Most car makers have switched to liquid gaskets now in many applications to stop leaks. Solid gaskets can leak from both sides, especially if the metals they are sealing are dissimilar like aluminum blocks and steel oil pans which expand at different rates. RTV effectively bonds the two parts together (when applied correctly) reducing those two sides to effectively zero sides for superior leak prevention.
Form a gasket fail
- Thread starter LeakySeals
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Too bad the LubeLocker isn't available, I'd still opt for a gasket though.
I use gaskets on rear end covers.If it squeezes out like that, you're laying it on too thick. 2-3 mm bead max is all you need.
I prefer to not have any leaking. RTV greatly reduces the chance of that.
Me too, and never had a problem with one leaking.
And, can fill the differential as soon as you button it up.
They use it for ease of assembly and keeping sealing parts inventory down. It works better in some applications than others but IMO never as well as a physical good quality gasket (not cork or rubber cork, etc) or a poly sealant like Hylomar or an anaerobic on flanges and would never be my first choice unless there were no alternative eg intake front and rear FIP intake seals.
RTV is not very resistant to many fluids that are common to some engine oils and fluids, ester being one of them, it tends to get soggy and leak over time.
Hylomar and anaerobics are not well suited to gap filling so it is not optimal for pans. The area where mixed metal castings cause gasket issues is the head not so much parts in the lower engine areas and transmissions, gaskets have been used for decades on transmission pans and the reusable ones have proven the best there is, better than any sealer.
Oil pans gaskets with a double sealing bead of urethane are mostly leak free for the life of the car.
To each their own, those that like it and use it all the more power to them.
Well yes of course. I didn't think I need to mention it and thought it's implied you wouldn't use RTV in place of head gaskets. One view on on the subject: https://www.permabond.com/resource-center/comparison-of-fip-liquid-gaskets-to-conventional-gaskets/
A lot of what I said is in that, I didn't mean rtv should be use on a head gasket it was just an example of dissimilar metals that put a strain on the gaskets hence the use of coated MLS gaskets.
At the engine factory, RTV/anaerobic sealant is applied by robot or pneumatic application tools to precise bead width. And in many cases, there’s a robot or job aid helping guide the parts to be sealed to perfect alignment and torque.
It’s repeatable as well on the assembly line.
It’s repeatable as well on the assembly line.
AutoMechanic
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I’m going to have to ask what is a liquid gasket? Do you mean like a gasket made with RTV? I’m sorry I’ve just never heard that term before.
The hardest part of RTV with an oil pan installed with the engine in chassis is getting the oil off of the parts the mating surfaced have to be cans of brake clean dry as The Critic posted at work the industrial engines had RTV for gaskets and everyone would get call backs because the surfaces weren't perfectly oil free..
I watched The Critic reseal an lower oil pan on a Lexus RX. I can attest to him using quite a bit of brake cleaner to clean both surfaces.
when I did the IMG on a ex-friend’s Chevy, I used lacquer thinner on a cloth to get the oil off the V-bank ends.
Exactly, and the parts are as clean and oil/contaminant free as they'll ever be. Unlike the parts are going to be when the average DIYer is servicing them.
Here are the directions for Permatex Ultra black. You have to surround the bolt holes, and be careful you don’t over torque and squeeze it out. Wait 24 hours and longer if it’s colder than 70 degree F. If you are in New Hampshire in December, you’ll need to be in a heated garage. Relative humidity is important. You have to leave it longer if conditions are dryer than 50 % relative humidity. This was relayed to me by a Permatex customer service rep. Good luck. 
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Exactly which product did you use? With Permatex Ultra Black you do not wait to tighten it down.
Actually, you need to be specific about which product you are referring to. Check the Permatex website. Many remain flexible.
Www.permatex.com
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Adding to mfewtrail’s post, here are two versions of the Right Stuff Black.
