40s rpu master cylinder mount

[Jimmy Wallbanger]

I'm havig a hard time finding a way to mount my master cylinder its a 40s GMC I have room under the floor but I'd rather run a simple 180deg under dash. anyone ahve a similar truck with pics I've searched here google and bing without a good pic on what to make. its a new gm master like speed way sales.

 

[Daman]

I used the pedal from the '83 Olds I had and set it up to a 1970 c 10 pickup master cylinder. Here it's mocked up. it now has a bolt through the bar (stock ihc, it was there) and also a cotter pin in the pedal instead of a safety pin

 

[Jimmy Wallbanger]

Looks good ! Nothing safer than a safety pin haha. I'm looking at any and all options right now ready to get this frame done!

 

[Jimmy Wallbanger]

Behind the cab master C

anyone mounting thier master cylinder behind the cab? I have a ton of room and plenty to mount too back there its just the long push rod that wierds me out. you guys runing this method ? I know i have seen one before

 

[deerchooper]

i have a rear mount on my olds. no issues at all. i used 3/4" black pipe with bungs welded in with hiems joints. im not there yet but will do the same thing on my 41 chevy truck. couple weeks and ill have some pics for ya, i hope lol.

 

[Jimmy Wallbanger]

Hey deer chopper!

That's great it should be a similar body. Gotta say the black pipe is a lil scary cause I've seen it fail but I'm sure with 3/4" versus the 3/8 you normally see youll never see an issue. Do you have a build thread

 

[deerchooper]

i got a correction jimmy, i think i used 1/2" pipe.

heres the build of my truck, http://www.ratrodsrule.com/forum/showthread.php?t=16705

heres the one of my olds that i did the pipe on, http://www.ratrodsrule.com/forum/showthread.php?t=14297

 

[cking894]

Here's how I did it. I've been driving it for a year and a half and the brakes work great.

I used the original '41 Chevy brake pedal that I have bolted to the frame. I used the original brake rod and just modified the length. The rod goes under the seat and out the back of the cab.

I hope this helps or gives you some ideas, Keith

 

[Jimmy Wallbanger]

exactly cking!

thats exactly what I was throwing around in my head! cant run mine under the seat thought because it has a piano hinge to flip forward but beside it or same set up under the floor maybe. either way some times original isnt best cause you can see if itll work or not. are the manual brakes alright ? thats my plan too but I figure there is enought room a booster would be an easy add.

 

[deerchooper]

jimmy,
i just got the pedal mounted tonight and started to run the linkage back to the rear. i just need to find a 1/2" die in my garage and ill have you some brake pictures up this weekend. i am also using the oem pedal, 1/2" solid rod and a mid 80's stang brake booster.

 

[cking894]

Jimmy,

The brakes work great without a booster. I can stand on them and the it will lock up the rear brakes and just slide the front disk brakes. If you look at my pictures you can see that the rear portion of the brake mount has a pivot point with the rod going into the master cylinder to operate it. My setup has a one to one ratio. It would be easy enough to change the ratio to have more or less braking.

Keith

 

[Jimmy Wallbanger]

I didnt think about that

changing the pivot point on the bell crank would give more or less leverage. I was thinking that on the when I go to attatch to the brake pedal

 

[deerchooper]

the start of the brakes. the lever is on a 45* right now. it works threw its range of motion.
i think i might redo the linkage/ lever/ pivot arm with 2 arms and a shaft conecting the two on
bearings. 1 arm will be 90* to the shaft and the other arm 180* from the other arm.

the pedal i used a piece of 3/4" solid rod. drilled and tapped for 1/2", welded to the frame with
a bushing.

 

[Jimmy Wallbanger]

cool

looks like the pedal ill be using. i dont get how they stuck that muther through a floor without having a massive hole.thinking my pedal will be sorta like yours and my MC like cking had thanks for the great ideahs guys and glad to see the ball rolling chooper

 

[cking894]

I used the same pedal. It was brackets on it that originally bolted down to the frame. I welded a bracket on the side of my frame and then bolted it down through the floor. By doing this you don't have any holes in the floor for the arm to swing through. I did shorten the brake pedal.

Keith