I bought a new power brake booster from an auto parts store for my 71 El Camino. I painted it the same color as the car and installed it. When I hooked up the brake pedal, it is about an inch and a half or so short of hitting the bumper. The auto parts store rechecked and they say I have the right booster. I see some stores sell a extender kit for around $40. I cant find a coupling nut in the right size (3/8 x24), I dont need all the extra ends that come in the kit. Any ideas?

There are two lengths pushrods used depending on the depth of the hole in the master cylinder as I see you've found out.
I think I've got a longer pushrod around if you can't find one locally.
Either that or you'll have to change out the m/c. Generally the manual masters have the deeper hole to retain the pedal pushrod.

I had that same problem with my power brake conversion on the '72. I thought maybe the disc brake cars' brake pedals had a different bend in them to get closer to the rod. Not sure. I'm using it the way it is now and would prefer to get it back resting on the pad as well. I'd be real careful with any kind of extender nut or something that cold come loose. A friend of mine actually welded any extention piece on his. It's definitely not a master cylinder issue.

The application is correct. It is not necessary for the pedal arm to rest on the stop with power brakes. The pedal on the power brake set up sits lower than manual brakes.What you are going to need is the stop light switch bracket that bolts to the pedal to make up the difference in pedal height so the stop lights will shut off. It will bolt into the hole the manual rod fit into.

I have currently found I have the same short-pushrod/deep-bore mismatch problem also. I simply measured what I needed and had an extension made for my booster's pushrod, but you can buy them from some brake component suppliers. (http://www.classicperform.com/)
Here's my story with pictures..(Scroll through the thread and you will see required dimensions etc)
http://forums.hotrod.com/ubbthreads/showflat.php?Cat=0&Number=152027&an=0&page=0#152027

http://www.classicperform.com/TechBook/BrakeTroubleshoot.htm#pushrod
http://www.classicperform.com/TechBook/master_adapter.gif

He's not saying it's too short between the booster and master. It's too short between brake pedal and booster.

Oh sorry.. :clonk:
Maybe something here will be of use..
http://www.mbmbrakeboosters.com/bracket.html

I just finished doing a disc swap on my 68. I changed out the stock booster/master, so if you still need the booster rod send me a PM and I will send it to you.

Pat

I've got the exact same problem on my 68. Went from a Bendix to a Delco booster. The Delco booster-to-pedal rod (and clevis) is shorter. Those pedal extenders from
http://www.mbmbrakeboosters.com/bracket.html would be perfect to get the pedal height back up... if they sold them to the public. Have to be a dealer to buy them.

BTW, my old Bendix booster had an adjustable rod for the Master Cylinder... a good idea

buy a lathe and make your own

you won't be sorry with a good lathe, i promise! I don't know what i'd do if i didn't have mine; things like this are no big deal anymore...i just wip up the part i need. Very handy and cost effective.

What 64elcamino said is correct. You have the correct stuff. It sounds like you changed from non-power brakes to power and are now puzzled about why the pedal is low. That is the normal situation. Now what you need is the "striker" that hooks to the brake pedal and contacts the brake light switch in the new position. Some folks have simply put a sheet metal screw into the end of the brake light switch to make things contact properly. (The power brake pedal never hits the bumper from the non-power system. )

What 64elcamino said is correct. You have the correct stuff. It sounds like you changed from non-power brakes to power and are now puzzled about why the pedal is low. That is the normal situation. Now what you need is the "striker" that hooks to the brake pedal and contacts the brake light switch in the new position. Some folks have simply put a sheet metal screw into the end of the brake light switch to make things contact properly. (The power brake pedal never hits the bumper from the non-power system. )Not trying to steal the thread, but are there different pedal assemblies for power brakes in manual transmission cars? With a clutch, I didn't think you could use a wide power brake pedal. From that, I assumed that the pedal assemblies were the same for power or non-power brakes, in manual-transmisssion cars. Am I wrong?

the connecting rod goes in the bottom hole and there is a bracket that bolts in the top hole for the power brake setup remember when changing from manual to power brakes to get the brake pedal out of the donar car also it will have the bracket already on it