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Adjusting Clutch Master Cylinders

Following a new clutch installation there is nothing worse than experiencing slipping or release problems. Many times installers even begin to believe that the new clutch kit is defective. This is not correct, in most instances! The majority of the time a simple, quick adjustment will alleviate any problems. Most Japanese/Korean imports use an adjustable clutch master cylinder. When a new clutch kit is installed, the master cylinder (Figure 1) needs to be re-adjusted to work properly with this new kit and avoid release and slipping problems.

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By Brian Smith
Published:
Adjusting Clutch Master Cylinders Standard Issues Author: Brian Smith Subject Matter: Manual clutch Issue: Master-cylinder adjustment

Standard Issues

  • Author: Brian Smith
  • Subject Matter: Manual clutch
  • Issue: Master-cylinder adjustment

Following a new clutch installation there is nothing worse than experiencing slipping or release problems. Many times installers even begin to believe that the new clutch kit is defective. This is not correct, in most instances! The majority of the time a simple, quick adjustment will alleviate any problems. Most Japanese/Korean imports use an adjustable clutch master cylinder. When a new clutch kit is installed, the master cylinder (Figure 1) needs to be re-adjusted to work properly with this new kit and avoid release and slipping problems.

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The steps listed below demonstrate the proper way to adjust the master cylinder to avoid potential release problems with the new clutch:

Preventing no release

  1. Verify that hydraulic fluid is clean and that correct fluid was used.
  2. Locate the master cylinder pushrod that attaches to the clutch pedal.
  3. Using Figure 2 as reference, extend the pushrod to allow for more throw. After the rod has been extended, tighten the locking nut.
    Caution: DO NOT extend the rod out too far; this can block the compensating port in the master cylinder.

Preventing slipping

  1. Verify that hydraulic fluid is clean and that correct fluid was used.
  2. Locate the master cylinder pushrod that attaches to the clutch pedal.
  3. Using Figure 3 as reference, shorten the pushrod to allow for less throw. After the rod has been shortened, tighten the locking nut.

Note: In a slipping situation the rod is too long, causing the compensating port to be blocked off and not allowing fluid to return to the fluid reservoir.

Brian Smith is group leader of technical services for the LuK, FAG and INA product lines of Schaeffler Group USA Inc.

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