Sorry for wrong name GreenDragginBu, I think I had Supe in the back of my mind, if i remember correctly, he had a similar problem.
My Manual brakes Are Horrible...Help
- Thread starter GreenDragginBu
- Start date
did we ever come up with any real solutions to the stiff pedal/poor manual braking dilema? I think lots of guys including me would like to know exactly which master cylinder is needed (part #) and if a different prop valve is needed.
Brian
Brian
I got that kit from Travis to. It took a lot of bleeding but I think I got it about as good as it's gonna get. I went searching the wilwood site and the only master I could find that looked anything like the one that came with the kit was this one:
There are two of them there that are identical and they both are 1 1/16 bore. I did find an interesting note though in the pdf instructions.
CALCULATING EFFECTIVE PISTON BORE AREA TO DETERMINE PLUMBING
To determine the effective piston bore area of any caliper, you must first calculate the area for each piston bore found on one side of the caliper. Use the formula " Area = ( bore x bore) x .785" for each piston bore size. Then, add the areas of all pistons on that one side of the caliper to determine the total effective piston bore area. Compare the difference between the front and rear calipers and attach the line from the primary outlet "A" to the calipers at the end of the vehicle with the greater total effective piston bore area.
Just thinking this out it would mean the rear brakes on the front outlet and the front brakes on the rear outlet. Which is the standard setup and how mine is setup now. But it's a good note in case that may not be how someone has theirs set up.
here is a web site with some useful info on how to select the right master cylinder bore diameter:
http://www.mikemulcahy.com/how_to_mstr_cyl.htm
Oh and there is this little pearl on those instructions to:
All drum brake applications require an inline 10 pound residual pressure valve.
So yeah I guess that residual valve needs to go in that is layin in the top of my tool chest. It's been a few years since I got this kit but I sure don't remember getting any instructions for the master with it.
There are two of them there that are identical and they both are 1 1/16 bore. I did find an interesting note though in the pdf instructions.
CALCULATING EFFECTIVE PISTON BORE AREA TO DETERMINE PLUMBING
To determine the effective piston bore area of any caliper, you must first calculate the area for each piston bore found on one side of the caliper. Use the formula " Area = ( bore x bore) x .785" for each piston bore size. Then, add the areas of all pistons on that one side of the caliper to determine the total effective piston bore area. Compare the difference between the front and rear calipers and attach the line from the primary outlet "A" to the calipers at the end of the vehicle with the greater total effective piston bore area.
Just thinking this out it would mean the rear brakes on the front outlet and the front brakes on the rear outlet. Which is the standard setup and how mine is setup now. But it's a good note in case that may not be how someone has theirs set up.
here is a web site with some useful info on how to select the right master cylinder bore diameter:
http://www.mikemulcahy.com/how_to_mstr_cyl.htm
Oh and there is this little pearl on those instructions to:
All drum brake applications require an inline 10 pound residual pressure valve.
So yeah I guess that residual valve needs to go in that is layin in the top of my tool chest. It's been a few years since I got this kit but I sure don't remember getting any instructions for the master with it.
Thats weird mine is spongy as heck . I used a 78 manual from auto zone and moved mine to top hole .
does anyone know off hand what the piston diameter is of the factory Gbody brake calipers and drum brake cylinders?
Generally, bore sizes bigger than 1" are only used for power brakes. If your bore is 1 1/16" your caliper pressure is going to be too low.
Tommy
Tommy
Holy old topic... I got through 2 or 3 posts before I realized how old it was :lol:
Yes, the bigger piston will cause a hard pedal. It doesn't provide enough pressure with "normal" pressure you typically put on the brake pedal.
Yes, the bigger piston will cause a hard pedal. It doesn't provide enough pressure with "normal" pressure you typically put on the brake pedal.
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