Power Brake Booster Adapter Bracket

[Chuck78]

Capt, I sent you a PM yesterday, but I noticed today in my sent messages that it was not there... I hate it when that happens.

I started working on a booster bracket for my 62 so that I can fit a hydraulic clutch in the stock clutch master cylinder location 2.5" to the pass. side of the brake pedal pushrod. I was going to use some random steel that I have laying around to extend the $5 brackets that I bought with the Pirate Jack's 8" dual diaphragm booster, but then I just decided to take a used 89 suburban booster and chop the bracket off of it and graft them together.
I've got it tacked together, but it was 4AM and the neighbors probably don't appreciate a lightning show as I don't like to weld in my cluttered garage. I made it 4-5/8" long, no offset on the angle at all. The clutch master I'll be using is, like I said, a $32 1962 auto trans truck single reservoir brake maser (removing the residual valve), and it requires clearancing the firewall mounting flange of the booster bracket, so I made it so the bracket extended upwards more on the firewall so I'd have an upper bolt location above the clutch master mount, which has the diagonal 2 bolt pattern vs horizontal (or vertical like the $65 Wilwood master of the same physical size).

If you made up a set of brackets like this, and decided on a standard booster to use with them (or even make the brackets slotted like the ones I bought to chop and extend), you could then figure on a pushrod length and fab up that.
The astrovan/safari 85-87/89? boosters are a good looking 9" dual diaphragm booster with a little longer pushrod, and have the short master cyl pushrod for newer masters and most disc/drum masters past the early 70's. The 68 or so 9" truck dual diaphragm booster (look up 68-70 C30/3500 trucks, some burbs and pickups also) is also a great bet, and has the longer master cylinder pushrod for the older masters that still used the deep bore like on a manual brake truck. If doing 4 wheel drums, one would most likely need this type of booster so they can put a deep bore drum brake master on, and also, 71-72 trucks had deep bore masters as well and front discs/rear drums, so this $120 or so booster would be good for both applications as long as you were okay running a master that was only made for 2 years or so on a disc/drum application. The parts stores still can get these no problem. If you switch later, you can always stuff a rag in the booster's master recess, and chop the pushrod off shorter and grind the end down to a nice round. Some boosters have a pushrod that just sits in there in a socket and you can pull it out.

I got the pirate jack's "MBM" brand (aftermarket repro manufacturer) booster because it had a 3/8x24tpi threaded pedal pushrod, and I thought this would be easier to make work, as it's a standard but not so common thread, and bicycle axles on rear coaster brake wheels come in hardened steel 3/8x24tpi, so I thought with some of the rod couplers Pirate Jack';s sells, and maybe one of their pedal rod extensions, I could make that work easily.

I took the manual brake pushrod off mu truck, and although the pin that goes intot he master is slightly tapered, I tapped a 3/8X24 tpi thread on it, but turns out I didn't have enough diameter until about halfway back on the taper to get good thread depth, so the 1-1/8" rod couplers wouldn't thread on far enough to get to the good threads, and I didn't want to chop up my original parts to mod them for this use. So I used their $14 truck pedal rod extension that's a 5" long solid sleeve with 1.6" of female threads on each end, and a heim joint for the pedal pivot with 1-1/2" of male threads on the end of it. re-tapped a longer 3/8x16 rod coupler to 24tpi, threaded onto heim joint all the way, leaving 1/2" left to thread a bicycle axle in. Since the threads were somewhat questionable due to the nature, I'm drilling a hole on the flat on the hex coupler, right at the butt of the two threaded pieces, and plug welding all three together there.

Now for what I would have really done, after doing it... The Pirate Jack's booster takes a slightly narrower master than I realized, so I had to either oversize or elongate my master's bolt holes to fit onto the 3/16" or so narrower bolt pattern. That on top of spending $19 on pushrod parts ($14 on heim joint with long rod coupler, $5 on axle), I think now I would just be inclined to do the following.
My 89 suburban booster pedal pushrod is a thick 1/2" of 5/8 shaft with a big flat that mounts similar to the 62 pedal with a large shoulder bolt with a smaller 3/8 thread. Hole needs drilled slightly larger in this piece, but works. This is about 4" long, and has I think a female 3x8 x 16 thread on it, and then the booster pushrod comes out the same size up to the firewall before it reduces to 5/16 with a ball and socket on the end inside the booster, and attaches to the pedal section of the rod where it has a male 3x8x16 thread. I'd snag this pedal piece, and then use some cold rolled steel bar stock about 1/2" and cut a nice square end on it, and then take a long hardened steel 3/8" hex head bolt and weld the head to the end of the rod, and thread into the 89 suburban booster piece, so that you could have a washer and jamb nut on it for a little adjustment. On the other end at the booster, pushrod has again the flattened out flange for a thru-bolt or clevis pin that looks like it attached to the pedal there, and on the older truck unit, to the pivot linkage. On this end, I would determine the length with bracket and all, and grind two flats on the sides of the end of the rod, and weld two flat pieces of steel to the sides to make the outside portion of the clevis piece, and drill it out and get a clevis pin and cotter from Lowe's.

Also, if you were worried about reducing the pushrod down from 1/2"+ to 3/8 at the end of the booster piece, you could use 1/2" "all thread" threaded rod instead of cold rolled steel round bar stock, and put a 1/2" rod coupler in the middle of that with a jamb nut on either end.

this is the 89 suburban booster that I had laying around, you can see the booster side of the pushrod, and the other piece threads onto it and goes to the pedal. This is also the booster bracket that I had to chop up and graft to the other booster bracket to make one long one. I'm sure Capt Fab could make something much slicker looking with some flat steel plate!

Oh, the pedal pushrods on our trucks are a 7/16 thread, I think 7/16x24 tpi, so it is possible to reuse the same pedal attachment piece if you could find a die or some threaded rod that size. I don;t think I remember seeing that size in my tap & die set.

Food for thought, let me know if anyone else has any ideas or questions, or if you want anymore advice, capt!

The pushrod centers of the stock master are 2.5" apart, and the new clutch master will fit in the stock firewall hole with new mounting holes drilled (theres even an indentation in the firewall there on mine?), but since you are just routing a pushrod through the brake hole in the firewall instead of a large master cylinder bore register piece, you can slide the booster slightly towards the fender before drilling the firewall for the booster bracket, and this gives you a slight bit more clearance if using the $32 1962-3 single res. brake master for clutch. If using the $65 Wilwood master of the same physical size, the bolts are vertical instead of diagonal, so this probably isn't necessary. If changing the angle and not using a heim joint at the pedal, you'd have to then stick a few flat washers under the shoulder bolt at the pedal attachment, or maybe it could move to the other side of hte pedal arm to re-align.

a few S10's used a 9" dual diaphragm booster also, as well as I think 77-80 or 77-81 vettes (different pedal pushrod connection), and many other GM vehicles. I recommend the dual diaphragm for clearance reasons if you have a big block or GMC V6, and also for more stopping power. Keep it simple for the Capt, by sticking with one or two boosters to fab the stuff up for.

Good luck anyone who tries this, and Capt, if you want to try and make these, and need more info from me, let me know. bracket should be about 4-5/8" or so, but if moving the booster 5/8" towards the fender, you could really shrink it down to almost 4" with the particular clutch master and booster I'm using (not the ones I recommended above, need to check the fit of those).

[Chuck78]

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89 burb booster that I stole the other part of the pedal pushrod from, and chopped most of the bracket off of to graft to mine. These boosters were used 81-91 on trucks and vans, so that's a lot of vehicles in the salvage yard that you could look through to find the half that attaches to the pedal, if you choose to go that route.

[Captainfab]

Sent you a PM Chuck......

[Chuck78]

Got my bracket welded up today, planned on moving the brake stuff over 1/4" so that I wouldn't have to notch the bracket anymore than the firewall flange, due to the clutch master I'm using. Since I'll have 2-3/4" center to center brake and clutch, I really could have shaved 1/2" of length off of the booster bracket, but I didn't plan that far ahead. I would venture to guess that Wilwood master would allow the stock 2.5" spacing due to better/more compact mounting flanges.



the wilwood only comes up to a 1" bore, and ours are 1-1/8", so you would have a softer pedal with a more spongy travel, but I think if you drop down the pushrod location where it attaches to the cross-shaft's lever linkage, this will give you more stroke, which this master is capable of, and that will most likely compensate for the slightly smaller bore.

Capt, if I can find a digital camera around here, I'll take a pic or two for you of my setup. Got the brackets grafted together. what a tedious operation that was. It would have been far easier to have just done it with some flat plate steel from scratch I think due to angles, contours, and re-aligning two halves of existing booster brackets. Looks alright now, but I opted not to smooth the weld out, as I'm sure it will spawn some conversation on the subject somewhere along the way with a non-factory looking weld down the middle of my booster bracket.

looking at that wilwood drawing, I realized that the other drawback besides twice the $$ is that now you'd have to make up a 5/16x24tpi pushrod for the clutch, where using the 62 unit that is heavier and has a wider bolt flange, it uses the exact same stock setup for linkage and pushrod. The 62 single brake master in this location has the bolt flanges diagonally, and has 1/2" greater distance from edge of flange to center of pushrod (1-3/4" roughly).

check out soba_03's pictures, but I think the Wilwood's outlet is on the engine side of the master's end, and requires a brass 90 degree elbow as well, but should clear the contour of an 8" booster and maybe some 9" dual diaph. boosters if the contour of the back is good for this. 4.87" plus clearance for a brass elbow if necessary, where the factory unit is a little over 4-1/2" long.

it's late, gotta hit the hay.

[Captainfab]

Ttt

[pedro6371]

im kind doing the same process but im using a 4 speed saginaw trans,i have a 1960 chevy truck with same style master cylinder but im swaping a 78 chevy crossmember with disc brakes any suggestion for my swap never done it before thanks .pedro6371

[Captainfab]

Originally Posted by pedro6371

im kind doing the same process but im using a 4 speed saginaw trans,i have a 1960 chevy truck with same style master cylinder but im swaping a 78 chevy crossmember with disc brakes any suggestion for my swap never done it before thanks .pedro6371

What do you need to know? there are several threads here on the disc brake swap. Plus you are likely to get more responses if this was posted on the '60-'66 message board instead of in the classifieds.

[pedro6371]

the only only thing it may be a problem is my truck use to be six cyl with a three on tree now i have 283 with a 4 speed saginaw,originally on the truck is master cyl with a clutch cyl. i dont know how to do the linkage for the new set up and how to attache it to the pedal the brakes i think i can handle it,if you have any answer thanks.

[Captainfab]

Originally Posted by pedro6371

the only only thing it may be a problem is my truck use to be six cyl with a three on tree now i have 283 with a 4 speed saginaw,originally on the truck is master cyl with a clutch cyl. i dont know how to do the linkage for the new set up and how to attache it to the pedal the brakes i think i can handle it,if you have any answer thanks.

OK, so if I understand you correctly, you are wanting to convert to a disc/drum brake master cylinder but don't know what clutch master cylinder to use or how to connect them to the pedals.....is that correct? Do you want to have power brakes?

This is something that I have gotten only part way with designing a bracket for. It will most likely be a couple of weeks or so until I have something that would work for you. If you need something right away, take a look at what Slepysal did for his clutch master. That is most likely the similar direction I will be going with my design.

Here is the link to slepysal's conversion....
http://www.67-72chevytrucks.com/vboa...d.php?t=341247

If you need more help let me know.....

[owen13]

doesnt the 63 gmc use the same clutch/brake master combo as the 60-62? if that is the case i may be interested in a conversion bracket to retain stock postitioning as well.

[Chuck78]

Look at my thread, tons of info to keep the stock clutch linkage location, and one of the other guys on here (slepysal?) did the other conversion with the compact clutch master relocated toward the fender. Eitehr should work, mine will probably match up to the original slave cylinder a lot better, but the other seems to work well also (I think the bore might be 7/8" or 1" on the other setup, stock is 1-1/8".

[gopackamx]

I'm needing a pb mount and a couple of ps brackets for a 65

[Captainfab]

I'll send you a PM with ordering and payment info.

Originally Posted by gopackamx

I'm needing a pb mount and a couple of ps brackets for a 65

[racingdewman]

Originally Posted by Captainfab

I'll send you a PM with ordering and payment info.

i purchased a CPP booster and master cylinder combo for my 64 c10 full disk conversion. what bracket option will i need and do you have any current picture of bracket? Price also.

[Captainfab]

Here are a couple pics that are more up to date than in post #1. The price is Exactly the same as in post #1. The only options available are satin black powder coating or if you need the hydraulic clutch conversion.

Originally Posted by racingdewman

i purchased a CPP booster and master cylinder combo for my 64 c10 full disk conversion. what bracket option will i need and do you have any current picture of bracket? Price also.

[DPowers]

PM sent on bracket

[DPowers]

Received mine today- Thanks

[eldogg]

Got mine today!! Thanks Captain FAB!!!!!!

[Captainfab]

Thanks for your purchases Eric. If you have the time post up some pics of your installs.

[bubba327]

Captain ---brackets arrived today and look great!!! Very nicely packaged and Quick shipping. Paypal made transaction easy.. Thanks again

[Captainfab]

Cool! I'm glad you're happy Bruce....I try hard to provide the kind of service I like to receive.

Thanks for the purchase

[Captainfab]

Bump!

[LeftCoast32]

I will take one for my '66 K10 in Satin Black Powdercoat. PM sent with shipping information.

Joe

[Captainfab]

I sent you a PayPal invoice Joe

Thanks

[VA72C10]

ttt to remind me about this