couldn't stop/slow down just that bit more quickly enough to avoid a collision... or worse yet the child that runs out in front of you, that you could have prevented disaster for the sake of a few bucks?
You always find out you don't have enough brakes when you need them the most - when it's too late.
Joined: Tue Mar 01 2011, 04:53PM
Location: Seattle
Posts: 39
Well, for right now I am restoring the front 11x3 brakes (drum thread in the General Tech section). I am also replacing the brake lines (replacements from InLineTube.com with whom I have have several good dealings with in the past on other vehicles).
So, in short, I have some time to find the right booster or a suitable substitute that would work. The car should stop adequately (stress on adequate, not great).
However, the original push behind my question here was that someone in a previous thread from a few years back here had mentioned there were some newer Chrysler replacement dual diaphragm boosters that would work but would not look stock (they were the smaller diameter). I was hoping to see if anyone had that information or if it was just a thought, not something a person had actually done themselves at some point.
My 66 does have column shift and it is the rod based one, not a cable actuated one (which would be so much better, my Gran Torino has that, very nice).
It'll stop well with the 3" brakes and the system up to snuff... just watch out for brake fade on the highway - drums as you probably already know are notorious for having only one good stop in them before they start fading.
The modern small diametre dual diaphragm boosters look like this:
It's still 9.5" wide... keep in mind that the drum booster is 9.25 inches wide, so the 78 disc booster is still a lot closer in size than the single diaphragm disc booster from the 1970 and up cars... I do not know if the booster actually fits or not.
Joined: Wed Aug 11 2010, 10:15AM
Location: E WA
Posts: 1230
jazzandmoparguy wrote ...
I STRONGLY recommend not using the drum brake booster - yes it will work fine in most situations, but the reality is that it simply does NOT have enough boost to fully energize the disc brakes.
How will you feel when, because you couldn't stop/slow down just that bit more quickly enough to avoid a collision... or worse yet the child that runs out in front of you, that you could have prevented disaster for the sake of a few bucks?
You always find out you don't have enough brakes when you need them the most - when it's too late.
Get the right booster.
If I had the choice of front disc brakes set up using the drum brake booster or front drum brakes I would take the disc brakes every time. These cars were designed to work (maybe not great) if the booster had failed. I had a 66 Newport with disc brakes with no booster at all and the pressure to apply the brakes was very similar to the un-boosted drum brakes.
Bad disc brakes are better than good drum brakes.
Usually not enough brakes comes from shortcomings in the brakes themselves and not because the driver has not been able to apply enough force.