2001 Toyota Tacoma Prerunner - Project Venture Toy - Tech

The original 1 3/16-inch bore Toyota master cylinder and its booster are pictured at the top. Below them is a 1 1/8-inch bore Chevy master of the type that was used on many late 1980s to early 1990s pickups. Next to it is a dual Toyota booster that was used on T100s and late 1990s 4Runners. This model booster provides greater assist as compared to our stock unit.

The new booster was meant to mate to a four-bolt master cylinder. This is where we used the aluminum adapter. We had to adjust the pushrod (shown here) to mate to the Chevy master while still leaving a small bit of endplay. Additionally, we had to shorten the brake pedal rod on the other side of the booster and add some more thread distance with a die to reuse the stock pedal linkage and get it mated to our brake pedal.

Here you can see the Chevy master cylinder mated to the Toyota dual booster and mounted to the firewall. The installation came out clean and fits the available space well. For the front circuit, we ran all SAE plumbing and hoses down to a tee on the front axle where it split off to each front caliper. For the rear circuit, we used SAE fittings and hard line down to the original metric fitting on the frame rail that connects to the brake line running to the rear of the truck. We cut the lower SAE fitting off our hard line and re-flared it, using a metric male to connect to the original Toyota fitting.

For front axle brake lines we opted to go with complete flex hoses and eliminate any hard steel lines. Crown Performance builds stainless braid brake lines in standard and custom end configurations. We were able to order our lines to the exact length and with the specific end fittings we needed.

Normally, you wouldn't want to plumb excessive distances with a rubber or most flex hoses as they tend to bulge a bit under braking pressure, and the longer the run the greater the loss of pressure due to this bulging. However, the Kevlar encased Crown hoses keep this expansion to a minimum so longer hose runs do not become a problem. Crown hoses are also DOT approved so we're confident in their use on the highway.

You may recall our axles use half-ton Chevy calipers, which accept a 7/16-inch banjo bolt and fitting. We had Crown build our hoses with a banjo block on one end and a -3AN female on the other. The driver and passenger hoses meet at a -3AN tee on the front axle pumpkin and a third hose goes from the tee up to our proportioning valve near the lower firewall. Since Crown offers a variety of hose end styles, we were able to plumb everything together without the addition of extra adapter pieces.