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0871 288 7125

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How to use Steel Seal 

Blown Head Gasket Repair in 3 Easy Steps...


Use Steel Seal to Fix a Blown Head Gasket

1. Make sure the engine is cold and remove the radiator cap. Pour Steel Seal directly into the radiator. Tighten the radiator cap back on. Ensure coolant is present before running the engine. If you have drained the coolant out, pour Steel Seal into the system and top up with coolant and move to step two.

2. Turn the heater and fan to maximum. Start the engine and run your vehicle up to temperature (please note this can take between 15-25 minutes depending on the condition of your vehicle). Once your vehicle reaches operating temperature run for 30 minutes. Turn off vehicle and allow to cool completely. Top up with antifreeze/water as necessary, replace radiator cap tightly.

NB. If you are introducing Steel Seal via an expansion tank please make sure that there is sufficient room for Steel Seal to go directly into the cooling system and that it does not just sit in expansion tank reservoir.

For best results:

  • If you have tried inferior products flush your cooling system with clean water after disconnecting bottom radiator hose. Do not use a flushing agent.
  • If you have flushed the system reconnect bottom radiator hose.

Additional Steel Seal Directions for Back Pressure:

These directions are for people that have a lot of back pressure building up in the cooling system, usually shown as bubbling in the header tank or air forcing past the coolant cap.

  • Locate the cylinder causing the bubbling in the overflow tank or back pressure. (Remove plugs one at a time until bubbling stops)
  • Before starting the engine, remove the spark plug or injector from the cylinder that was causing the bubbling in the overflow tank or back pressure. If accessible, remove injector wire from that cylinder. This will limit the amount of unburned fuel going into the combustion chamber.
  • If you cannot find the spark plug/cyllinder that is causing the back pressure, run the engine with the coolant level down to the top of the radiator core and with the radiator cap off or leave the expansion cap off the expansion bottle with water only just visible.

Steel Seal Frequently Asked Questions

What is the background of the Steel Seal™ product?

The Product was developed in the USA and has been through some very strict independent and laboratory testing. Scott Laboratory has performed a thorough evaluation of both Steel Seal™ and its competitors and found Steel Seal™ to be superior to all products tested. Steel Seal™ has been used successfully in hundreds of thousands of vehicles. Steel Seal has been on the market since the November of 1999. It rolled out by sending 80,000 infomercial style videos to nearly every mechanic shop in the states. This was followed with advertising in Motor Age, Motor, Underhood Service, Auto Remarketing, Used Car News, Used Car Dealer and Tech Shop. The combined circulation of these magazines literally reaches nearly every shop manager, mechanic and used car dealer in the United States. The major advantage of Steel Seal is the durability of the seal. The formula creates a seal that on a molecular level is close to the various types of metals in an engine, so that the seal will expand and contract at a similar rate with the engine. This has led to excellent repair longevity.

What is Steel Seal™ made of?

Steel Seal™ is made of several chemicals that, when combined under the right circumstances, creates a permanent seal as strong as steel.

How does Steel Seal™ work?

Once the engine is started and reaches operating temperature, Steel Seal™ is distributed through the engine. The product is drawn into the damaged area and seals the crack with a thermo-chemical bonding action process. This is similar to that of an epoxy resin, just in liquid form!

Will Steel Seal™ clog the engine’s cooling system?

Steel Seal™ is a clear formula that contains no fibrous materials or particles that could clog engine coolant passages. You can see that for yourself; just look through the bottle.

Will antifreeze compromise the seal?

No, whilst it can be used with any 'traditional' antifreeze for best results we recommend using a good quality 2 year (blue) ethylene glycol antifreeze.

How long will Steel Seal last?

With Steel Seal™ the seal is permanent under normal operating conditions, but there is always the possibility of another leak in another part of the engine.

What will Steel Seal™ not fix?

Steel Seal™ will not seal leaks in hoses, seals, water pumps, or extremely large cracks in the head or block resulting in the vehicle not starting. If it does not run Steel Seal cannot work as it relies on temperature and pressure.

Is Steel Seal a scam?

No, Steel Seal is not a scam and we offer an easy to claim money back guarantee. Please speak to one of our many stockists to see how confident they are in the product.

What do I do if I have used an inferior or other product making similar claims?

There are several good quality products on the market such as K-Seal, Holts Radweld and Seal Up, however, they all rely on fillers unlike Steel Seal and can therefore break down. The cooling system must be flushed thoroughly with water, NOT a flushing agent.

Are there any special precautions I should take when using Steel Seal™?

Steel Seal™ should be kept out of reach of children. Avoid eye or skin contact. If eyes or skin become irritated with Steel Seal™, rinse with cold water immediately. If swallowed, do not induce vomiting. Call a physician immediately.

How much do I need?

Engine Size - Bottles
Up to 2.5 - 1 bottle
2.5 up to 4 Litre - 2 bottles
Over 4.0 litre - 3 bottles

Does the treatment time vary depending on how many bottles of Steel Seal™ I use?

No, the treatment time for the procedure will be the same regardless of how much Steel Seal™ is introduced. We recommend running the vehicle for 30 minutes after it has reached operating temperature. This is the same whether you require 1, 2 or 3 bottles of Steel Seal™.

What happens if the retail customer comes back to me to uphold the guarantee? (Trade only)

Simply direct the customer to us, Steel Seal. Direct either by phone 0871 288 7125 or email We then deal with your customer directly, should your customer want you to forward their details to us, the same applies.

Should the coolant system be drained prior to use?

You need clean coolant in the system, if yours is old or full of oil you must change it first then add Steel Seal.

My vehicle is leaking oil at the head gasket?

Steel Seal will not fix oil leaks, only coolant related leaks on the head gasket.
Nothing stops head gasket oil leaks but replacing it.

I'm trying Steel Seal for a second time as my car's still overheating, do I need fresh coolant?

If the coolant was fresh and clean add Steel Seal, if dirty, flush it first.

My Steel Seal has a white sediment in the bottom of the bottle, is this still safe to use ?

Steel Seal is absolutely fine to be used in your vehicle, the sediment in the bottle is built up over time as the product sits. Simply shake the bottle before use and the sediment will disappear.

If you have any questions call 0871 288 7125 (UK)

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Why Steel Seal?

Because Steel Seal simply repairs blown head gaskets, cracked blocks and warped heads and comes with a Lifetime Money Back Guarantee for when in the unlikely event it fails to do so.


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Steel Seal Ltd, Automotive Brands Building, 30 Bidavon Industrial Estate, Bidford-Upon-Avon, Warwickshire, B50 4JN