"Mechanic in a Can" (Bar's Leaks Head Seal, Blown Head Gasket Repair)


January 11th, 2018, 4:06 pm #1

There are a variety of products that can be added to your radiator (or closed cooling system on your boat) that will seal various leaks and issues. Jaguar cars for instance, routinely added a product like this during service calls. However, the product I am discussing here can NOT be added to antifreeze so the radiator/heat exchanger system must be flushed first.

I have often joked about "mechanic-in-a-can" type products where you basically open the can and pour "something" into y your motor, but..............drumroll please..............THERE ARE PRODUCTS THAT WORK !!! Bar's Leaks Blown Head Gasket Repair is one such product, and I am amazed how well it worked.

For many months I've been dealing with a head gasket issue on my little Ford 1700 2-cylinder diesel AWD tractor. I was getting bubbles in the radiator and it was building up pressure to the point where it was causing the overflow to lose fluid and then it would overheat. I always carried a gallon of water with me in case I overheated, and on a couple of occasions I did. Well the other day I bought some Bar's Leak, and WARNING....this is NOT the stuff you pour into your radiator with the antifreeze, this is a high-end chemical product that will not work with antifreeze, and all antifreeze must be drained out, flushed, and then with clean water you pour this product into your radiator and FOLLOW THE DIRECTIONS.

In mere moments the bubbling in my radiator stopped. I am still puzzled just how the product fixed this particular issue, but it looks like a fine copper metallic for a paint job, and it has fibers and compositions that harden. In any case, THIS is something that works, it's not cheap at $8 but a heck of a lot cheaper than the alternative.

Here is some text from the Bar's Leaks web site:

Bar’s Leaks Block Seal Head Gasket Repair is scientifically formulated
to permanently seal coolant leaks that are the cause of most
overheating problems. For most vehicles, this is the last chance before
going to a junk yard or paying an expensive repair bill. This repair
contains a blend of aramid and refractory fibers giving the strength of a
bullet-proof vest and the heat resistance of fire-proof clothing. As these
particles penetrate a crack or the blown head gasket area, they lock
together and bond forming a hard permanent ceramic type seal. Your
vehicle is a good candidate for this product if it can idle for 20 minutes
without overheating or having to add coolant. Works effectively on cast
iron or aluminum blocks & heads. Detailed English / Spanish
instructions on back booklet label take you through each step of using
the product. Overheating can be caused by a blown head gasket,
cracked head or leaking block. Bar’s Leaks Block Seal Head Gasket
Repair eliminates this problem. In addition, overheating can be caused
by a stuck thermostat, bad water pump or defective radiator cap. Make
sure these cooling system parts are in good working order before using
Bar’s Leaks Block Seal Head Gasket Repair. When one of these parts
fails, it can cause the head gasket to fail.

Head Gasket Repair is NOT COMPATIBILE
with antifreeze and must only be added to
cooling system and radiator after ALL
ANTIFREEZE has been removed. Do not add
to engine oil.

Liquid penetrates large and small leaks
to form a seal actually harder than
the original head gasket.
Fiber additives lock together with liquid
to increase strength and promote a
permanent seal.

Part Number: 1100
UPC Item: 0 46087 01100 3
UPC Case: 1 00 46087 01100 0
Bottle Size: Net. Wt. 20 oz. (567g)
Bottle Dimensions: 3.4 x 1.8 x 8.3
Bottle Cube: 51
Case Pack: 4 bottles per case
Case Size: 7.2 x 3.6 x 8.8
Case Cube: 228
Case Weight: 5.8 pounds
Pallet: TI 60 HI 5 Total 300
Pallet Height: 48 inches

1 to 1.9 gallon cooling capacity use ½ bottle.
2 gallon to 6 gallon cooling capacity use 1 bottle.
Larger systems use 1 bottle for every 5 gallons of
coolant capacity.


1. Allow engine to cool. Make sure engine is cool enough so radiator cap can be safely
removed. (This could take 30 minutes or longer). Drain and completely flush antifreeze
from cooling system and overflow tank. Using a flush “T” with garden hose works best.
If cooling system is dirty, use a good quality flush following manufacturer’s instructions.
ALL antifreeze must be removed or clogging may occur.
DISPOSAL: Observe local laws & regulations. Where permitted, dispose of in sanitary
sewer system. Never pour on the ground or in a storm sewer system.

2. Shake well, Mix Head Gasket Repair in a bucket or container with approximately 3
quarts of warm water. Pour this mixture directly into the radiator. If using in a small
cooling system, like 4 cylinders with no A/C, mix ½ bottle of the Head Gasket Repair
with the warm water.
TIP: If you do not have access to your radiator and vehicle has a pressurized reservoir,
then product can be added to reservoir. If not then remove top hose where it connects
to the top of radiator and install product in hose. Reattach and tighten clamp.

3. Fill cooling system with water and reinstall radiator cap.

4. Start engine.

5. Turn heater on hot and fan on high.

6. Run engine for 5 minutes or until thermostat opens.

7. Turn vehicle off and allow engine to cool. Allow enough time so it is safe to open cap.

8. Top off cooling system with water and reinstall radiator cap.

9. Run engine at idle until normal operating temperature is reached. Continue running
engine at idle for 15 minutes.

10. Turn vehicle off and allow engine to cool. Allow enough time so it is safe to open cap.

11. Top off (fill up) cooling system with water as needed and reinstall radiator cap.

12. Run engine at idle until normal operating temperature is reached. Continue running
engine, but at high idle. (1500 RPM’s) for 20 minutes.

TIP: For vehicles with intermittent or very minor leaks, it is recommended to follow step
13 by idling vehicle for one hour.

13. Turn vehicle off and allow engine to cool for 1 hour.

14. Remove radiator cap and drain system.

15. Leave drain open and radiator cap off for 12 to 24 hours. If temperature is below
freezing, vehicle must either be kept heated or immediately go to step 17.

16. Flush entire cooling system and refill with manufacturer’s recommended
antifreeze/water mixture.

I was in the process of re-torquing the cylinder head on this little diesel and was going to add the sealer for good measure, however, as I got into the motor I decided to use the seal first and see what happened. I was going to just pour it in but found out I had to drain everything, etc., and it took several hours to go through the whole process. On a boat, I think this would work great for any engine that has a closed system with a pressurized cap. It would take awhile to drain all the antifreeze, but it's going to be a heck of a lot easier than any alternative. On marine engines with standard cooling, I would call Bar's Leaks tech guys and ask if the pressure in the cooling system is key to making this product work.


Last edited by FEfinaticP on January 11th, 2018, 4:29 pm, edited 1 time in total.

Joined: July 15th, 2005, 8:09 pm

January 12th, 2018, 5:20 pm #2

This is a 2-cylinder diesel with 25 horsepower, AWD, 16 gears, and locking rear axle. I've need driving it with a loose radiator cap due to pressure buildup in the cooling system from head gasket leak. It's now fixed with a copper/ceramic seal, hopefully permanently.

The red you see in the photo with rocker arms is not rust, it's the original glyptal paint used during manufacture.

Here is how that little tractor is used around the farm, in addition to dragging logs each year for firewood.

If the seal is not permanent then I'll replace the head gasket in the spring or summer during good weather.
For now I'm a very happy camper.


Last edited by FEfinaticP on January 12th, 2018, 5:23 pm, edited 1 time in total.