HELP! -- Brake Booster Install Question

[ajgriffin]

Ok, I'm trying to install a booster from a 71 big block burb into a 69 small block C10. I got the master cylinder off and disconnected the brake pedal, but then I noticed that the bolts that the master cylinder were mounted on are tac welded into the firewall. Do I just have the wrong part or is there a way to safely remove the bolts? Any help is greatly appreciated. Here are a couple of pics

[petey-pablo]

You do not need to remove any bolts you are are missing a braket that the booster sits on. heres a picture of mine not a good one but you can barely see what I am talking about I will keep looking for a better picture.....

[petey-pablo]

Here are some more pictures where you can see the bracket.. Just make sure you got the rod from the booster doner as well because Power brakes rod is different...

[ajgriffin]

Thanks for the help! I thought that might be the case, but wasn't for sure. I didn't get the rod from the doner either. if anyone has the mounting bracket & rod out there send me a PM.

[ajgriffin]

Ok, I have all the parts now, but the rod to connect to the panel came in pieces & its not exactly intuitive to me how they all go together. Does anyone have pictures or can you tell me how they go together? Here's a pic of what I have. The first are the parts that I just bought that should make up the new rod & the second is what the original rod looked like.

[ajgriffin]

ttt, Can anyone help me here?

[mclairmo]

Small top hole connects to rod coming out of booster with clevis pin and big bottom hole conects to bracket with that big shaft with square end. Middle hole connects to push rod (small end of it) that goes through firewall and connects to your pedal (with the big and and shouldered bolt) similar to original manual set up. Be sure to clean and lube everything.

[KrazyRay]

trying to send pics

[KrazyRay]

pics

[KrazyRay]

Let me know if these pics work for you.
Ray

[dave2953]

Make sure when you attach the rod to the pedal (top left of last pic that KrazyRay posted) that you don't get the nut too tight. If you do, the pedal will drag. It only needs to be tight enough for the cotter pin to pass through the bolt.

[ajgriffin]

Ok, so here's how I think it should go together. I come up with some spare parts though...what's the extra bolt and cotter pin for? Also, what holds the bracket together? I don't have the piece that go in the grooves for the 2 bolts at the top left of the picture.

Originally Posted by dave2953

Make sure when you attach the rod to the pedal (top left of last pic that KrazyRay posted) that you don't get the nut too tight. If you do, the pedal will drag. It only needs to be tight enough for the cotter pin to pass through the bolt.

Dave, any good recommendations on lube?

[mclairmo]

The very large bolt at far right top corner of pic goes into large bottom hole of the arm at left side of pic and the booster to firewall brackets, which you have not shown on your pic but are shown in pics by KrazyRay. Two small bolts, as you call them, are retained by two square shaped retainer clips. You can buy replacement pins/bolts at any hardware store that have holes in them for cotter pins instead of the oem square clips or try to find those oem square clips.

[bluec10]

Gotta love the board. This is exactly what I'm working on right now. Thanks for some really helpful pics guys.

[ajgriffin]

Ok, so I got everything all buttoned up and from the looks of things its all installed correctly (I push the brake, there's lots of pressure, the brake lights turn on, & I can see the rods moving inside the engine compartment).

Only problem is this...the brakes still feel the same when I'm driving! Is there some kind of rookie mistake that I could have made? Any help is greatly appreciated.

[mclairmo]

What's the problem? Are you saying it still feels like manual brakes? Is the hose hooked up from the booster to a full manifold vacuum source?

[ajgriffin]

Originally Posted by mclairmo

What's the problem? Are you saying it still feels like manual brakes? Is the hose hooked up from the booster to a full manifold vacuum source?

No it isn't and I can't say that I know what that means. I do know that I don't have any plumbing to be able to do it even if I wanted to. Can you give me an education on what I need to do? I'm digging in my Haynes manual now to see if there's anything in there on it.

[bubba327]

You have to have a vacuum source for the booster to work. intake Find a vac port at the manifold or the base of the carb and connect the hose to the booster. When you start the truck you should feel the booster engage and the brake pedal soften if the booster is working properly

[westofb]

On the vac booster there is a hole (if looking at it from the front of the truck it is located on the front, to the left of the mastercylinder) that is too be hooked up to full manifold vaccum. There is a round piece with a nipple on one end (that goes into the vac booster hole with a rubber gasket making the seal) and on the side of it is another nipple where a hose goes to the intake manifold. Some of these contain one way valving to only allow vac to travel one way (was designed that way so if you were driving down the road, the booster would have enough vaccum on tap to allow you to stop with power brakes in the event of engine failure). Some do not contain this valving, in those applications the valving is in a separate in line valve that looks similar to a large plastic gas filter. OEM power brake vehicles had the vaccum source on the engine hooked up to the rear of the base plate of the quadrajet carb. This is the easiest way to hook it to a vac source if you have a quadrajet, carter, or edelbrock carb...some holleys do not have this vac source built into the base plate of the carb. This is hard to explain, much easier to look a a friends vehicle to see how everything hooks up, I know all rear wheel drive gm cars and trucks with carbs or throttle body fuel injection had similar vac routing from the booster to the carb...just look and you will see what you need from a salvage yard. If you have a quad, carter or edelbrock carb, they will have a plug blocking off this vac port, you will need the adapter from the donor vehicle that screws into the back of the carb. Look at a buddies vehicle to get an idea what you need then go to salvage yard and get all your parts!

[mclairmo]

There are several ways to get full manifold vacuum hooked up to the booster, one is to use the large nipple at the base of the carb, if you have one available. Sometimes, the pcv hose is hooked up to this nipple on the carb. If this is not an option, you can install a 90 degree nipple on the intake manifold, but not in a coolant passage. Must be a hole going into where the air and fuel passes through. Spectre makes a chromed 90 degree nipple that is sold at Kragen and Autozone that works well for this. Use teflon tape to seal it. I have this on my truck. Or, you can piece together a similar set up from the brass plumbing section of most auto parts stores. Or, you can buy a carb spacer that has a hole tapped into it in the back to allow for a nipple to be installed. Again, Spectre makes one with a hole in it. I have it and it works well.

[ajgriffin]

Ok, so here are some pictures of my carb and intake. Can you all point to where I should install this thing? Its not obvious to me & I don't have a buddy's truck available to look at. I'd like to avoid adding the baseplate beneath the carb since I wouldn't know if I'm breaking something. The last picture is from the firewall side of the carb. I couldn't get my head back there to see so I just used the camera.

[westofb]

I can't see a vaccum port on your carb or manifold, you are either going to have to by the base plate with the brake booster port, or remove your carb and drill and tap a hole on your manifold....I believe anywhere in the intake runners would work, you are just in need of full manifold vac....just have to miss the water jackets, should be able to see good place to do it with carb off. Might be easier to just pony up for the carb spacer plate...lol.

[Rack Man]

You see the nipple sticking out of the manifold...between the back of the carb and the distributor cap...You should have a place near the same area where you can thread in a similar nipple (there may be a plug currently in there)...then you can hook up a vacuum hose from there to the booster....then you should be good to go!

[mclairmo]

Your carb is a Holley 4160 and has a large nipple sticking out of the base plate on the passenger side at the back of the carb, the one spot you did not take a pic of. Looks like your pcv valve is hooked up to it. You can run a T in that pcv hose and then run a hose to the brake booster or buy a 90 degree nipple and place it in the intake at the back of the intake exactly where Rack Man shows it should be. There might be a plug screwed into the intake in that hole and you may have to remove it first.

[mclairmo]

Also, not sure if you are still working on these items, but it looks like your detent cable for the trans is not hooked up. This will prevent the trans from kicking down when you floor it. Also, your choke plate is open. It should be closed when the engine is cold. If it stays open, then it may be hard to start when cold.