they are non-adjustable units
That is true, but if there is sponginess in the pedal, there may be a leak in the SLAVE CYLINDER. The slave cylinder is not repairable and must be replaced as a whole unit. It is mounted to the drivers' side of the transmission. The unit is opearated when the clutch is pushed in. To check if the unit is low, check the resavoir that is under the hood next to the brake fluid/master cylinder. The cap on mine says to use DOT 3 brake fluid.