radiator flush kit
Skip itSoft demand (-14.0% this quarter) — this niche doesn't clear our bar today.
Avg price
Incredible$25.85avg listing price — sweet spot $15–$100
Price range
Great$5.82–$93.11cheapest to priciest tracked listing — scored on the share inside $15–$100
Brand share
Good61%top-5 brand share — brands hold most of the demand
Returns
Good2.8%return rate — above 5% kills the launch gate
Competition
Good55%top-5 click share — leaders hold, buyers still browse
Quality gap
Good4.5★avg incumbent rating — lower means beatable quality
Review moat
Okay1,856.04avg incumbent reviews — the moat a new listing must climb
Conversion
Okay3.4%search→purchase rate — share of searches ending in a sale
Market size
Bad$82K$82K/yr · 94K searches
Growth
Bad-14.0%90-day search growth — must beat 0% to launch
According to Flapen's Amazon United States niche tracking, radiator flush kit is a $82K/yr Amazon United States market (94K searches/yr). The top 5 brands hold 61% of demand. Verdict: Skip it — 47/100.
Data updated Jul 12, 2026 · scored weekly · How we score niches
radiator flush kit market data
- Units sold / yr
- 3K–4K
- avg 100–250/product
- Revenue / yr
- $78K–$103K
- units × avg price
- Conversion rate
- 3.4%
- Avg BSR
- #645
- Page quality
- 0%
- Prime
- 100%
- Sponsored
- 78%
- Out of stock
- 0.0%
- Avg brand age
- 53 months
- Avg seller age
- 156 days
Competition & brand share
The top 5 products take 55% of clicks — established leaders, but buyers still shop beyond them.Brands
18 falling
Sellers
71
Top-5 brand share
61%
Top 20: 100%
Top-5 click share
55%
Top 20: 97%
Open market
34%
- Dorman17%
- EPAuto13%
- QUFYSK12%
- SEDY10%
- Prestone9%
- SMART JERRY5%
Demand & seasonality
Weekly Amazon search volume, last 104 weeks — -14.0% search growth over the last 90 days.No pronounced peak months · busiest ÷ quietest = 1.2×
Top radiator flush kit search terms
- radiator flush kit43K/yr
- coolant flush kit40K/yr
- cooling system flush kit8K/yr
- coolant system flush kit3K/yr
Top radiator flush kit products on Amazon
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
All 23 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
Dorman 47016 Coolant Service Kit Universal Fit
Dorman$9.284.4★288 rev
EPAuto Spill Proof Radiator Coolant Filling Funnel Kit
EPAuto$21.824.7★20,365 rev
QUFYSK Coolant Flush Gun Lever Action Heater Core Flush Kit Coolant Flush Kit for Automotive Coolant Flush Air and Water Radiator Flush Kit with Nozzles for 19-40mm Hoses
QUFYSK$29.814.7★27 rev
22-Piece No-Spill Coolant Filling Funnel Kit and Siphon Hose Pump Radiator Coolant Filling Spill-Proof Funnel Kit with Adapters Extensions PVC Hose Engine Oil Funnels Towel for Universal Vehicle
SEDY$23.374.4★419 rev
Prestone AS105 Total Cooling System Cleaner for Radiator Heater Core and Hoses 22 oz. 1 pack
Prestone$13.854.6★2,360 rev
Newest
by launch date
LURKA Coolant System Flush Gun Lever Action Heater Core Flush Kit with 3/4 & 1/2 Garden Hose Adapters/Shut-Off Valve Air & Water Combo Radiator Flusher Nozzles for 5 Sizes of Hoses (19-40mm)
LURKA$27.036 rev
QUFYSK Coolant Flush Gun Lever Action Heater Core Flush Kit Coolant Flush Kit for Automotive Coolant Flush Air and Water Radiator Flush Kit with Nozzles for 19-40mm Hoses
QUFYSK$29.8127 rev
Coolant Flush Gun heater core flush kit with Lever Action Air Includes 2 PCS 4 Garden Hoses with Multi-Size Nozzles for 19-40mm Hoses for Automotive Coolant System Flush Heater Core Cleaning
fatyehx$31.7119 rev
FIMXSD Coolant System Flush Gun Heater Core Flush Kit Radiator/Cooling System Flusher Tool Air & Water Combo Flushing Set Nozzles Fit 19-40 mm Hoses
FIMXSD$28.937 rev
Gulfmew Coolant System Flush Gun Lever Action Heater Core Flush Kit Radiator/Cooling System Flusher Air and Water Combo Flushing Set with Nozzles for 19-40 mm Hoses
Gulfmew$30.7995 rev
Trending
90-day click momentumLURKA Coolant System Flush Gun Lever Action Heater Core Flush Kit with 3/4 & 1/2 Garden Hose Adapters/Shut-Off Valve Air & Water Combo Radiator Flusher Nozzles for 5 Sizes of Hoses (19-40mm)
LURKA$27.034.5★
QUFYSK Coolant Flush Gun Lever Action Heater Core Flush Kit Coolant Flush Kit for Automotive Coolant Flush Air and Water Radiator Flush Kit with Nozzles for 19-40mm Hoses
QUFYSK$29.814.7★
BILITOOLS Coolant Funnel Kit Automotive Radiator Coolant Filling Tool
BILITOOLS$18.324.5★
BlueDevil Radiator Flush 32 oz | Deep Cleaning Coolant System Flush | Removes Rust Scale & Grime
BlueDevil Products$92.764.5★
Coolant Flush Gun heater core flush kit with Lever Action Air Includes 2 PCS 4 Garden Hoses with Multi-Size Nozzles for 19-40mm Hoses for Automotive Coolant System Flush Heater Core Cleaning
fatyehx$31.714.4★
What buyers say about radiator flush kit
What buyers praise and complain about, mined from review topics.What buyers love
“Excellent quality product”
“Pretty handy”
“worked well for my coolant change”
“Great deal”
“Working good”
“Did not leak”
“As advertised”
“Excellent fit”
“No messes”
“heat is now acceptable”
What buyers complain about
“Pieces are not compatible”
“Leaks from EVERYWHERE”
“Cheap quality”
“Not large enough”
“coolant was drain”
“weeks after today it overheat”
“if it does not work as planned”
“Directions are poor”
“it quickly became contaminated with rust also”
“it is made of very weak plastic”
Top return reasons
Common questions
- Is radiator flush kit profitable to sell on Amazon United States?
- The niche generates $82K/yr across 23 tracked products. 1 of 5 products launched in the last 360 days are still selling. 90-day search growth is -14.0%. Flapen's verdict: Skip it (47/100).
- How competitive is the radiator flush kit niche?
- 18 brands and 71 sellers compete. The top 5 products take 55% of clicks and top 5 brands hold 61% of demand.
- What do buyers complain about in radiator flush kit?
- Top complaints mined from reviews: Compatibility-Overall, Leak-Proof, Quality-Overall. The return rate is 2.8%.
- When does demand for radiator flush kit peak?
- Demand is steady year-round — the busiest month runs 1.2× the quietest.
- What does it cost to enter the radiator flush kit niche?
- Listings span $5.82–$93.11; the average listing price is $25.85 (sweet spot $15–$100). The average incumbent carries 1,856 reviews — the moat a new listing must climb.