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<!-- google_ad_section_start -->Clutch Slave Cylinder swap, air bleeding, plus modification. [1,4 8V]<!-- google_ad_section_end -->
Clutch Slave Cylinder swap, air bleeding, plus modification. [1,4 8V]
How to replace and bleed the leaky hydraulic clutch actuator.
Published by GrandePunto PL
02-05-2021
Difficulty Level: 1

User Rated:Unrated

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Wink Clutch Slave cylinder modification to stop leaks.


This is clearly bad design. Master has a joint to allow rod cocking. Slave has none, so those "2 degrees allowance" may be too much (and it is in my car - or, maybe there is something else wrong, I don't know).
But. In power hydraulics world this is unacceptable at all, to tilt the piston and seals!
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How can it seal when you cock it? Who designed this?
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By the way, the boot should have a vent, check this when you buy a new cylinder...
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Now. Modifications. Idea 1 - not tested. Just add an o-ring (brake fluid compatible).
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Idea 2 - not tested. Stack the original seals (if you have 2 slaves).
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Idea 3 - not tested. Extra piston. Diameter is the same as brake cylinders = 20,6 (or 20,64 mm). But they take too much stroke. And metal can be too hard on the plastic body, bore.
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Idea 4 - done, testing (for almost a year now), works great. Custom made piston, plastic (PA - polyamide), plus seal from brake system (drum brake cylinders, from Punto 1). Of course, it takes a stroke space, but there is still plenty of it available for future wear compensation (but it must be checked periodically).
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Diameters are maximum. If anyone will ever make this mod, do it a bit smaller (all diameters smaller by 0,05-0,10 mm). It works great, but feels a bit on the tight side. Important thing is, it should push on the center of the original push rod, not crushing the seal.
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Animated GIF (click).
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There is a grease compatible with brake fluids. Use this during assembly.
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Thanks Davren thanked for this post
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