Keep proper pressure on your coolant, replaces any modern blue or black cooling cap
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms 10X Entries For Our 25th Anniversary Sweepstakes!
For use with late model expansion tank, requires minor modification of coolant system to work
Brand:
ES#:
4691207
Mfg#:
420121321
In Stock
ON SALE!
SAVE 14%
$34.99
This product was last offered at the strikethrough price on 05-02-2026
Keep proper pressure on your coolant, replaces any modern blue or black cooling cap
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms For use with late model expansion tank, requires minor modification of coolant system to work
Brand:
ES#:
2149010
Mfg#:
420121321
Ships in 2 Business Days
9% off MSRP
MSRP stands for Manufacturer's Suggested Retail Price. This is the suggested retail price provided by the manufacturer, supplier or seller.
$326.99
This product was last offered at the strikethrough price on 06-08-2026
Keep proper pressure in your coolant system
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms 10X Entries For Our 25th Anniversary Sweepstakes!
Brand:
ES#:
4858532
Mfg#:
2Q0121321A
In Stock
ON SALE!
SAVE 22%
$19.99
This product was last offered at the strikethrough price on 05-02-2026
Keep proper pressure in your coolant system
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms We Price Match - Give Us A Call or Chat! For use with late model expansion tank, requires minor modification of coolant system to work
Brand:
ES#:
3690266
Mfg#:
5Q0121321
Back Ordered
$18.99
This product was last offered at the strikethrough price on 04-02-2026
Keep proper pressure in your coolant system
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms We Price Match - Give Us A Call or Chat! For use with late model expansion tank, requires minor modification of coolant system to work
Coolant level sensor enclosed in tank, and includes cap!
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms We Price Match - Give Us A Call or Chat!
Keep proper pressure in your coolant system
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms 10X Entries For Our 25th Anniversary Sweepstakes!
For use with late model expansion tank, requires minor modification of coolant system to work
Brand:
ES#:
4818658
Mfg#:
5Q0121321
In Stock
ON SALE!
SAVE 24%
$15.99
This product was last offered at the strikethrough price on 05-02-2026
Keep proper pressure in your coolant system
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms We Price Match - Give Us A Call or Chat! For use with late model expansion tank, requires minor modification of coolant system to work
Keep proper pressure in your coolant system
affirm Starting At 0% APR - Subject To Eligibility. See Lending Terms For use with late model expansion tank, requires minor modification of coolant system to work
Brand:
ES#:
3672033
Mfg#:
3C0121321
Back Ordered
$5.99 USD
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Lifetime Replacement
More About Cooling Expansion Tank Parts
A common source of overheating problems is a broken or leaking coolant expansion tank. Replace it with an OEM coolant expansion tank or quality aftermarket expansion tank to prevent future woes.
Lifetime Replacement
