Any advise would be great. I watched Dons video on the different versions. If anyone has do this job befor, please advise, I haven’t done this befor so any help would be great,
Thanks
1970 cougar convert.
Well, I’m currently in NC and my Cougar is in TX at the moment so I can’t go look at the parts in question. From memory, here goes:
You will have to remove both Brake lines at the Master Cylinder and remove the two nuts holding the master cylinder to the brake booster. Remove the MC as it will be much harder to remove the brake booster with it still installed. (And you have to remove it anyway)
Remove the bolt or nut (can’t remember which) from the engine compartment side at the top right of the brake booster where it attaches to the firewall.
Remove the clip holding the brake light switch and brake pedal to the brake booster pushrod inside the car. Then remove the 4 nuts holding the brake booster to the pedal assembly at the firewall under the dash. These can be a little fun to get to.
I think you can leave the little 1/4" sheet metal screw/bolt in the pedal assembly that goes thru the firewall so that the pedal assembly stays in place. You should be able to pull the brake booster clear of the firewall once you remove the vacuum hose from the check valve on the passenger side front of the brake booster under the hood.
Replacement is in reverse order and don’t forget to bleed the master cylinder (if you replaced it too like I would–cheap insurance) as well as the brakes when finished.
Oh and also while the booster is out check that the booster push rod on the new one is identical including length to the one on the old brake booster.
Enjoy quality time out in the garage!
How hard is it to get the 4 bolts inside the car out? Any tricks? What kind of time is the R&R ?
Thanks
Al
Two thoughts…
[Of course you have removed the driver’s seat for this job and I also like the bottom back seat out so I have more room to wiggle around on the floor; I put a couple of blankets down in front of the seat riser to make the floorpan more “level” to work on the inside. The engine compartment-side stuff is the easiest.]
[And I have only done #2 '69s (Mustangs), so the '70 might be different…I have not seen the videos.]
So to answer your question – the #4 nuts SUCK to get off and take forever, like a quarter turn at a time! Persevere and take some extra ibuprofen when you go to bed or your arm, shoulder, and back will be extra sore for a couple of days. They are kind of like removing nuts that cut threads into the bolt? I thought it was a b!tch to do, but if I can do two of them, anyone can do it! 
And two, in a '69, there is a bracket that attaches to one of the studs on the booster under the dash…you will remove this nut and think “cool, that one wasn’t bad.” But the booster won’t budge when you get the rest of them off. So you have to remember to get the actual booster nut behind the dash bracket also.
One thing I found to be helpful is the use of a 12 in. 3/8 extension with a 9/16 universal socket.
The one thing that will hang you up is the stud at 5 o’clock. When you take the nut off it will perplex you on why the booster will still not budge. Keep in mind it is double nutted, there is a second nut under the lower dash brace.
Thanks all!
I planed on taking out the front seat, was going to pull the back seat to see if the build sheet is there anyways
Al