Is this safe for diesels, specifically the Duramax 6.6L?

Yes..... According to Bars Product, this is compatible with all engines and engine oils.

Can you use this with synthetic oils

Yes, I have used it with synthetic oil with no issues.

What it does with my other gasket that has not have a leak?

If I'm understanding your question correctly.... you would like to know what effect this has on gaskets that are not leaking? The answer is nothing..... Thank you Eric

Is this safe to use with other gas additives such as seafoam, lucas?

Yes there is no problem. This gets poured into your oil crankcase not into your gasoline. Seafoam usually gets poured into your gas tank to clean injectors and cylinder walls sometimes you can put it in the crankcase just about 4 oz to clean junk this does not stop any leaks usually done 100 or 200 mi before an oil change. Lucas has many products some that are injector cleaners that go into the fuel tank some that are oil stabilizers or stop leaks or friction additives that go into your oil crankcase you can have Lucas oil additive/stop leak and bars leak in your oil crankcase they don't interfere with one another

Material	Synthetic
Brand	Bar's Leaks
Package Information	Bottle
Liquid Volume	16.9 Fluid Ounces
Recommended Uses For Product	Automotive
Specific Uses For Product	Prevent Corrosion
Item Form	Liquid
Global Trade Identification Number	10046087010409
Manufacturer	Bar's Leaks
Net Quantity	101.4 Milliliters
Number of Items	6
Model	1040-6PK
Product Dimensions	19.3 x 8.64 x 5.08 cm; 3.16 kg
Item model number	1040-6PK
Manufacturer Part Number	1040-6PK
Outer Material	other
Assembly Required	No
Voltage	12 Volts
Country of Origin	USA
Item Weight	3 kg 160 g

1040-6PK Rear Main Seal Repair Concentrate - 16.9 oz, (Pack of 6)

Details

Description

Specifications

Common Questions