Should You Use RTV On Water Pump Gasket? If you are dealing with a leaking water pump gasket, or you are interested in replacing one, there’s a good chance you have heard about the benefits of RTV. Many mechanics use RTV as a supplemental sealer on gasket repair jobs.
However, if misused, it can prevent your water pump gasket from forming a reliable seal, resulting in leaks. We all know how dangerous that is.
It’s okay to use RTV on water pump gaskets. But it would be best if you used it when necessary and in the appropriate manner.
Below is a guide that will give you insight on how and when you should use RTV in repairing water pump gaskets.
Should You Use RTV On Water Pump Gasket?
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What is RTV?
RTV is a popular term, but very few people know what it is and what it does. First, RTV stands for room temperature vulcanizing. This is a silicone that cures as soon as it’s exposed to air.
It does an excellent job as a sealer since it features water-repellent properties. This is also a reason why RTV is used on water pump gaskets. RTV is a strong adhesive that can resist wear while retaining its shape.
One of the critical features of RTV is its ability to vulcanize at room temperature. That makes it ideal for various repair jobs such as repairing gaskets where there is no room for increasing temperatures.
You may be wondering if it hardens at room temperature, how is it able to retain its form in the package. Manufacturers of RTV store the silicone in an airtight tube. It is only exposed to air when you squeeze it out.
What about the Water Pump Gasket?
Before digging deeper into whether you can use RTV on a water pump gasket, we must also define the latter component and why you may need to use RTV on it. A water pump gasket plays a critical role in the engine system.
This is a small sheet found on your engine made up of gasket paper, metal, silicone, and plastic polymer. The water pump gasket fills the gap between the water pump and the engine.
The water pump is vital because the water flowing from the engine block to the water pump would leak without it. This would then lead to overheating of the engine since the cooling system will be ineffective.
Diagnosing a malfunctioning water pump gasket is simple. First, you should realize a pool of water under your car whenever you park on a spot.
Secondly, the check engine light can appear. If the water pump gasket is leaking, it needs to be repaired, and that’s where RTV comes in.
When Can I Use RTV on Water Pump Gasket?
Certain scenarios make it ideal to use RTV on the water pump gasket. The first thing you have to know is that when replacing a water pump gasket, you ought to install it when it’s clean and dry.
Not unless the manufacturer recommends otherwise. Obviously, different gasket manufacturing brands will have varying requirements.
If you must use RTV as a supplemental sealer, do not use it all over the water pump. Contrary to what you may think, using RTV around the water pump can affect installation and create leaks.
The best solution is to apply the RTV on the corners of the gaskets or wherever you can see gaps.
Other than the water pump gasket, RTV can also be used on valve cover gaskets, oil pan gaskets, timing cover gaskets, and intake end seals.
Why Shouldn’t I Smear RTV All Over the Water Pump Gasket?
If you apply RTV on the wrong areas of your water pump gasket, that can lead to permanent damage. Using this silicon sealer in the wrong areas causes over-compression of the gasket. All rubber gaskets are designed to endure a certain level of compression.
If they are exposed to more compression than they can handle, the gasket will get damaged or, even worse, it can slide out of its original position, and that’s risky for your car engine.
To avoid such complications, always confirm from the repair manual whether you should use RTV on the water pump gasket in the first place.
If a replacement water pump gasket fits perfectly, there is no need for additional sealants. But, if there are gaps or the corners of the gasket seem weak, it’s crucial to seal these areas with some RTV.
One thing you have to understand about RTV is that a small amount of this silicone glue goes a long way. So, using too much isn’t the solution.
Is It Safe to Use RTV on Water Pump Gaskets?
Most gaskets these days are made of paper. When you further research the installation of such gaskets, manufacturers advise you to install clean and dry. This can leave you wondering, is it safe to use RTV.
If you seek the opinion of old-school mechanics, they will recommend using some RTV on the edges. As a car owner who wants to fix a faulty water pump gasket, this information can be confusing. And it’s okay to question the safety of this DIY hack.
We always tell our readers that they should follow their manufacturer’s instructions. It’s that simple. You will never see anything going wrong by adhering to what your manufacturer has told you in the repair manual.
If a reputable manufacturer asks you to install a water pump gasket on a clean and dry surface, adding RTV may affect compression or permanently damage the gasket, leading to leaks.
It’s safe to use RTV only if recommended in the service manual. Remember, if you leave gaps on the water pump gasket during installation, you will have to deal with leaks afterward.
In this scenario, the best thing to do is follow your manufacturer’s instructions and gut. This is because there are plenty of cheap paper gaskets out there that will require the support of some extra sealants.
What about RTV Silicone Gasket Maker?
These days, some mechanics and car owners are using RTV silicone gasket makers instead of actual gaskets.
Even though these gasket makers are cheap and offer a quick fix, they are far from being considered an alternative to actual water pump gaskets.
Water pump gaskets may seem like thin sheets made out of nothing, but they have been formulated for this particular application. RTV silicone gasket makers can’t be used as a replacement for gaskets.
Yes, it can serve you for a while, but there is a huge chance that there will be gaps, the compression levels will be off the roof, and in no time, your car engine will be overheating.
To be on the safe side, stick to OE-style water pump gaskets.
Is RTV Mandatory When Replacing a Water Pump Gasket?
First, you should know that there are different types of gaskets. If you want to replace the water pump gasket, get exactly that. Getting the right fit is essential because it will ensure you don’t need the help of a sealer such as RTV.
When replacing a water pump gasket, an RTV isn’t mandatory as long as you get the correct fit for your water pump. Another factor that ensures it fits snugly is the preparation of the surface.
The area where you install the new water pump gasket needs to be cleaned appropriately. If it’s sticky and dirty, use a strong cleaning agent and scrub thoroughly till what’s left is bare metal.
Let that surface dry, and then install a quality water pump gasket. Ensure it’s well fitted and stays in place. Connect the water pump and the engine, then monitor the performance of the gasket.
When you follow the above guide, there won’t be a need for RTV. Only use RTV to see gaps, or the gasket you are installing seems to be loose on the corners and edges.
Should I Hire a Mechanic to Repair/Replace My Water Pump Gasket?
Replacing a water pump gasket or repairing it using RTV isn’t difficult. Taking it to a mechanic is also not a solution in some situations.
That’s because some mechanics will use RTV when installing new gaskets, even when it’s not necessary. Also, when you factor in the additional costs involved, it’s better to do it yourself.
It’s so simple. You have to make a judgment on whether RTV is needed or not. If it’s not required in your water pump gasket installation, then the process is easier.
If it’s needed, no problem. Don’t smear RTV all over the water pump gasket. Just apply it on the corners or where there are gaps, and you will be good to go.
Is RTV Better than Permatex?
Permatex is a silicone gasket sealer. The manufacturers claim that it can be used instead of water pump gaskets. However, there aren’t many differences between Permatex and Water Pump Gasket.
It’s the same thing and shouldn’t be used to replace an actual gasket. You can use either Permatex or RTV as a temporary repair to your gasket issues but not a long-term solution.