This vented reservoir cap allows for expansion and contraction of fluid while maintaining a tight seal, and serves as a direct replacement for either AEM's 1.15-gallon or 5-gallon water/methanol reservoir.
Specifications:
- Vented design maintains a tight seal through fluid expansion/contraction
- Ridged design helps prevent slipping when removing or installing
- Direct replacement for AEM 1.15-gallon and 5-gallon reservoirs
- Wide cap opening for easy refills
- Part Number: 30-4508
FAQ
Which AEM tanks does this cap fit?
The 30-4508 cap is a direct replacement for both AEM's 1.15-gallon and 5-gallon water/methanol reservoirs.
Why is the cap vented?
The vent allows fluid inside the reservoir to expand and contract without breaking the tight seal.
Is the cap easy to grip when removing?
Yes, the ridged design is built to resist slipping when taking the cap on and off.

