Aftermarket Koyo Radiator Cap Fitment - OEM Cap Compatibility

Coolingbeginner✓ Community Verified

Problem

Aftermarket Koyo radiators do not come with a radiator cap, and the owner needed to find a compatible cap without paying premium prices for brand-specific Koyo/HKS/GReddy caps.

No radiator cap included with aftermarket Koyo radiatorUncertainty about which generic or OEM cap fits

Root Cause

Aftermarket radiators like Koyo use the same filler neck dimensions as the OEM Toyota radiator, so standard OEM or equivalent caps fit without issue.

Confidence

Moderate confidence — Multiple community members agreed on this solution

View Original Thread →Posted May 2023 on SupraForums.com