Author Topic: 1965 Disc Brake Pedal Differences  (Read 8236 times)

Offline CharlesTurner

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Re: 1965 Disc Brake Pedal Differences
« Reply #15 on: February 07, 2013, 09:41:15 AM »
Like I said earlier my pedals were swapped during the restoration, I know for a fact that the rebuilt pedal set interestingly came from a base 6 cylinder coupe that now reside in my '65 K GT Convertible....

If that's the case, then you have the wrong brake pedal for your car.
Charles Turner - MCA/SAAC Judge
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Offline mustang65ld

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Re: 1965 Disc Brake Pedal Differences
« Reply #16 on: February 07, 2013, 11:01:25 AM »
Thanks all for providing the photos. The reason I brought this to light here is because I am fanatical about getting every detail of my restoration as close as practical to how it would have rolled down the assembly line. These minute differences fascinate me as both an engineer and restoration enthusiast. 
« Last Edit: February 07, 2013, 02:23:07 PM by mustang65ld »

Offline CharlesTurner

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Re: 1965 Disc Brake Pedal Differences
« Reply #17 on: February 07, 2013, 11:36:44 AM »
Thanks all for providing the photos. The reason I brought this to light here is because I am fanatical about getting every detail of my restoration as close as practical to how it would have rolled down the assembly line. This minute differences fascinate me as both an engineer and restoration enthusiast.

Totally agree... and it just goes to show that none of us know everything!  I've been restoring these cars for a long time now and this detail had eluded me.  Ironically, I'm sure I have noticed brake pedals with the 'D', but never gave it a second thought.
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Offline C5ZZKGT

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Re: 1965 Disc Brake Pedal Differences
« Reply #18 on: February 07, 2013, 02:50:29 PM »
I am referring to a post that I saw the HIPO forum:

"Another consideration, which many people are unaware of, is that the brake pedal for a disc brake 65 and 66 Mustang is different than a drum brake version. These pedals sometimes get mixed and although the difference is slight, Ford must have made a different pedal for a reason. The difference is the pin location for the master cylinder push rod. The pin on the disc brake pedal is moved down about the same distance as the thickness of the pin. This give the rod a longer travel in the master cylinder. It would also increase pedal effort which is the down side. The pedals are identified by a "D" stamped into the right hand side of the pedal arm just below the master cylinder push rod pin.

-Fred"

So, If I am reading this right by using a DRUM pedal on a DISC setup I have less pedal effort than a DISC pedal would have?
-Sounds like a neat mod to me!

Offline C5ZZKGT

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Re: 1965 Disc Brake Pedal Differences
« Reply #19 on: February 07, 2013, 09:45:30 PM »
Totally agree... and it just goes to show that none of us know everything!  I've been restoring these cars for a long time now and this detail had eluded me.  Ironically, I'm sure I have noticed brake pedals with the 'D', but never gave it a second thought.

So, Is it possible Charles that you put a drum pedal in a disc car and vise/versa during a restoration?

Offline CharlesTurner

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Re: 1965 Disc Brake Pedal Differences
« Reply #20 on: February 08, 2013, 12:16:14 AM »
So, Is it possible Charles that you put a drum pedal in a disc car and vise/versa during a restoration?

Possible?  I suppose, but it wouldn't have been done intentionally.
Charles Turner - MCA/SAAC Judge
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Offline gjz30075

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Re: 1965 Disc Brake Pedal Differences
« Reply #21 on: February 23, 2014, 05:57:03 PM »
Sorry for churning up an old thread here but my search for a MT disc brake pedal is fruitless and I was wondering if this same difference, as discussed in this thread, applies to auto trans pedals, ie, is the pivot in a different position and is there a 'D' stamped in the arm?   

I would think one could cut down an auto pedal from a disc brake car to get the same pedal as a manual trans car, if they're the same.
Thanks,
Greg Z
Greg Z

Offline C5ZZ

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Re: 1965 Disc Brake Pedal Differences
« Reply #22 on: February 23, 2014, 08:14:39 PM »
Sorry for churning up an old thread here but my search for a MT disc brake pedal is fruitless and I was wondering if this same difference, as discussed in this thread, applies to auto trans pedals, ie, is the pivot in a different position and is there a 'D' stamped in the arm?   

I would think one could cut down an auto pedal from a disc brake car to get the same pedal as a manual trans car, if they're the same.
Thanks,
Greg Z

I would say that both MT and AT cars with disc brakes would have the pin in
the special position, both have the same disc brake master cylinder.
MCA # 00945

65 Fastback, 6 cyl, AT, AC, PS, PB
Rangoon Red/Red Interior

Offline sgl66

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Re: 1965 Disc Brake Pedal Differences
« Reply #23 on: September 04, 2017, 03:17:14 PM »
In honor of Metuchen qwalitee, I present to you a D stamping from my car :P



66 GT 6T09K12---- scheduled Oct 14, bucked Oct 13 '65

Offline jwc66k

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Re: 1965 Disc Brake Pedal Differences
« Reply #24 on: September 04, 2017, 04:37:23 PM »
In honor of Metuchen qwalitee, I present to you a D stamping from my car :P
Earthquakes in Jersey? Who knew -  ;D
Jim
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Offline Bossbill

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Re: 1965 Disc Brake Pedal Differences
« Reply #25 on: September 02, 2023, 02:37:25 PM »
Not sure how I got here many months later, but I'm doing a Hydroboost swap in my 65 modified car and this car came with factory disc brakes. As it turns out my brake pedal might have swapped as it has the drum brake pedal.

But really, his whole topic is about pedal ratio.
Take the center to center distance of the pivot to center of brake pad (in side view) and divide that by the distance from the center of the pivot to the center of the pin.
A non-power car (generally speaking) should have a pedal ratio in the 6:1 area. Power brakes are in the 4-4.5 area.
[Naturally there is a correlation to master cylinder diameter, not discussed here.]

Using the data from my drum brake pedal I get a ratio of approx 6.5:1. Very standard for a non-power car.
If I increase the distance by 0.25 the ratio is now 5.3:1, hence the pedal pressure is higher (if the same master diameter and calipers are used).

Interestingly the 65/6 power brake system uses the same drum brake pedal and the ratio is changed to 4.3 by a ratio changing bellcrank before the booster.

The 67/8 system changes the pedal ratio by mounting the pivot higher in the pedal box and moving the pin appropriately. So yes, the pedals are very different.

In the case of a Hydroboost system on a 65/6 you have to get down to the boosted pedal ratio in the 4.3 area, so you have to move the location of the pin on the pedal even further than either pedal since there is no bellcrank. Not that any concours person would do something like modifying a 65 ;).


Bill
Concours  Actual Ford Build 3/2/67 GT350 01375
Driven      6/6/70 0T02G160xxx Boss 302
Modified   5/18/65 5F09A728xxx 347 Terminator-X 8-Stack
Race        65 2+2 Coupe conversion

Offline kb65

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Re: 1965 Disc Brake Pedal Differences
« Reply #26 on: December 08, 2023, 12:33:40 AM »
So you are saying hydro boost ratio is 4.3:1
ken

Offline kb65

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Re: 1965 Disc Brake Pedal Differences
« Reply #27 on: December 31, 2023, 03:46:31 PM »
The pedal ratios are listed in the 66 shop manual under brakes.
there are 3 ratios listed
manual drum
manual disc
power drum
ken