[Sir-x-Loin]

Hey guys,
As the title states I have been having brake issues.

For some backround, I bought a complete suspension and brake upgrade package from Zigs Street Rods. The Kit came with a Mustang 2 front end with GM Metric calipers. I am pretty sure the rotors are 12 inches. The upgraded dual M/C is unknown. I think it is a GM unit. It has a booster. The rear end is a ford 9" with the stock drums.

I have Never been satisfied with the brakes. I thought I wasnt getting enough vaccum for the booster to work. I installed a vac can with no improvement.

I have a Hurst roll control unit installed. The unit would not hold my truck still. I wouldnt say I have great traction either.

I have a proportioning valve installed and have messed with it and still no results.

I am at my wits end with the issue. I really dont want to shell out a bunch of money I dont have to make this thing safe. It SHOULD be stopping great.

[57halfton]

I've kind'a been there done that with my 57 pickup. First you mentioned GM metric calipers, thats what I had on my Mustang II front end but the rotors (discs) were 10 1/2 in diameter. I upgraded to 11 inch rotors and earlier style larger calipers, late 60's early 70's GM calipers and my brakes work about 40% better (work good now). Also your power booster is probably a small diameter one about 8 inch or so, they really don't work that well because of the compact size. I don't have a power booster. Check with Ralph at ECI ,that where I got my 11 inch brake kit to fit Mustang II spindles


http://ecihotrodbrakes.com/

[Sir-x-Loin]

I Used to lived in the Hartford, CT area and remember that shop. I have a feeling that if anyone can find my weak link it is them. Thanks for the suggestion. I'll give them a call and see which direction would be a good starting place.

I'd really like to see your set up. I have had my 57 since 98 and have it just above "rattletrap" stage now. Thanks again.
-Brian

[OLNOLAN]

Hey Sir, Not sure if you are using underfloor or firewall mounted M/C, but the pedal ratios are different between manual and power brakes. You maybe experiencing this problem. Heres a link to one company that includes a pedal ratio adapter for use with their power conversion kits.

http://nolimit.net/Instructions/PBC55.pdf

olnolan

[57halfton]

lNice save Olnolan, I didn't think about that. My MC is under the floor with a stock pedal and adapter for a 67 Mustang power disc 1 inch bore MC.
Gene

[cobalt327]

Originally Posted by 57halfton

lNice save Olnolan, I didn't think about that. My MC is under the floor with a stock pedal and adapter for a 67 Mustang power disc 1 inch bore MC.
Gene

That type system will often use residual pressure valving if the MC is lower than the calipers/slaves to prevent fluid run-back.

[OLNOLAN]

Originally Posted by 57halfton

lNice save Olnolan, I didn't think about that. My MC is under the floor with a stock pedal and adapter for a 67 Mustang power disc 1 inch bore MC.
Gene

Hey Gene, I think that you are the Guru having actually done these conversions before. I respect your opinion very much.

I have researched the hell out of this stuff while trying to save up the money to finish mine. Because of the nature of my '57 build I can't do it incrementally. I have to buy all the suspension, steering and braking system components and do it all at one time.

In SIR'S case, Maybe he should back up and evaluate the entire brake system. As COBALT pointed out, residual valves are required on under floor systems. Pedal ratio, residual valves, master/booster sizing, rear proportioning valve, etc. all need to work as a system to provide adequate braking power. For instance, in researching I found that some folks using the 7" or 8" boosters were not getting enough power assist. There are sources for small boosters that are double diaphragm (I think they were Mustang units)that provided plenty boost in a compact case.

I'm hoping to install a well thought out system, to avoid rework and buying the parts twice. It seems that some of the kits available do not provide an optimum system its just a little better than the stock brakes. If I'm going to shuck out big cash to do a full brake upgrade, I want brakes that will sling me into the windshield if I get on the pedal too hard. Nolan

Heres some links from my favorites, seems that alot of the really good stuff is in the back of the catalog;

http://www.totalcostinvolved.com/

http://www.brotherstrucks.com/

http://www.golden-state-parts.com/new_parts.htm

http://www.detroitspeed.com/

http://www.heidts.com/

http://www.zigsstreetrods.com/Pages/trucks.html

http://www.charlotterod.com/

http://www.ecklerstrucks.com/

http://www.mpbrakes.com/

http://www.classicperform.com/4754chevtrk.html

http://www.speedwaymotors.com/

http://www.posiesrodsandcustoms.com/

http://ecihotrodbrakes.com/index.html

http://www.mpbrakes.com/uploads/cont...%20catalog.pdf

http://www.wilwood.com/

http://www.lmctruck.com/

http://nolimit.net/departments.asp?dept=1032

http://www.southernrods.com/categories/brakes/

http://streetrodengineering.com/Prod...ekitsparts.htm