B Body Mopar B Body Mopar forum

Disc brake swap question

65coronet440
07-18-2011, 08:18 PM
So i recently did my disc brake swap and all went well... had some issues with the toe on the alignment... but got it pretty close......

But i was wondering, if i have the new disc brakes, should the pedal be super stiff... its stiff from the get go... I dont know what to expect with the vacume set ups on these old mopars... it wasn't like this with the drum brakes.....as it shouldn't be.... it just feels like it should be softer like cars now a days.....

can someone shead some light on this

ga66mopar
07-19-2011, 06:13 AM
I did the disk brake conversion with powerbrakes on my 66 and the pedal is not stiff. If it has a powerbrake booster the pedal shouldn't be hard.

65coronet440
07-19-2011, 07:45 PM
well what would make a pedal hard?

i got a new booster and master!

Dodge33
07-19-2011, 08:04 PM
Do'es the car have new or rebuilt caliper's on it? In my experience especially with rebuilt caliper's, some of the cheaper line's at auto part's store's they have been kind of sticky, stuck, kind of thing to which the pedal pushed a lttle hard. JMHO. I have also seen the brake split block seem set-up too which wiill make the pedal seem hard or push funny. Do you know if the brake split block was ever open to the elements of the weather........ could have something to do with it IMO. Good Luck

GTXKen
07-20-2011, 07:29 AM
When you did the swap did you change masters and the proportioning valve? The change to disks means a larger piston which in turn requuires the master and proportioning valve change.

65coronet440
07-20-2011, 08:56 AM
The car has never been open to the elements. always been garaged. when i did the swap the kit came with all new(not remanufactored) rotors, calipers, spindles ect. and then i also bought a new master and booster.. i replaced the front brake lines because i cound not get off the old ones. i did not replace the propotioning valve though... however i did mistakenly swap the front and rear brake lines at the master cylinder and did a complete bleed, until i realised that i did it incorrectly and swapped it back correctly.... did i mess up the proportioning valve? or did a mess up something bigger

GTXKen
07-20-2011, 09:06 AM
The proportioning valve needs to be swapped, you didn't mess anything up it just isnt right for your setup anymore. A 4 wheel drum car uses a different valve than a disk/drum car than a 4 wheel disk car. Very suprising that whomever sold you the kit would not tell you that. Make that change first.

Dodge33
07-20-2011, 09:07 AM
you need to change the drum brake split block to one off a disc brake car,that is what is making the pedal stiff. hope this helps, as far as hooking the line's up wrong that is not going to affect or hurt anything.

65coronet440
07-20-2011, 12:57 PM
Thanks for clearing that up, i thought that i ruined the car...lol

so any ideas where to look for the proportioning valve... and the split block? ive never heard of the split block before...where is it located?

65coronet440
07-20-2011, 02:30 PM
Thanks for clearing that up, i thought that i ruined the car...lol

so any ideas where to look for the proportioning valve... and the split block? ive never heard of the split block before...where is it located?


Ok, so i called summit racing and they suggested a proportioning valve that would work for my set up...will be here tomorrow...thanks for the help everyone!!!