CarNewsCafe was given the chance to test a couple of Blue Devil products for our cars. We chose the A/C Stop Leak, which is a canister of air conditioning system leak sealer, and a Rear Main Gasket Sealer product for stopping leaks in the rear gasket of the engine block.
I plan to use the rear main sealer on our 2000 Honda Civic once it’s running again (electrical problems, feel free to volunteer to come trace them, I won’t mind). For now, though, we did use the A/C Stop Leak sealer on a friend’s car with a small refrigerant leak and it worked beautifully.
The system is easy: just connect it to the input nozzle on the A/C system lines and press the top of the can to inject the sealer. Then run the A/C for a while so it can work its way through to the leak. We then added some refrigerant to top off the system and were good to go.
That was easy!
I’ve often encountered problems where the A/C or simple gaskets are leaking and the repair is going to be a huge pain or costly endeavor when it’s such a small issue that it would seem like something simpler would be warranted. More than once I’ve added make-a-gasket or similar to stop a small leak before it got bigger, but that’s not always feasible. Enter “pour and forget” products like these.
Frankly, they rarely work as advertised. If the leak is very small, then these products are great. Once the leak gets out of hand, though, you really should go through a proper repair. Further, not all leak stopping products will be a permanent fix. Honestly, most of them won’t be. They can, however, be a stop-gap before an actual repair, buying you some time or even allowing you to wait until a service interval that would otherwise involve the components in question anyway.
For example, our A/C system leak stop. We marked the leaking point with paint so that when my friend does take off his A/C lines to get to his engine heads to overhaul the valves this winter, he can repair the leak properly at that time. He just wanted to get through the summer without major issues with the pinhole leak in his A/C. This product worked perfectly for that.
Blue Devil sells several products along these lines. You can find them at store.gobdp.com. They’re also on Amazon.
Note: the author was sent products, free of charge, for this review, but was not otherwise compensated by the promoters or makers of these products.