Adjusting the balance bar
Because of the caliper piston size and balance, the front
brakes require about twice as much fluid volume as the rear.
At rest, the outside link must be adjusted longer than the
inside one - roughly plus 3/8". This is to allow as much fluid to the
front brakes as possible before the balance bar bottoms out in the housing
(in the reversed angle that is shown at the right).
Note that the early cars used a different
configuration, with a pressed-in bearing and short spacers (no shims). The
longer spacer was used on the front brake master side. |
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The most compatible fluids are Castrol LMA and ATE type 400. Both are DOT
3 or 4. Don't use DOT 5 - it's silicone-based and may create problems with
seals. You will need about a pint of fluid total.
Since the front and rear brakes are separate systems, it doesn't matter which
you do first. While you can use a vacuum bleeder, it's not necessary.
I would do the flush this way:
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Open the right front bleeder and pump the brake pedal (slowly) until the
reservoir is almost dry. If you run it completely dry, you
will be punished.
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Fill the reservoir and pump the pedal again, until you're getting new fluid
from the right caliper. (Obviously) Don't ever let the reservoir go dry!
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Do the same process with the left front caliper.
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Repeat the sequence with the rear calipers, doing the right one first, then
the left.
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The feed for the clutch is midway up the reservoir, so don't let the level
fall below the feed hole when you flush the clutch. Have someone depress
the clutch while you open the bleeder. Close the bleeder before they release
the pedal. Repeat until the fluid is fresh.
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VW master cylinders
Used up to chassis #175, these cylinders are cast iron rather than aluminum of the Tilton units.
(2) VW 113 611 021C |
The VW master cylinder must be modified as follows:
- Remove the internal circlip that retains the piston.
- Remove the piston, spring and spring seat.
Create a way to bypass the internal residual pressure valve by:
- If there is a rubber plug in the spring seat, remove it or punch a small hole in the center.
- If there is a spring-loaded cone in the bottom of the spring seat, drill a small hole slightly off-center
- Thoroughly clean all components.
- Reassembly the cylinder
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Dragging Brakes (VW)
Brake drag is usually a result of a blocked return port in the master cylinder. This can be caused by serveral things:
- Misadjusted pedal return stop. Fix: Back off the adjuster, allowing more clearance.
- Rust in the master cylinder bore: Fix: Rebuild or replace the master cylinders. See above.
- Sticking balance bar - Fix: free up and lubricate
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