Author Topic: Wilwood 7/8" master question  (Read 2650 times)

Offline gregm784

  • Sr. Member
  • ****
  • Posts: 379
    • View Profile
    • Means Racing
  • Your Engine: 387 Dart/Brodix
  • Your Track: Famoso Raceway
  • Your Vehicle: 1997 Stirling 200" FED
Wilwood 7/8" master question
« on: December 13, 2016, 09:24:44 PM »
Is preloading the piston in a master a no no?  I'm trying to get rid of some handle pull.  My lever ratio is 8.5:1, i'd like to shorten up the pull a little.  what is a favorable lever ratio?  
El Dorado County, CA

Offline BK

  • Sr. Member
  • ****
  • Posts: 275
    • View Profile
  • Your Best Time: 8.45 / 5.30
  • Your Track: Empire Dagway
  • Your Vehicle: Late 70's FED
Re: Wilwood 7/8" master question
« Reply #1 on: December 14, 2016, 04:13:31 AM » It doesn't address the preload question though. A larger bore should shorten the stroke if you have enough leverage.


  • Guest
Re: Wilwood 7/8" master question
« Reply #2 on: December 14, 2016, 08:29:13 AM »
Piston must be fully retracted in order for the bore to receive fluid,
You could put an adj stop on the handle itself to take up play between the push-rod and piston if there is any there.
 Check your RPV, could be old and not holding the pucks out against the rotors
 Check the rotors for runout, could be kicking the pads back into the calipers making the travel longer to fill the gap.
 Why do you need that presice of a feel?? or is it that you cant pull it back far enough the way you are sitting in the car??  Raise the pivot point to lengthen the arm to increase throw on the bottom and will reduce throw at the top. If the pivot is on the bottom then raise (within limits) the push rod on the handle. This limits you in bleeding(drop the push rod down to bleed) but since the rod does not move that much when normaly brakeing, a small amount of angle is aceptable

Offline jeff/21

  • Full Member
  • ***
  • Posts: 186
    • View Profile
  • Your Best Time: 8.24
  • Your Track: any with-in a 6hr radius
  • Your Vehicle: fed
Re: Wilwood 7/8" master question
« Reply #3 on: December 14, 2016, 04:33:06 PM »
Is your master cylinder mounted lower than the brake cylinder or caliper if so you will need a residual valve to stop the fluid draining back into the master and you should not preload the master.

check the site BK suggested

Offline gordon

  • Newbie
  • *
  • Posts: 16
    • View Profile
  • Your Track: Sacramento
  • Your Vehicle: FED
Re: Wilwood 7/8" master question
« Reply #4 on: December 17, 2016, 09:52:03 AM »
If you can , run as much of your brake line using solid line not flex.  Gives better feel and usually lessens required travel.