How do you adjust a hydraulic clutch

Readjust the hydraulic clutch - this is how it works

Even the greatest expert will not be able to adjust a hydraulic clutch, because the hydraulic clutch does that by itself. Some of the things that bothers you when you are coupling can still be changed.

Principle of the hydraulic clutch

  • By applying pressure to the clutch, you press hydraulic oil from a master cylinder into a slave cylinder. The hydraulic oil is fed into the system from an expansion tank. If the clutch wears out, a little more oil is simply taken from the expansion tank, the master and slave cylinders have different diameters. This allows the power transmission to be controlled. The automatic readjustment works in a similar way to the brake piston when the brake pads wear. The piston in the slave cylinder moves further and further out of the housing and the hydraulic oil flows in from the reservoir.
  • Most drivers who drive with a hydraulic clutch for the first time have the problem that they notice a very late grinding point. This is not a defect, hydraulic clutches are set this way, you have to get used to it.
  • The idea that a clutch has to be readjusted every few thousand kilometers cannot be gotten out of one's mind. A hydraulic clutch is designed in such a way that it always adjusts itself correctly. There is nothing to regulate or readjust. But you can change something about the pedal travel or the hardness.

Adjustment of pedal travel and hardness

  • The hydraulic clutch has a hydraulic system and such systems can always run into problems if air is trapped in it. Instead of distributing the pressure of the pedal in the system, the trapped air is compressed and the clutch does not work reliably and only disengages poorly when shifting. You need to bleed the clutch. There are instructions for this in the manual. In principle, put a transparent hose on the bleeding nipple and guide this hose into a suitable container to collect the liquid. Now you have to open the vent screw with a ring spanner (one turn is enough) and operate the coupling several times until no more bubbles can be seen in the hose. Of course, you have to refill hydraulic fluid in the reservoir.
  • The pedal travel is to be determined via rods, cables or exclusively via the master cylinder. Take a close look at the course of the coupling. Is there any part that looks "freshly broken" or cables that can be changed? If not, have the master cylinder replaced.
  • Changes in the master or slave cylinder can increase the pressure, i.e. the clutch becomes softer or harder. But this is more of a theoretical possibility, because you cannot simply change something on these parts. There may be different cylinder variants for your vehicle, but that is unlikely.

With all measures, remember that hydraulic oil is poisonous and must not be released into the environment. Since hydraulic clutches require little maintenance and there is nothing to readjust, it is usually better if you get used to the peculiarities of the pedal travel and, if in doubt, go to a workshop.

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