Wilwood Brake & Clutch Pedal Description - Manual (Page 2)

WILWOOD PEDAL ASSEMBLY AND BALANCE BAR
Wilwood pedal assemblies and integrated balance bars have been designed specifically for racing applications. Properly
set-up, this assembly will allow for the precise adjustment of front-to-rear brake bias adjustment.
The advantages of an adjustable balance bar and dual master cylinders are:
1. Brake proportioning can be adjusted by use of different size master cylinder bores for front and rear brakes.
2. Front to rear brake balance can be fine tuned by adjusting the balance bar.
3. With two independent hydraulic systems, should one master cylinder fail, the other system may remain functional.
Master cylinder selection should correspond to your caliper piston displacement. Your Wilwood dealer, or Wilwood can
recommend specific master cylinders for your Wilwood calipers. Table 1 lists recommended master cylinder sizes for
Wilwood calipers.
Brake pedals should be mounted securely. Clutch pedal, brake pedal and master cylinder placement should be considered
when mounting the pedal assembly. Note that it is always desirable to keep the master cylinder reservoir level higher than
the horizontal plane of the calipers to prevent excessive fluid drain back which can result in double pumping of the pedal. If
this is not possible, a two pound residual pressure valve should be plumbed into the brake line at the exit of the master
cylinder to prevent fluid drain back (do not confuse the two pound valve with the ten pound version; the ten pound valve
is for use with drum brakes only!).
Brake pedals should be free to return when no pressure is being applied, allowing the master cylinder pushrod to return
to its undepressed position. In some cases, the master cylinder spring (internal) may not be strong enough to fully return
the pushrod; in this case an additional pedal return spring can be used. There are two important items for consideration:
1. The brake pedal should have an adjustable return stop on it when a strong pedal return spring is used. This
prevents the master cylinder from excessively banging the snap ring stop inside the master cylinder bore (visible
under the rubber boot). Adjust the stop so the pedal stops returning at the point when the master cylinder piston
retracts against the snap ring, Figure 1.
2. The master cylinder piston must fully retract. If the master cylinder piston is not allowed to fully retract when the brake
pedal is not applied, the primary inside seal will not return past the small pressure relief hole (visible within the master
cylinder reservoir on some master cylinders). This can cause excessive residual line pressure and contribute to brake
drag and an overheating condition, see Figure 1, Detail “A”.
CALIPER TYPE CALIPERS PER M.C. PISTON DIAMETER NO. OF PISTONS/CALIPER RECOMMENDED M.C. SIZE
GT / GT 6000
GN
SL / DL
SL / DL
SL
DLS
GM
GM
2
2
2
2
2
2
2
2
1.88" / 1.75"
1.75" / 1.38" / 1.38"
1.75"
1.38"
1.12"
1.75"
2.75"
2.38"
4
6
4
4
4
2
1
1
3/4" - 7/8"
7/8" - 1"
7/8" - 3/4"
7/8" - 3/4"
7/8" - 3/4"
7/8" - 3/4"
7/8" - 1"
7/8" - 1"
Table 1. Caliper piston displacement - master cylinder size
Page 2
Photographic Tip
We suggest you take digital photos of the brake system setup before and during the disassembly procedure. This will aid in the event
that something is not compatible with the new brake components and be a valuable tool to assist in the trouble-shooting process.