WARNING: This page is about a different car, the 2002 GMC Safari and 2002 Chevrolet Astro. However, it is still accessible from the selected car via links, so may be relevant.
Install the check valve (1) using a 3/8 inch diameter piece of tubing 100 mm (4 in) long to drive into the steering gear housing.
Fig 1: Installing Check Valve Using A 3/8" Diameter Piece Of Tubing