Stop Leak
FailThe top 5 brands take 100% of clicks, so Stop Leak is a Fail.
- Flapen Score
- 43 / 100Ranks 5,360 of 7,287 Automotive niches · −6 vs the category median of 4943
- Market size
- $284K/yr187K searches / yr
- 90-day growth
- -12.2%search demand this quarter
- Competition
- 86%top-5 click share · 5 brands · 74 sellers
Flapen Score
Stop Leak against its category
The dotted line is the Automotive average. Past it, Stop Leak is stronger. Inside it, weaker.
Market
The Stop Leak market on Amazon at a glance
Shoppers on Amazon United States searched for Stop Leak 187K times last year and spent an estimated $284K. All 5 brands take every click. Demand peaks in Aug. Flapen scores it 43 out of 100, a Fail.
01 · Demand
An estimated 13.6% of those searches ended in a purchase.
Shoppers searched for this 187K times in the last 12 months. That counts every search on Amazon United States for this niche's terms. An estimated 13.6% of those searches ended in a purchase. Searches in the last 90 days moved -12.2% against the 90 days before. Searches, conversion and average price together put the market at an estimated $284K a year.
- Searches, last 12 months
- 187K
- Growth, 90 days vs prior 90
- -12.2%
- Conversion, latest week
- 13.6%
- Market size, estimated
- $284Ka year
- Peak month
- August1.7× the quietest month
- Top search term
- radiator stop leak45K searches a year
02 · Price
A sale here is worth $11.23.
Listings sell for $11.23 on average, from $4.10 to $22.51. Amazon reports units sold in ranges. This niche sold 20K to 25K a year. The average listing sells 1,500 to 2,000 of them. At $11.23 that is $17K to $22K a year per listing.
- Average price
- $11.23under the $15 to $100 sweet spot
- Price range
- $4.10–$22.51
- Amazon United States median price
- $24.38across 115,062 niches
- Units sold a year
- 20K–25K
- Units per listing a year
- 1,500–2,000
- Revenue per listing a year
- $17K–$22K
- Returns
- 1.5%of orders · Amazon United States median 2.1%
03 · Entry bar
The bar here is ads and reviews.
100% of listings pay for placement with sponsored ads. 100% ship with Prime. On an average day, 0.0% of listings are out of stock. The average listing ranks #8 within Fillers, Adhesives & Sealants. It carries 2,752 reviews at 4.37 stars, so a new listing needs social proof before a better product.
- Sponsored listings
- 100%
- Prime listings
- 100%
- Out of stock, average day
- 0.0%
- Average rank
- #8in Fillers, Adhesives & Sealants
- Average rating
- 4.37 starsAmazon United States average 4.42 stars
- Average reviews
- 2,752per listing
- Listings tracked
- 9
04 · Newcomers
Brands here are established.
The brands on the shelf have sold for 96 months on average, so the names here are established.
- Launched, last 12 months
- 0
- Successful launches
- 0Amazon's first-year sales bar
- Average brand age
- 96 months
Products
Top Stop Leak products & what they sell for
The products selling here, as shoppers see them on Amazon. Shelf share and sales are our estimates.
Prices and ratings read from Amazon on Jul 8, 2026. The live listing can differ.
Top sellers
by estimated 90-day click share
K-Seal ST5501 Multi-Purpose One Step Coolant Leak Repair 8oz Pour and Go Mixes with All Antifreeze No Flushing Required
- Price
- $12.56
- Rating
- 4.3/5
- Reviews
- 13,323
- Age
- 17y ago

Bars Leaks Cooling System Radiator Stop Leak 16.9 oz.
- Price
- $7.77
- Rating
- 4.3/5
- Reviews
- 3,820
- Age
- 17y ago

K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Coolant Leak Repair 16 oz Pour and Go Mixes with All Antifreeze No Flushing Required
- Price
- $20.27
- Rating
- 4.4/5
- Reviews
- 1,665
- Age
- 17y ago

K-Seal ST3501 Pour & Go Head Gasket Sealer 16 oz Repairs Blown Head Gaskets Cracked Heads & Engine Blocks
- Price
- $22.51
- Rating
- 4.1/5
- Reviews
- 2,109
- Age
- 11y ago

Bars Leaks 1109 Liquid Copper Block Seal Intake and Radiator Stop Leak 18 oz. | One Step Safe for All Cooling Systems
- Price
- $8.07
- Rating
- 4.3/5
- Reviews
- 1,506
- Age
- 18y ago
Trending
estimated 90-day click momentum
K-Seal ST5501 Multi-Purpose One Step Coolant Leak Repair 8oz Pour and Go Mixes with All Antifreeze No Flushing Required
- Price
- $12.56
- Rating
- 4.3/5
- Reviews
- 13,323
- Age
- 17y ago

Liqui Moly Radiator Stop Leak | 250 ml | Cooler additive | SKU: 20132
- Price
- $12.75
- Rating
- 4.4/5
- Reviews
- 655
- Age
- 8y ago

Bars Leaks Cooling System Radiator Stop Leak 16.9 oz.
- Price
- $7.77
- Rating
- 4.3/5
- Reviews
- 3,820
- Age
- 17y ago

Visbella Radiator Stop Leak Sealer Conditioner Radiator Repair Kit Car Heater Core Freeze Plugs Cooling System & Radiator Repair (Tube pcs 1)
- Price
- $8.06
- Rating
- 4.5/5
- Reviews
- 154
- Age
- 2y ago

K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Coolant Leak Repair 16 oz Pour and Go Mixes with All Antifreeze No Flushing Required
- Price
- $20.27
- Rating
- 4.4/5
- Reviews
- 1,665
- Age
- 17y ago
Newest
by launch date
Visbella Radiator Stop Leak Sealer Conditioner Radiator Repair Kit Car Heater Core Freeze Plugs Cooling System & Radiator Repair (Tube pcs 1)
- Price
- $8.06
- Rating
- 4.5/5
- Reviews
- 154
- Age
- 2y ago

Bars Leaks Radiator Stop Leak 11 oz
- Price
- $4.99
- Rating
- 4.4/5
- Reviews
- 232
- Age
- 2y ago

Liqui Moly Radiator Stop Leak | 250 ml | Cooler additive | SKU: 20132
- Price
- $12.75
- Rating
- 4.4/5
- Reviews
- 655
- Age
- 8y ago

K-Seal ST3501 Pour & Go Head Gasket Sealer 16 oz Repairs Blown Head Gaskets Cracked Heads & Engine Blocks
- Price
- $22.51
- Rating
- 4.1/5
- Reviews
- 2,109
- Age
- 11y ago

K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Coolant Leak Repair 16 oz Pour and Go Mixes with All Antifreeze No Flushing Required
- Price
- $20.27
- Rating
- 4.4/5
- Reviews
- 1,665
- Age
- 17y ago
Competition
Competition: brands, sellers & click share
The top 5 products take an estimated 86% of clicks. A locked shelf that new listings rarely crack.
Brands
5 falling
Sellers
74
Est. top-5 brand share
100%
Top 20: 100%
Est. top-5 click share
86%
Top 20: 100%
Open market
0%
- K-Seal64%
- Bar's Leaks25%
- Liqui Moly5%
- Visbella4%
- ACDelco2%
Demand
Stop Leak search demand
Weekly searches over the year, seasonality beneath. Pick a range.
Peak months: Aug · busiest ÷ quietest = 1.7×
Search terms
Top Stop Leak search terms shoppers use
The exact words shoppers type, with estimated yearly volume, growth, and conversion.
- radiator stop leak45K/yr
- k seal28K/yr
- coolant leak sealer11K/yr
- k seal permanent coolant leak repair10K/yr
- coolant stop leak8K/yr
- bars leak8K/yr
- radiator leak sealer9K/yr
- radiator stop leak sealant heavy duty7K/yr
- stop leak radiator treatment7K/yr
- k-seal coolant leak repair7K/yr
Reviews and returns
What reviews say buyers love and hate about Stop Leak
We read the reviews and the return reasons for every product selling here.
“Had a leak”
Every topic
Every topic buyers talk about, one row each.
Red shows the share of negative reviews and green the share of positive reviews, biggest topic first. Open a row to read what they wrote.
17 topics
Keep looking
Related niches
Niches in the same category that score near this one. Research these next.
Best Flapen score
The highest-scoring niches we track right now, across every category.
FAQ
Common Stop Leak questions
Answered from the same tracked data.
Figures on this page are estimates modeled from public Amazon pages and third-party keyword data. Amazon does not supply them, and no connected seller's data is used. How we handle Amazon data









