Mopar Muscle Association UK

As my 70's Charger is a 500 model it did not come with a break servo and the previous owner has fitted a pair of willood calipers and uprated discs on the front but without a servo the breaks are still a bit crap so im thinking of fitting a servo so what all will i need to convert it and where is the best place to pick it all up?

Before you go the servo route are you certain that the master cylinder is correct for the front brake upgrade? I would have thought that with Wilwood brakes fitted it should stop fairly well, just with a little more brake pedal pressure necessary. Are we talking spongey brakes here or something different?

Gareth wrote:Before you go the servo route are you certain that the master cylinder is correct for the front brake upgrade? I would have thought that with Wilwood brakes fitted it should stop fairly well, just with a little more brake pedal pressure necessary. Are we talking spongey brakes here or something different?

Good point I had manual brakes on mine ( if that's the word) with Discs up front. Motor stopped fine also check your rear brakes maybe to see what condition they are in..it all helps..

Yea i will give it a full check over.

to explain what they feel like now i would say woody if you know what i mean? so they slow you up but if you needed to stop quick then you need to apply loads of pressure on the peddle almost both feet!

The bore of the master cylinder affects the amount of pedal pressure required. A smaller bore would require less pressure but would also result in a longer pedal travel. I'm guessing that you have a standard type master cylinder and not a Wilwood item? If so it's probably the original unit and stands a good chance of being mismatched with your updated brake setup.

JinxJay has just posted a solution for a very similar sounding issue........

http://www.moparuk.com/forums/viewtopic ... 632#608632

Gareth wrote:JinxJay has just posted a solution for a very similar sounding issue........

http://www.moparuk.com/forums/viewtopic ... 632#608632

Great thanks, that looks like the solution for me

as Gareth said, i've just done mine,

if you want to keep with manual brakes I've a disc ? drum master cylinder only about 18 months old you can have,

the brakes might also feel odd if the bias valve was not replaced with one to suit the brake set up you have,

but from my experience discs are much better with a servo, if you want I can dig out the details of the company I got mine from,

JinxJay wrote:as Gareth said, i've just done mine,

if you want to keep with manual brakes I've a disc ? drum master cylinder only about 18 months old you can have,

the brakes might also feel odd if the bias valve was not replaced with one to suit the brake set up you have,

but from my experience discs are much better with a servo, if you want I can dig out the details of the company I got mine from,

That would be great thanks for the help

need a disk master or the drum master with the residual pressure valve removed and close attention to the level of the fluid in the smaller reservoirs used for drum brakes

you probably need brake bias thingo unless you reduce the bore of the rear master cylinders (early 90s Dakota) or upgrade!! to smaller drums

disk brakes take much more line pressure to work than drums so you may find that the rears lock up well before the fronts reach a pressure that makes them work properly

and you need the rod into the master cylinder in the MANUAL position on the brake peddle arm if the brake peddle arm came from a boosted car.

most boosted/servo cars do not have it drilled

its basically further up the arm and a bit forward to give more leverage and more peddle travel.


if you use a mopar master you probably can't go wrong

however I know that the same symptoms were reported by people using SSB mopar upgrade kits and the issue there was the new stainless steel brakes master cylinder was ford internal dimensions in respect to bore

it was a big bore cylinder that made for short travel a "wooden" pads no feel to the brakes, especially when the actuating rod was in the position on the peddle for boosted brakes. probably works ok if you take their booster


Dave