Power Brake converison '71

[DjS71]

So, I thought I had dotted all my Ts and I CERTAINLY crossed my Is... Got a used setup off a 72 booster + bracket + mc + pedal rod.

That pedal rod seems too short. I know I've seen a thread that had someone using a female hex -> male threaded stud extension on that rod but i can't find it through search for the life of me.... (If you guys find it OR know off hand what the thread size is I can pick one up @ work)

I had it all hooked up and the brake pedal was noticeably lower than both gas and clutch pedals. Also, at rest it drags the linkage so that its touching the firewall, and i don't think that is the way its supposed to be.

(307, 3-on-the-tree)

One more question, on the back of the booster itself, there is a boot that covers a plastic cylinder that surrounds the push rod. The boot is well.... old and busted, and i can see a crack in the plastic cylinder. Do I need a new brake booster?



Thanks in advance.
~Dan

[hddavis]

i have been looking for the same thread for a week now. i believe it had pics of rod also but i can not find it. if some one has the length maybe i can make one a pic would help to

[RichardJ]

Here is a picture that teeitup posted from a '71 that he is parting out.

[DjS71]

Doesn't do too much for us, but thanks for the pic. (Actually it helps on the other bracketry, thanks!)

Though... my booster isn't as round....

Maybe I'll go snag a couple different lengths from the hardware store and see what i come up with.

Until then, hopefully someone can dig up that fossilized thread for the both of us.

[Hottrucks]

thats funny I bought a booster from him and it was bad I have been waiting for him to get another??

anyway As far as the rod goes you need to use the one with the booster not your old one I ran into the same issue..also make sure you check your brake light switch for adjustment when your done....

there is no real check for a booster.....its hit or miss its nothing but a big rubber diafram if it leaks then your brakes will be hard..they will still work but very hard..

[hddavis]

any idea of a company that sells the pedal to booster rod?

[petey-pablo]

I did this upgrade to my truck 72chevy and well you have to use the new rod that came from the power brakes set up because the rod on the non power set up doesn't work, and it should all bolt right up with no problem.

[Hottrucks]

who ever you bought the set up from???? or your going to have find used...I'm not sure if any of the new models fit??

[Tynee]

If I remember correctly from converting mine, nobody reproduces this part. Used is your only option. I got lucky and a local member, Huck, found one at a salvage yard for me a couple days after I posted a WTB on here.

[DjS71]

I used the one that came with the used setup i bought, perhaps i was given the wrong one... hmm....

In regards to my other question, I'll take a pic when i get home, if the little woman doesn't have me running in circles again...

[Tynee]

As far as I remember, the only difference between the power and the manual pushrods, is the eye on one end to attached to the pivot that applies pressure to the Booster pushrod. The length SHOULD be adjustable. Can you lengthen the rod enough to get your pedal to a functional height?

[DjS71]

It's 7/16-20 Thread, which apparently has been forsaken by most hardware stores...

My other issue

Does this = new booster time?

~Dan

[sept987]

This might help probably not, but I got one off a 79 pickup, and installed it. I needed to make the rod 2 inches longer, and never have had a problem.

[Zeke]

Here's a link where you can get 7/16-20 threaded rod, they also have it in stainless for more$
http://www.use-enco.com/CGI/INPDFF?PMPAGE=780&PMCTLG=00 oil finish low carbon steel
http://www.use-enco.com/CGI/INPDFF?PMPAGE=778&PMCTLG=00 stainless

and 7/16-20 coupling nut
http://www.boltdepot.com/product.aspx?cc=7&cs=181&cm=6

[DjS71]

Alright, I had one of the guys @ work weld a nut to the back of a 7/16-20 bolt, little redneck, but cheap & easy. Now, @ rest against the pedal stop (plate bolted to underside of dash) i can get the pin in & out, is this where its supposed to sit with no outside pressures on it? Can anyone snap a quick pic of an in-use pb on their trucks?


and heres the pic for my last question: Does this mean i need a new booster?

[Tynee]

Originally Posted by DjS71

Alright, I had one of the guys @ work weld a nut to the back of a 7/16-20 bolt, little redneck, but cheap & easy. Now, @ rest against the pedal stop (plate bolted to underside of dash) i can get the pin in & out, is this where its supposed to sit with no outside pressures on it? Can anyone snap a quick pic of an in-use pb on their trucks?

Sorry, I don't have a pic handy, but it sounds like you've got it where you need it. Do you have any free play before you start to feel the brakes engage (I guess that's kinda hard to judge with the booster laying on the ground in pieces).

Now tighten everything down, and see if your brake lights go out. If not, you'll need to adjust the brake light switch down to the pedal. And just because they are out now, doesn't mean they are going to go out when you press the pedal and let it return naturally. I went through a period after I installed mine where I had to pull up with my toe to get the lights to go out, until I got a chance to get back under the dash and adjust that switch.

Originally Posted by DjS71

and heres the pic for my last question: Does this mean i need a new booster?

I think so, but I'm no expert.

[Hottrucks]

heres what mine looked like before the install you can see what the rod looks like...like I said before I'm looking for another booster.. put that one in and see if it works ?? if so great if not then lok for another and you'll have to deal with the hard pedal till you swap it

[RichardJ]

djs71, that booster is from a van.

[DjS71]

Mine or Hottrucks? Also, does that make things difficult?

EDIT: Clever editing skills, RichardJ.

[Hottrucks]

that maybe why your peddle rod is funky??? Mine came from a PU I think like I said it came from a board memeber

[Longhorn Man]

no one has mentioned that you have to install the pushrod on the other hole in the pedal arm.

[DjS71]

There is only one free hole in my pedal arm. (2 technically but the upper one is the pivot point)

I'll bolt it all back up and break out the vacuum pump and see what happens with the booster.

[DjS71]

Put Vacuum to 'er and No dice.

Whilst I ponder what to do with that, I tried to get the pipe plug out of the manifold behind the carb so that when I get a new one, the vacuum line is already run. Stuck solid.

While I'm in there I look down at the alternator bracket and see a whole mess of washers behind it. I assume this isn't standard operating procedure?

Bring on the snowball.