Pour fluid into the reservoir to locate the leak, and if it’s small, you may be able to patch it, otherwise, replace the whole reservoir. Disconnect the battery’s negative cable and wait 90 seconds before stating to work, if your Toyota Tacoma is equipped with air bags.
Take out the reservoir by unbolting it from the upper radiator support. Then, lift the reservoir assembly from your Tacoma.
Slide the hose from the reservoir assembly. Then, remove the pump from the side of the reservoir by unhooking the wiring harness. Toss the seals.
Reattach the pump to the new reservoir by hooking the wiring harness to the side of the reservoir and putting the hose back on the reservoir.