What Is RTV For Cars?

Room temperature vulcanizing sealant or RTV is an elastomer that can create seals or gaskets between two components. RTV silicone forms a tough and flexible rubber once it comes out of the container.

RTV is a good adhesive that can hold its shape and repel water. RTV is also very stable, which means its characteristics won’t change over time when it’s exposed to high temperatures or other compounds such as water or oil. Unlike rubber, RTV can be more resistant to cracking or hardening.

There are many types of silicone rubber, such as HTV (high-temperature vulcanization), HCR (high-concentration rubber), and LSR (liquid silicone rubber). Compared to other silicone rubber types, RTV’s main advantage is that it can be removed easily. This means mechanics can easily remove old silicone and replace it with a fresh application during service. However, RTV silicone can be more expensive and can easily attract dirt and residue. Applying RTV can also be difficult since it needs to be applied rapidly before curing.

Where Is RTV Silicone Used In Cars?

RTV silicone is called a gasket maker because it acts as a replacement gasket between various components. These include sealing the gaps in components like the oil pan, transmission, valve covers, and water pumps.

Take note that it’s a replacement, not an add-on. RTV silicone should never be used with a gasket or o-ring that’s already in place. Additionally, you should know if your vehicle or part allows RTV silicone. Some vehicles or parts require the use of an anaerobic sealer. When that’s required, you don’t use silicone.

RTV silicone shouldn’t be used in areas where there are already gaskets and o-rings on pipes.

– Anthony Harlin, ASE Certified Master Automobile Technician

How Long Does RTV Take to Dry?

Upon application, the RTV silicone will immediately react with the air and begin to cure. As long as the temperature is between 75 to 167 degrees Fahrenheit, the silicone will harden into a seal within 20 minutes. If you’re using a tool to spread the silicone, you should finish applying the silicone in 5 to 10 minutes. That said, how fast the silicone will solidify will vary depending on the amount you apply. Small quantities will solidify faster, so small amounts of silicone used to fill gaps will solidify quickly.

In rare instances, the sealant will take up to 24 to 72 hours to dry. Once the sealant is dry, it’ll continue to strengthen for up to two weeks after application.

Does RTV Silicone Expire?

You might think that RTV silicone is one of those automotive products that you use once and then store in your toolbox for years. But you might find that after a few years, the silicone has a different smell and appearance from when you originally used it. This is because RTV silicone has a shelf life, just like many automotive products.

RTV silicone has a shelf life of two years after the manufacturing date. However, some RTV silicone tubes don’t have the manufacturing date printed on the container.

There could be telltale signs that RTV silicone has expired. Some will have a rancid vinegar smell and a black fluid mixed with the grey silicone compound. However, this color and smell can vary depending on the RTV silicone.

If you’ve purchased a tube of RTV silicone, it’s a good practice to label the tube with the date you purchased it and then replace it every six months. Expired RTV silicone won’t create a proper seal or adhesion, which can cause problems when you repair your vehicle. Simply getting a new tube of RTV sealant rather than using an old one will save you a lot of trouble and effort.

How to Get Sealant for Your Vehicle

Whether you decide to use RTV silicone or another type of sealant, you should get one as soon as possible. Driving around with a leak in your transmission system or oil pan is never a good idea.  An oil leak can cause your engine to seize up, while a transmission leak can cause your transmission to fail. Both of these scenarios come with expensive repair costs, so it’s best to seal any gaps before this happens. Luckily, getting a high-quality sealant is fast and easy at CarParts.com.

CarParts.com offers a wide selection of high-quality RTV silicone and other types of sealants. Thanks to our easy-to-navigate website, you can place an order with just a few clicks. If you’re in a hurry to get back on the road, you’ll be pleased to know we also guarantee fast shipping. Order by 12 PM ET, and you can expect your new sealant to arrive in as fast as two business days.

Don’t wait until you notice a leak in your oil pan, transmission, or water pump system before sealing the gaps with RTV silicone. Check out our catalog of high-quality sealants at CarParts.com and order one for your vehicle today!