No matter the condition of your 1978 Bonneville, OPGI has the Master Cylinders & Boosters you need to boost performance and get you back on the road. We currently carry four Master Cylinders & Boosters to choose from for your 1978 Bonneville, and our Price Match Guaranteed prices range from as little as $25.99 up to $436.99. OPGI offers CPP plus one other trusted brands of Master Cylinders & Boosters for your 1978 Bonneville, to help you find quality parts you can rely on. With OPGI's 45-day return policy and thousands of customer reviews, you can shop with the utmost confidence. Enjoy parts delivered directly to your home, or visit our sunny Southern California Showroom & Warehouse to check out our Master Cylinders & Boosters in person.