my motor isnt pulling enough vacuum so im going to install a strange master cylinder has anyone done this i have all the old stuff out any help is appreciated

 

I know motorcitymike has manual on his car, there is an adapter plate you`ll need I think, it may come with the strange kit, this one from profab does

 

thanks yeah that looks just like mine except for the alum. bracket im going to call them and see if i need it and if so ill order it thanks again

 

My MC adapter plate is made from a 3/4" thick piece of 6061 aluminum. It raises the master cylinder up some (can't recall exactly how much) because the fulcrum point on the brake pedal lever (where the MC pushrod attaches) has been raised also, to increase the leverage ratio, which increases the applied force to the master cylinder. An adjustable length pushrod with a heim joint end was also installed (like in the ProFab picture).

Ed Quay makes a kit also, but I'm not sure if includes a modified brake pedal lever, which is the key to making the conversion work effectively.

Here's a pic of mine:

 

Another angle:

 

how well does ur car stop with manual brakes? is it really hard to push the pedal to get the car to stop? also does the stock lines bolt right into the aftermarket MC? also how well do you think it would be for on the street like for some stop and go traffic?

 

Is this a track only car or street rig?

 

my car is mainly for the track but does anyone have a number for or web site for profab i just need that mounting plate ( hope this isnt a dumb question )also did you reuse the stock prop. set-up i want a line lock as well but i dont see the stock stuff at all???

thank again guys

 

Man thats so clean without the brake booster. How does it stop or is that a track car?

 

I'd be willing to guess its a track car since it has a blown 509ci in it pulling mid 9's

Either way though, I'm curious about the swap too. Never driven a car without power brakes...how bad would it be for daily driving? Is the MC the only thing that needs to be changed?

 

http://www.profabracing.homestead.com/

I think by the rules you can not run a line lock with a prop valve, the front brakes get 100% fluid and pressure anyhow and most run a adjustable wilwood valve to proportion the rears, check with stephen the moderator on the drag racing board to be sure though.

 

The car stops fine. You have to push on the pedal a little harder though. The actual pedal "feel" is much better. I also have a modified Wilwood front brake kit and Chrysler drum brakes in the rear, so the results of this conversion on your or anyone else's car may vary. You will have to use different line fittings for the Chrysler MC. I think it will work fine for street use, when properly set up. Years ago, it was a factory option from the auto manufacturers to have power brakes on cars - manual brakes were standard fare.

It quite frequently sees street use. It is plated, registered has mufflers and runs on 92 octane gas - same set-up as run down the track. It seems that a lot of people think that the manual brake arrangement is a "race only" type conversion. I have to stop my 3500# car from 145 mph in the distance of about an 1/8 mile - anybody who has ever run at Ubly knows about the short shut-down area there. I have no concerns with running manual brakes - street, strip, or otherwise.

The stock combination valve has been removed. I use a Wilwood adjustable prop valve. You don't see it because I have it mounted inside my car besides my driver's seat, where I can readily adjust it. Also, no residual pressure valves have been installed. If you look in the second picture, you can see my Hurst line lock mounted directly underneath the MC, just above the "frame" rail.

No. As I previously mentioned, the key to making the manual brake conversion work effectively is the leverage ratio must be changed. Many people don't do this, and then they wonder why their cars don't stop.

 

Well yeah, that's in that $100 ProFab kit though, right? That's what that bracket does? I meant like if there were any other parts of the braking system that need to be changed. That kit is all I'd need besides the adjustable prop valve that I have? I'm interested in this just to get rid of the big ugly brake booster, and to eliminate a possible problem in the future. I *may* be needing a new master cylinder anyways, and if I can do this conversion for $100, that'd be awesome.

 

The picture of the ProFab kit doesn't show anything that would include a modified pedal lever, or "bracket". You might want to inquire with them about this.



As far as other brake system components, I don't see any problem with using the existing factory pieces. You may have to rebalance your system an adjustable prop valve, but it looks like you're going to put one in anyway.