babys been backed in a corner!!

[marc williams]

Hey gang, I have a 68 charger that is giving me and my mechanics a fit!!
This was an original disk front car drum rear. bought it and it had SSBC disks up front. cam dropped my vaccum and my booster does good on the highway but city...U know.
I recently purchased the MBM disk kit for the rear with e brake. Went on fine but never got a pedal. Mechanic time.. now he's about to give up on it. almost. The brakes work.. its something in the system. mixed part names, I just don't know

 

[Lee Robinson]

Hey gang, I have a 68 charger that is giving me and my mechanics a fit!!
This was an original disk front car drum rear. bought it and it had SSBC disks up front. cam dropped my vaccum and my booster does good on the highway but city...U know.
I recently purchased the MBM disk kit for the rear with e brake. Went on fine but never got a pedal. Mechanic time.. now he's about to give up on it. almost. The brakes work.. its something in the system. mixed part names, I just don't know

 

[Lee Robinson]

My son has a 71 Swinger with a 360. I believe he put an electric vacuum pump from a
VW in his car. This raised his vacuum as his brakes never performed that well. He has
a 73 up Mopar disc set up in front. He is a mechanic so he knows more about this than
me. Lee

 

[GetX'd]

Welcome to FBBO - sounds like you have a problem project on your hands. How about pics of the car.......

 

[Zeppelin264]

Need to setup a separate vacuum pump if your trying to keep the cam and still want power brakes.

 

[marc williams]

won the world of wheels mopar of the show Chattanooga 2016

 

[mr. b]

welcome to FBBO nice looking charger good luck with your brakes

 

[Yatzee]

Hey gang, I have a 68 charger that is giving me and my mechanics a fit!!
This was an original disk front car drum rear. bought it and it had SSBC disks up front. cam dropped my vaccum and my booster does good on the highway but city...U know.
I recently purchased the MBM disk kit for the rear with e brake. Went on fine but never got a pedal. Mechanic time.. now he's about to give up on it. almost. The brakes work.. its something in the system. mixed part names, I just don't know

You say disk up front and disks out back. Did you change the master to handle the additional volume of brake fluid? How many pistons are you trying to operate at one time and what's their size. How much vacuum do you have at idle? Does the pedal hit the floor? And how did it operate before you went to rear disks? I take it that this situation is not new rather the same as before changing the rear brake system.

 

[super-bee_ski]

BTW:
"NOBODY PUTS BABY IN THE CORNER"
NOBODY!

 

[The Rebel]

Had a similar issue with my 68 Charger. Aggressive cam and not enough vacuum. Previous owner upgraded the front breaks from drum to disc. They installed the Master Power Breaks Legend Series. Had to pump the brakes to get it to stop like the MC died. Rear is still the orig. drum setup.

https://www.mpbrakes.com/productcategory/dodge-charger-1968.asp

Had to install a vacuum pump.
https://www.mpbrakes.com/accessories/silent-drive-vacuum-pump-ac9001k.asp

 

[Car Nut]

aboard!

 

[Budnicks]

Nice looken' 68 Charger

welcome to FBBO from hot, dry & sunny NorCal

This is the welcome wagon, it's not really a Q&A Tech section,
not anywhere as many viewers either
maybe post the questions in the either the General discussion
or
Better yet, the Brake, Suspension, Rims & Tires forum section
or review a few posts there, or use the search box option
on the top right of the page, someone here has gone thru that,
already I can guarantee it...

Wrong MC, wrong Distribution block & hold off/residual valves
could be an issue too...
Sounds like a Lack of vacuum to operate properly, is most of it...
Not knowing exactly what you've done or the previous owner did...
When you post the questions add as much info as possible,
photos help a ton too...

Good luck

 

[Paul Boucher]

Welcome, beautiful Charger, and good luck. Guys on here will point you in the right direction.

 

[Xp29h]

Had similar issue with 69 charger. From what I finally found, do a little research on what you currently have for parts. Master cylinder, booster, proper valve (if any) before putting in an external vacuum pump. Make sure they are what they should be. Don't take the work of the p.o. as correct.

I had the external pump, booster, mc etc.. And no brakes with wilwood discs all around. I messed with it for a long time to get some pedal. Still nothing with ext. pump on. I finally checked the pump 25 inches as supposed to be. As it turned out the master was wrong one for system (manual brakes) and believe it the master pushrod had been installed backwards scoring the cylinder and leaking into the booster. I went brand new wilwood mc and took out the pump and brakes work.

Sorry for long story but with what I've found already, you just never know what has been done to these cars before we get em!

Good luck!

 

[marc williams]

You say disk up front and disks out back. Did you change the master to handle the additional volume of brake fluid? How many pistons are you trying to operate at one time and what's their size. How much vacuum do you have at idle? Does the pedal hit the floor? And how did it operate before you went to rear disks? I take it that this situation is not new rather the same as before changing the rear brake system.

the master is from an early eighties corvette so the fittings would agree with each other, large bowl in rear, small in front. brakes felt ok before with the disk f. drum rear. Now the vacuum, 7-8lbs merc at idle because of hi lift comp cam "I just had to have..."lol, but I think I can overcome this using a previous post regarding a vw electric vacuum pump. Front are SSBC look like dual piston, and the new rear setup from MBM is a single piston with e-brake. (drivers side is too short to attatch to e pedal cable by about 6". The pedal driving is spongy. three pumps and its adequate to stop. hard one time while driving...slowly to an almost manual feeling bottom (not the floor but close.

 

[Sixpactogo]

If it was an original front disc brake car, it should have had the dual ballast booster. Got any pictures to verify?
Beautiful car by the way!