Precision Works K系列 加水頸升級件 用於K20上冷卻液外殼

Swapping out the stock plastic cap for this CNC-machined filler neck was a straightforward job, and I can already see the peace of mind it brings with the 16AN fitting. The machining is clean and the O-ring seals perfectly, no leaks on my K-swap so far.

Swapping my stock housing for this 16AN upgrade took maybe twenty minutes, and the threaded fitting seats so snugly I didn't even need extra sealant. Coolant temps have been steady on track days, and the extra port makes bleeding the system far less of a headache.

I’ve been running this 16AN filler neck on my K-swapped Civic for a few weeks now, and the machining is spot-on—no leaks or fitment issues. It’s a simple upgrade that makes burping the cooling system way less of a hassle.