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Discussion Starter · #1 ·
I am in the process of converting my 1969 mustang over to power disc brakes. I saw the post today about the difference between the 1969 and 1970 boosters and brake pedals. I have a 69 power brake pedal, but I have a 1970 booster which has the straight push rod, not the one with the curve for a 69. If I went to Autozone and bought a rebuilt 69 booster do they come with a push rod? Also is there and advantage to using either a Bendix or Midland style unit. Thanks for and advise you can offer.
 

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Yes, a new booster will come with the push rod. The '69 one will have a bend in it. The Bendix booster is smaller in diameter than the Midland. If you're using or planning to use a hydraulic clutch, you need to use the Bendix one or it won't fit.

Be forewarned that the booster does not fit in the stock hole for a manual brake car. You have to "relocate" the center hole up about 1", as well as drill out the 2 threaded holes for the manual MC and 3 new holes.

Don't forget the spacer that goes between the booster and firewall. That drove me NUTS for a week, trying to figure out why I couldn't get my brake lights to go off.
 

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Not sure on the condition of your booster, but it would be cheaper to buy a used 69 power brake pedal on ebay and sell your 70 pedal. On my 70s, i didn't have to relocated the center hole that the booster rod goes through. I did have to drill out all the holes for the studs to go through.
 

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How do you know that you have a 69 pedal? According to EVERYTHING I have read, and my own experience converting my 70 to power brakes, the booster and the pedal have to be of the same year. Otherwise, the rod out the back of the booster misaligns with the brake pedal, making it not only difficult to connect the rod to the pedal, but the connection changes the angle of the rod so that stepping on the brake pedal sends the rod through the diaphram of the booster, turning the booster into a very expensive piece of scrap metal. Indeed, I experienced this last bit of misfortune when the seller of my Ford power brake set up for the 70 included a 69 booster instead of a 70 booster, when sending me the 70 spindles, pedal, etc.

I suggested pulling your brake pedal and comparing it with an out of the car 70 brake pedal. You might have a 70 pedal to match the booster in the car.

The midland booster has a band clamp around the diameter in the middle of the booster. The bendix does not have the clamp. The midland boosters are somewhat rare and command a permium price. Even the midland cores are pricey. My experience with the 70 was the same as previously posted here. I did not have to relocate the center hold for the rod.

good luck.
 

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How do you know that you have a 69 pedal?
We need to make a post with the measurements of the 69 and 70 pedals to help those converting to power brakes. I haven't inspected the pedal in my car now, but i would think there would be a part number or some kind of marking on it?
 

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Discussion Starter · #6 ·
Thanks for all the great info guys. I know I have a 69 pedal because I pulled it out of a 69 parts car. The booster came from another 1970 parts car. I'll try to get a 69 booster from Autozone, and use the 70 booster as a core. Is that unethical?
 

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I have a question. Is the '70 booster installed in your car right now? If so, did you have to re-locate the center hole?

You see, I'm not convinced that there is a difference in the pedals, but what I REALLY think (yes, a side by side picture would change my mind), is that the '70 booster was re-designed to fit in the same hole as the ''69/'70 manual brake master cylinder. By redesigning where the booster goes through the firewall, the rod enters lower, thus the straight push rod to the brake pedal, instead of the curved rod of the '69 that has to bend down to the brake pedal.

I found having 2 differnt holes drilled for the '69 odd. What with mass production and all, it just isn't very cost effective. This would lead to the reason for the re-design of the '70 booster ... it would be more cost effective to drill the same firewall hole in every car.

This is just a theory of mine, but I haven't seen it disproven yet.
 

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So you had to raise your booster rod hole 1" approx. The rod has a turn down that is approx 1" below the centerline of the rod. So the different pedals would not be needed. Hm, never thought of it like that. My question is this, have you compared the 69 and 70 boosters in regards to the rod location? I've only seen pics of 69 boosters so i haven't been able to compare, but if the vertical distance from the top mounting stud to the centerline of the booster rod are different between the two boosters then i'd say your theory is correct. I'm gonna do a little more research on the 69 and 70 pedals. I'll get back to everyone on what i find out. Smart man, just too damn smart :lol:
 

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No, I have not had the oportunity to compare a '69 and '70 booster side by side. Doing so, though, would definately prove or disprove my theory.

Of course if my theory is correct, I'm going to be really ticked off, as it would have been MUCH easier to install a '70 booster in my '69 manual drum brake car, than it was to install the '69 booster (I didn't think of this, though, until after the fact).
 

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Hey John I did some checking tonight. My parts catalogs list 67-73 as all using the same power brake pedal. Then I checked my original booster and the pushrod coming out of it is about 1" above the mounting point. Then I checked the new booster I am getting ready to install.It is an aftermarket booster but it is listed for 69-70 Mustangs and the pushrod on it is centered with the mounting points. So I would say you could have used a 70 booster on your car and not had to cut up the firewall. :sniping:
 

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A PM that i received from Scode68:

I took some measurements last night of a 68 and a 70 PDB pedal. I used a dial caliper because it was easier to read but probably a bit more accurate than needed. On the 68 pedal I measured from the bottom of the mounting hole to the bottom of the pushrod stud, 4.915”. Center to center came to be 4.979”. I’m 99% positive the 68 and 69 pedals are identical but it’s been almost 20 years since I compared the two years. At the time I was comparing a 68 PDB manual trans brake pedal to a 69 PDB auto trans brake pedal. The holes, studs and bends were identical.

The 70 PDB pedal is also identical except for the location of the pushrod stud. I measured from the bottom of the mounting hole to the bottom of the pushrod stud, 4.382”. Center to center came to be 4.446”. So the pushrod stud on the 1970 pedal is approximately ½” higher on the pedal. I’m not sure if there are any problems with binding when a 70 pedal is used with a 67-69 booster or vice versa.

I haven’t seen any numbers on the pedals so you can’t check that way. The Master Parts Catalog shows a different part number for each year for the 67-70 pedals but I guess that the rubber pad might have been included. The 67 and 68 pedals are identical also except for the 68 auto pad is wider from left to the right. The metal part that gets covered by the rubber pad is 5” long on the 68-70 auto pedal. The 67 pedal pad is something like 4-4 ½” wide.

I have a 69 auto pedal in my 68 fastback so if you really want the actual measurements on it, it will take me a while to get it.
 
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