Thermagasket Extreme Duty Head & Block Sealant
Thermagasket Extreme Duty Head & Block Sealant
Couldn't load pickup availability
The Thermagasket Guarantee
Follow the instructions. If it doesn't fix your leak, tell us within 30 days of delivery and we'll refund your purchase price. To make a claim, email Thermagasket@gmail.com with your order number, your email, vehicle year/make/engine, the symptom you had, the date you installed it, confirmation that you followed the instructions, and a photo or short description of the result. We'll review it promptly and reply by email. If we need you to send anything back, we'll tell you exactly what and arrange the return shipping with you.
Thermagasket Extreme Duty is a professional head gasket and block sealant for large gasoline and diesel engines with high capacity.
It is designed for cooling systems exceeding 7 gallons. This solution is designed to address heavy-duty engine leaks.
This two-part formula combines a 32 oz Extreme Duty Base Formula (Part A) with a 16 oz Catalyst (Part B) for maximum sealing power.
Together, they create a powerful sealing system. It is designed to repair blown head gaskets and leaks in cracked cylinder heads and blocks.
It is also designed to stop coolant loss and internal leaks, including combustion gas leaks into the cooling system.
Unlike temporary stop-leak products, this formula is built for demanding applications. It is ideal for heavy-duty trucks and commercial vehicles.
It works for diesel pickups, industrial equipment, and RVs.
Benefits of this Head Gasket and Block Sealant
Designed for engines with 7-gallon cooling system capacity or larger
Compatible with both gasoline and diesel engines
Professional-strength two-part sealing technology
Helps restore engine performance and cooling system integrity
Ideal for heavy-duty, commercial, towing, and high-load applications
Easy-to-follow application process
What's Included
32 oz Thermagasket Extreme Duty Formula (Part A)
16 oz Thermagasket Catalyst (Part B)
Will it work for my engine?
A sealant can't fix every engine failure. If your engine has major mechanical damage, such as a seized engine, a sealant is not the right fix. Not sure whether you need Extreme Duty or the standard Treatment Kit? Email us your vehicle, cooling system capacity and symptoms before you order.
If you need a diesel head gasket sealer or heavy-duty coolant leak repair, Thermagasket Extreme Duty is built for that job.
What Diesel & Heavy-Duty Owners Are Saying
"I called last year before Christmas when my 1995 Kenworth with a 460 HP Cummins Turbo overheated and blew a head gasket. I was about 800 miles from home!... As of August 1st I have clocked 90,000 miles on my truck since the repair without a hint of problems. The engine has about 350,000 miles and is running great. I keep a kit in my truck at all times just in case."
— Billy W, Omaha NE
"I have a d466 International diesel truck that had a huge amount of water getting in the oil... it just about quit steaming that first day and after the second treatment the engine has nothing coming out of the blowby tube but a little blowby."
— Mike Labriola
"Just wanted to say it worked in my 85 Ford Diesel, I have been plagued with this head gasket problem for years and in one application your product fixed it."
— Gary Meek
Share
