slave cylinder 100 configured to be used in a typical hydraulically actuated clutch disengagement system connected to a typical master cylinder fig6 discloses another embodiment of a novel adjustable slave cylinder 600 where the slave piston and threaded adjuster are designed to allow for minimum thickness as can best be seen in fig1 the novel adjustable slave cylinder 100 consists of a body 110 having an input port 111 that connects the adjustable slave cylinder 100 to an input hydraulic line 112 using a banjo bolt 113 with sealing crush washers 119 the adjustable slave cylinder 100 has a slave piston 114 with slave piston sealing o rings 115 the adjustable slave cylinder 100 has a threaded adjuster 116 with adjuster o ring seal 117 and an optional lock nut 118 fig2 discloses a cross section view of the novel adjustable slave cylinder 100 having a slave piston 114 which is configured to push against a throw out rod 201 the adjustable slave cylinder 100 has a body 110 having a threaded hole 202 for the threaded adjuster 116 to thread into the adjustable slave cylinder 100 has a body 110 having an o ring groove 203 which contains the adjuster o ring seal 117 to seal between the body 110 and the threaded adjuster 116 preventing hydraulic fluid from escaping the system and contaminants from entering the system the adjustable slave cylinder 100 has a body 110 containing a bore 204 which contains the slave piston 114 with slave piston sealing o rings 115 the slave piston sealing o rings 115 provide a seal.