K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Permanent Coolant Leak Repair, 16 oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required
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K-Seal ST5516 Heavy-Duty Multi-Purpose One Step Permanent Coolant Leak Repair, 16 oz, Pour and Go, Mixes with All Antifreeze, No Flushing Required

4.3/5
Product ID: 8435813
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🌍Compatible with all antifreeze
🔧Heavy-duty performance
⏱️Fixes leaks in minutes

Description

🚗 Fix it fast, drive it proud!

  • ONE STEP APPLICATION - Just shake, pour, and go—engineered for ease.
  • COST EFFECTIVE REPAIR - Enhance your vehicle's performance without breaking the bank.
  • HEAVY DUTY RELIABILITY - Designed for large engines and industrial use.
  • PROFESSIONAL GRADE TRUST - Endorsed by mechanics and independently verified.
  • QUICK PERMANENT SOLUTION - Seal leaks in minutes with no flushing required.

K-Seal ST5516 is a heavy-duty, one-step coolant leak repair solution that permanently seals leaks in various engine components. Designed for ease of use, it requires no draining or flushing, making it ideal for both commercial and agricultural vehicles. Trusted by professionals, this non-corrosive formula enhances engine reliability and performance.

Specifications

ManufacturerSolv-Tec
BrandK-Seal
ModelST5516HD
Item Weight1.17 pounds
Product Dimensions5.9 x 4.1 x 1.9 inches
Item model numberST5516HD
Is Discontinued By ManufacturerNo
Manufacturer Part NumberST5516

Have a Question? See What Others Asked

Does it work on potentially warped heads
how much do i need to pour in a diesel 1 ton cummins
Will this work with aluminum heads?
Tried using alumaseal, which isn't working. will i need to flush the system before using the k-seal?

Reviews

4.3

All from verified purchases

C**B

This liquid works, Ford can eat the D!

After reading many reviews, this product was used on several f250's like mine with similar water leaks. Mind blown that it fixed my leak in minutes when for days and many new Ford parts purchased, 20 bucks fixed it! Get it works! Oh and Ford make products old school and straight forward repair instead of tight spaces, and multiple clips and hoses!

S**N

It works for small cars too

Used it on my 2004 malibu.I used half a bottle.Works great !!! I was shocked.The Car had water squirting out of the tail pipe every time you revved the motor...like alot.I shook it up and poured have into an empty water bottle then poured it into the hose that goes to the overflow. I didn't drain the antifreeze.It worked so fast I didn't belive it...But the car only has 78,000 or so miles so it shouldn't have had any problems that soon.So maybe the hole was small.Either way I'm super happy.3 weeks later it's still going.Oh yeah. And 3 weeks ago I failed my visual inspection while getting it smogged.I'll update ones I take it back.

D**`

Worked great on a 15 liter Cummins ISX Radiator leak

Had a decent radiator drip on my RV. It is a huge radiator, 4 feet wide. I was going to get the radiator removed and fixed at a radiator repair place but it was so large I couldn't get it out of the bottom of the RV without jacking it up 2 feet.I was skeptical to try this K-Seal but the advertising said it could handle the heavy duty capacity of my 15 liter Cummins ISX diesel size, so I tried it.Within 25 minutes the leak was gone, pretty amazing. I let it run for an hour just to be sure. I will be driving it to a race soon and make sure it stays fixed.Happy that I didn't have to remove radiator, saved myself 10 hours of labor and hundreds of dollars to repair.

D**S

N/a

Worked great

E**A

Seems to be working

So far so good

K**H

WILL RUIN YOUR ENGINE!!!

it doesn't work, waste of money EDIT: DO NOT BUY THIS PRODUCT!!! IT CLOGS UP YOUR ENGINE AND WILL CAUSE IT TO BLOW UP!!!

M**A

This stuff WORKS

The stuff really works. My F350 powerstroke had a leaking water pump after 266000 miles. It was leaking like a sieve. Poured the K-Seal in, leak slowed up within a minute, totally stopped after 5. I totally impressed with this product. I never write reviews, only if the product works better than expected or if the product is junk. 5 stars for K-Seal.

M**O

K Seal did fix intake manifold gasket leak.

The media could not be loaded. So I have a 2005 Chrysler Pacifica, with about 206,000 miles. For the last 2 years I've been fighting this leak through the intake manifold gasket, where I would have to put in about of quart of coolant every 3 days. I've been working on cars all my life so I know how hard it is to change a head gasket or even a intake manifold gasket. Throughout the two years I've been using J-B weld aluminum extreme heat which were only suppressed the leak for about 2 months at a time. After doing a little bit of research I came across this product. Started watching videos and reading testimonials. I was like what the heck let me try it. The leak would occur usually about three to five minutes after I start my car. I added a little bit more coolant, and started my car. I followed the instructions shaking the bottle for 30 seconds vigorously and proceeded to pour the whole bottle into the reservoir tank. My car was really low on coolant so when I added the k seal it went directly from the reservoir into the block. I added a little more coolant to top the reservoir tank off and and place the cap back on the reservoir. At this point my car had already been running for about 5 minutes and what do you know not a trace of coolant was leaking. Like I said before this been happening for 2 years so I know that the coolant should have been leaking by now. So I let the car run for 30 minutes. I turned on the heat full blast just so it wouldn't get clogged into the coils of the heater core. Usually about 30 minutes of running my car the coolant would have been pouring out of the gasket in between the intake manifold and the head. There was no leak at all. After close inspection the area was bone dry. I have never witnessed a product that can fit fix a gasket leak like this one. It literally save me about $1,500 in costly repairs, actually would have been less because I would have been fixing it myself ,but still save me about 5 to 8 hours of labor. So my review for this product is definitely 5 stars and it definitely worked in my situation. I will update this in about 30 days. See the video for yourself.UPDATE: As of today, (May 19th). the leak is still sealed. It's been about 45 days and the seal is still going strong!

Common Questions

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Anita G.

Good experience, but the tracking updates could be better.

2 months ago

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The customer service exceeded my expectations. Perfect for buying products you can't find elsewhere.

1 week ago

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Trustpilot

TrustScore 4.5 | 7,300+ reviews

Ali H.

Fast shipping and excellent packaging. The Leatherman tool feels very premium and sturdy.

1 day ago

Anita G.

Good experience, but the tracking updates could be better.

2 months ago

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