Why you should never use RTV silicone on gaskets
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- Опубликовано: 8 фев 2025
- Unless you are dealing with a metal type gasket you should be careful when using RTV silicone on gasket material for the simple reason that it creates a very slippery surface and can cause the gasket to squish out and possibly tear. Just say no to excessive RTV silicone usage and help save a mechanic.
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When used correctly...the hi temp sealer works great...I've used it for years and no problems.
Same here.
What brand do you recommend?
@@fightintheshade Permatex.
Right. I always use the right stuff on every gasket. Works great. Never get leaks.
I've gone without it for years with no problems so why make a mess for next time you have to remove it and risk clogging oil flow?
From the looks of that red rtv (brittle and no adhesion) , the vehicle was put back into service before the rtv was fully cured. The high temp red and ultra copper rtvs work great, for pretty much everything as long as they are fully cured (and then some!!) before being put back into service.
There are 3 people you can’t trust in this planet. Your lawyer, your wife and your mechanic !
If you have a wife then what about your gardner, mailman and the milk man?
@@subjektivegaming thousands of car every single month? that comes to 34 cars a day if you are not taking a single day off. seems like you are a liar or just like to exagerate or have no idea what you are talking about.
Very interesting, Dirko HT Red is a high temp silicone used for all manner of gasket making (has been used by stihl in their engines for decades).
The quality of sealants, paints, glues, et cetera, has improved dramatically in the last five years. When surfaces are prepped properly, there are many situations where a good sealant alone, is the best choice. You have to pick your spots.
Gaskets have a job and they do it well on a perfect mating surface without the unwanted assistance of any silicone based sealants. Few mating surfaces are perfect though so a very light smear of non setting aviation gasket sealer is all thats needed on all cork/rubber and silicone gaskets.
Amen
Replaced the oil pan gasket on my minivan.
I did not use form a gasket. I did use a silicon paste. For automatic pans lots of shops use the black gasket maker but I always use a gasket.
Happy Motoring.
I'm glad to hear you say that. In the next couple of weeks I'm going at a leaking axle gasket despite good practice with no silicone, just a cork gasket. The mating surface isn't quite right, the cast iron is broken right beside the sealing edge. So I'm going to try to build up the broken cast iron steel to a flat surface, and have been tempted to consider a little RTV at that spot because of the unusual situation. Maybe I'm better off going with RTV alone.... It seems the slippery nature of RTV can interfere with the sealing property of gasket material.
Hello Dave. Looking forward to that video. I've had terrible luck with differential cover gaskets. Its to the point where I only use the gear oil rated Permatex and no gasket. I also let it set up for 48 hours before putting any fluid in if at all possible. Did this when I replaced the seals in the front D44 of my 98 Ram same as you did. No leaks!
Agree with El Cheapo, loose the gasket and put a nice bead of ultra gray on it and you’ll be golden. I’ll watch for your vid as well. Blessings gents.
My wife tells me to not make videos , Tim you have the best wife ever . Keep filming bud your the best automotive channel in Fairbanks Alaska 👍👍🇱🇷
Haha. Will do brother.
@@ThecardoctorTV Well, close enough. (ha ha)
@@ThecardoctorTV even tho you film from Alaska I been watching your vids to fix cars in the south no rust here. and south main auto is nothing but rust 3 different places thanks tim
Sorry for nitpick, but i live in Fairbanks - he’s in Anchorage.
@@matthewbrice737 He knows and is just trying to pump my nads. How is spring so far up there? I still have snow in my yard here.
On something very large like an intake manifold, I will not use RTV. I started buying a lot of gasket paper so I can make my own gaskets. Generally, I would prefer to wait for a gasket for max of 30 days instead of using RTV.
I used RTV on the thermostat housing because it is nearly permanent and does not require removal fo service. It worked great. Bu I don't want to use this on the throttle body even if the throttle body gas low spots or holes on it. I wait patiently for the gasket. There are many things to do on the engine bay.
This is standard practice on the Toyota 4AGE. It comes off easily with the handheld drill and a wire wheel attachment. The best way to do this is to put a 3 mm line on the inside of the screw holes on the block, then you set The oil pan on top and push it a little bit, then tighten it down after a couple minutes. They make an oil pan tool for this really easy to use.
This just gives RTV a bad name.
Whoever did that gasket used way too much RTV, probably over tightened the bolts (deforming the pan) and likely applied the RTV to a oil soaked gasket.
I always use RTV; never had problems. However, I apply a VERY small skin coat to the gasket surface and allow it dry for 15 - 20 minutes before I attach the gasket. It helps keep the gasket in place when I attach the pan. Also, I make sure the pan is torqued down in a star pattern in at least three iterations.
RTV works great as long as you follow some basic rules. If applying to a gasket, use a small skin coat. If using as a gasket, apply a continuous bead. No matter what, you always need the RTV to dry for 15 - 20 minutes so it becomes firm yet tacky.
*skim coat
Q: What’s the best way to skim it? What side of the gasket should it be applied to? The engine side or the cover side. Thanks
@@ryanflaherty3153 Ryan, "skim"-coat is when you properly apply "skim-milk" to BOTH surfaces of the part(s) to be assembled, before applying the gasket-sealer itself.
Ok, aren't you showing an EXTREME example here? That person obv put like a one inch bead - way too much - What would have been the results if he used a 2 millimeter bead instead?
As I understand it, rtv is supposed to be used INSTEAD of a gasket, not with a gasket.
Yes
For this reason.
On subaru boxers you are actually suppose to supplement the valve cover gasket with rtv in several areas before reinstall.
I think what has happened here is the original gasket maybe started leaking and they haven't had ramps to lower the sub frame so just released the bolts enough to prize the sump open to squeeze rtv in and used far to much. Dealers cutting corners to save money 😩
The person that did the job probably used the old gasket and siliconed both sides and charged the person for a new gasket. Know a few shady mechanics Tim. Keep
Them coming.
I used gasket sealant for a rubber gasket on a machined surfaced for a transmission pan. Never do it. Had a leak and thankfully catched it in the shop. Use rtv only if your pan previously came with only RTV.
oh I remember being young and foolish. That was many mistakes ago. Thanks for the trip down memory lane Tim
yup, used a cork ebay gasket on an oil pan once, didn't have a torque wrench rated for inch-lbs, had to go back later with the recommended rtv
That you for this video ! Great information on how not to use RTV with cork.
Good day from Ont. It was good that you showed this. It is certain that the person who done this did not know, if mechanic he could keep on doing it. Thanks
I’m sure they are still doing this thinking it’s a good thing. Maybe they will watch the video and learn something.
Old cork gaskets thing of the past aluminium sumps now use hi temp silicone preparation is the key for a good seal and keeping oil in its home 😁
I like your restraint. So carefully not ranting about knuckleheads. 👍
Thanks to your wife. We all need all the videos you can make. Thanks a.
She’s the best!
....RTV will hold 2 stoke crankcases.
The old carbureted jet ski engines were 2 piece & siliconed crank blocks, there was no gaskets. Silicone RTVs different with completely dry surfaces.
Looks like somebody didn't have a new pan gasket so they used the silicon on a oil soaked gasket.
🤣🤣🤣🤣🤣
IMO diy gone wrong
He would have been better off completely removing the old gasket and applying a continuous bead of RTV and letting it set up for 15 - 20 minutes before torquing it down.
@@lizardking8388 Just a guess, but, the bolts were loose, so he probably put a big bead of silicone on the oily gasket, put it on finger tight, and then forgot to tighten after 20 minutes. The previous mechanic is lucky he's not replacing a motor TBH.
atleast they should of used black 1 minute gasket maker
The EXACT same thing happened to me ...you can't use silicone with a gasket.....the silicone sticks better to the gasket than the metal and when it dries the "siliconized " gasket is so slippery it breaks in thinner places like around the pan bolts and splits open. If you attempt to snug the pan down, even to a low manufactures torque of around 8 ft pounds, the gasket squirms and breaks even more and the leak increases. Who knew??
Correct, same thing happened with me when I put RTV on my gasket to the trans pan. I only put it on one side and that was the only side leaking
The squirming on a oil pan gasket has happened to me on a brand new gasket why is that? i used no silicone and on even low torque it looked to squish around to much just like you said
Some vehicles don't use gaskets for the oil pans. Case in point, the Chevy Cruze. Factory uses silicone and not a gasket for the oil pan seal. The more you know.
Toyota 4ag is the same way. Alot of older hondas use just rtv on their oil main rear main to block and timing chain covers.
No reason to use that much RTV!!! I never use that stuff other than to tack the gasket to the part. It does come in handy when you run into a situation of some bent flanges. But you can usually straighten that stuff out with a hammer. Good video on what not to do!!
Sounds like my father in law every time something happened it was someone vandalized it 😷😂
My father in law was the other guy. Putting silicone caulk on everything! Cringe worthy.
The vandals took the handles
That's the worst stuff to use and usually ends up splitting the gasket when the pan is over-torqued trying to stop the leak caused by the RTV...not to mention the cleanup sucks. I use Permatex 82180 Ultra Black Maximum Oil Resistance RTV Silicone Gasket Maker for the seams.
Good stuff. I use the ultra gray in a lot of applications but once it dries it’s like cement. Haha.
@@ThecardoctorTV Yep I use it also
I paid someone to reseal an oil pan on my 99 corolla LE. He used the black oil resistance RTV. is this okay?????
@@ThecardoctorTV love the Grey stuff
I hear you buddy! I see this stuff all the time and I am in the auto body industry. Great call on the alignment after loosening the sub frame. Most shops won't include on their estimate of repairs or even tell the customer of the potential of needing the alignment afterwards. Now you just need to find a good alignment tech who is committed to quality. Another freebie but you won over a customer. From the great state of Montana, Rick
Thank you! I do all my own alignments so that works out well for me and my customers.
Wow, That was a mess. The bad guy in this deal. Was the guy who put all that silicone on the oil pan. Awesome video thanks for sharing. Stay well and safe.
There should be laws against it for sure.
For some reason it reminds me of six guy's I saw replacing a cracked driveway in Los Angeles, 60 feet long, they didn't use a single piece of rebar, or grate, not a single compression joint. Just one long smooth surface lol. Six months later it was, pushed up, buckled, three inch wide cracks everywhere. I had warned them, but they just blew me off. I can't imagine what the cement truck driver was thinking as they spread it around. 😒
Hope you and family are safe and healthy during these wacky times! Nice video also!
Thanks. We are doing good. You do the same.
had a chrysler come into my shop like this too, no idea why they used high temp orange.
all those cork gaskets leak after a while .. i think people try to use rtv to stop the leaks . the rubber with metal gaskets work great or felpro or right stuff or anaerobic gasket maker with no gasket ..
Well its so obvious that the previous person who was there just silicone the old gasket and reused it... maybe he didn't want to wait on getting a new gasket or just cheap out... and yes silicone RTV like "Dirko black - my favorite" can be used on oil pans but not with a gasket like that. Actually silicone RTV does a better job that any hard gasket WHEN the bolts are properly torqued to spec.
The customer fortunately made the correct decision, they brought it to you. Now the job will be done the right way. Semper Fi, USMC.
I appreciate the vote of confidence but sadly after driving a short distance the customer returned complaining of vibration on acceleration. I had replaced one of the CV driveshafts while it was here and the part was defective. I felt like an idiot and should have test drove it better (not just 50')
@@ThecardoctorTV wasn't a Dorman shaft was it?😉
All of us have made that boo-boo, where after the fact, we stop and ponder about our intelligence,LOL. Guarantee that overlook did not harm your reputation!
I used permatex the right stuff 1 minute gasket maker on 1 ton ford oil pan work good, you have to use the right stuff
I’ve never used RTV on my oil pan. Plus I only use Fel-Pro gaskets on all my cars.
so....if you did!!!!!!!!!! use rtv, that can work....it must cure before before filling with oil or running the car....IF CURED it can work
If u put it on gasket it's just lightly and mostly to hold it down. When used rtv the right way it'll last
I thought you use silicone gasket when there isn't a gasket anymore/available. But here there is still a gasket, but also applied a silicone gasket maker(and too much of it).
08 Chevy 4l60 with the exhaust crossed over right in the way so the gasket and filter has to get put on after the pan is past the pipe Otherwise I never would have went for the suggestion I told em to return it once I saw the gasket material cork and paper yes rubbery silicone type gasket clean and dry on a true surface no exceptions maybe tacky red assembly stuff that’s it!
Some people can do a lot of damage with two hands
I tried too tell ‘em don’t do silicone but they weren’t having or wanted the mess mess odds what they got put a modest layer on the gasket both sides we’ll see how long she lasts
Why didn’t u show the gasket u are putting on? Cork, paper, rubber?
What are you building with all that OSB and insulation? Don't forget to silicone caulk any gaps!
Surfaces have to be super clean!! All material removed and wiped with thinner. That is what takes the majority of the time when you use silicone. The next guy has to clean it up!! Montana Rick
Carb cleaner as good as thinner?
Customer said he 'tightened' the bolts. Customer probably did the whole thing. So, customer was right; VANDALIZED!
B YENZER, yes, this is what I believe as well - customer was a BIG bosomhead for NOT researching the task at hand, + properly reading the instructons!
Any rubberized or petroleum material gasket should not be mixed with RTV as the RTV will break the gasket down. It’s on all of felpro’s instructions.
thought you were only supposed to use one (RTV) or the other (regular gasket) not both. does the RTV also fail when it's used by itself? looks terrible.
No, its perfectly fine when you use it by itself
I've used a little bit of this stuff on slip-on motorcycle exhausts and it holds up pretty fine but this just seems really dumb, like that kind of RTV isn't made for use like that. I thought the whole point of using gasket maker was because you didn't already have a solid one lol.
It was vandalised 😅 by the shop
You made this video 2 years ago. But I prefer Permatex Ultra Black or Gray by itself. No gasket. Specially the cork gaskets. Toyota which is what I have does not even specify a gasket for the oil pan. You can get a gasket in gasket sets But not from Toyota.
I’ve seen this a lot actually lol. The number one thing I hear if it was DIY is “the guy at the parts store said I needed it” and I tell the customer yeah their is a reason most of those guys aren’t actually in the shop fixing the stuff lol. Now some of them are great but some of them ehh not so much. I seen this one guy put it on his transmission pan with the gasket and it didn’t hardly seal at all it had a bigger leak than when he started he said lol.
Those control arm bushings are MINT!😯
If I’m going to combine a gasket with sealant it’s Permatex 2
@@chuckgladfelter yikes
I've done exactly the same thing on an 07 Accord due to rusty oil pan from road salt. Not RTV on gasket, replace oil pan. I am surprised professional shops use gasket with gasket makers. You are lucky that the RTV stuck to the gasket and oil pan, not the lower block.
It was on the block as well but was able to scrape it off pretty quick. What a mess!
@@ThecardoctorTV Even as a DIY'er, I know not to use RTV with the gaskets. Otherwise, what's the point of using a gasket.
Good to see you again. We've missed you for a while.
I know race car drivers that use reviews silicone on there engines. But you have to apply it correctly.
I've always used a thin layer of our TV on the gasket on both sides never had a problem
Can you repair an oil pan gasket with permatex? I have a felpro rubber gasket that has been cut. Can I still use the gasket and seal the cut together and assemble?
Not recommended. Remove the gasket and use just RTV if possible.
An old mechanic showed me to put a thin film of Vaseline on cork gaskets to keep them in place, he told me to keep a small jar in my toolbox because you never know when a guy might get LUCKY...HAHA
I would never go camping with that guy if I were you. Haha
Cork gaskets were a terrible idea. Glad they stopped using those a long time ago
As long as there's a gasket. Sitting here staring at a Ford Escape 2.5 AWD where they don't have a gasket for it but rather "Ford" recommended gasket sealant.
Just have to make sure everythings good and clean.
Doing it mobile you have to use Brake Parts Cleaner.
I think there was a hack in there or either the owner tried to possibly repair it thinking it had a leak after it had been in? Either that or being if customer says it was vandalized maybe they're trying to get it covered by insurance on their car due to damage from vandalism is about all else I can think of.
Have a good one, back to the grind now.
I see that all the time. Especially on valve cover gaskets. It makes a big unnecessary mess.
What if you use silicone only? Loctite and permatex swears by eliminating gaskets entirely when it comes to stamped parts. or valve covers and oil pans. They even recommend it for the use of high temp aircraft engines. So I think everyone is just as confused as the other.
If they sold gaskets, they'd say the opposite. 🤣
Interesting! That gasket was just a bit over smoodged! Vandals and a tube of goo!
The RTV Bandits must have been making the rounds.
Hi Tim! Was the lower control arm bushing vandalized too? 😂
Yea it's torn pretty good
Lmao! Those Vandals
No, it was just plain worn out. Haha
ok, no doubt that wasn't done properly, but to say never use silicone RTV is non sense. There are many vehicles that use silicon (or some form of liquid applied sealant) right from the factory. I have made several oil pan gaskets this way and they hold up great, in fact they are sometimes a bit difficult to remove. Last time I pulled one, just for fun, I left the oil in, pulled all the bolts and still had no leaks.
Cleanliness is most important, like you would eat off it clean.
Most of the products I have used, instruct you to hand tighten all the bolts, let dry for an hour and then crank them done. This allows for compression of the gasket, thus making the seal. Hearing the details about the bolts being loose makes me think they never snugged up those bolts, and what you showed is about what I would expect to see if that did happen.
Never use RTV silicone ON GASKETS. Silicone ok. Gaskets OK. Both at same time. Not OK
@@ThecardoctorTV agreeed
If both surfaces had been cleaned thoroughly and evenly torqued could it have worked?
I doubt it.
I ran something over is a chunk of a curb lol. and I got seepage around my transmission pan.and I've watched a couple videos already that say if you use r t v silicone on rubber paper it's going to leak.. I was told by an experienced mechanic to use Grease.. I've heard it cars getting keyed andr tires getting slashed but I never heard of a vandalized oil pan 🤣👍 that was funny thanks for the video appreciate it..I'm going to try the grease on the new pan and maybe I'll make a video and see what happens.
Thank you. I like your videos, very informative.
with sumps we use manufactures sealant and the bolts need to be torqued to spec and that red shit i would never use it , it leaks like a siff
It would have been fine with just silicone or just a gasket but they don’t play well together. RTV Aline is probably the best for this application but I don’t like it because it’s impossible to get the pan back on without dropping more of the subframe or risk scraping half of the silicone off cramming it in there. I never used that orange stuff either.
That’s horrible, South Main auto had a car come in that the previous shop used black electrical tape to fix a vacuum line. Lol
oh wow, you mean the car I worked on drove all the way from here in Alaska to Eric O's shop in NY to fix my crappy vacuum hose repair??? hahaha
Can i use Permatex Ultra Black RTV with a black metal gasket? I'd hate to vandalize my own car. lol
That’s a great combo.
Did the "other" shop have 6 employees (thumbs down)? I've used gasket maker before on little areas like on the front and rear seals of an old small block Ford intake manifold but never on an oil pan.
I guess it is just one guy and twenty cases of RTV hehe
They went to town with that silicone!
big time! haha
So the last shop didn't take the time to scrape off the old gasket or is that a new gasket? In any case way too much sealer was used.
It looks like the silicone was from the last repair. They were very liberal with their application.
@@ThecardoctorTV I see that same problem all the time. People using three times too much silicone gasket maker, don't follow instructions. Just finished installing an oil pan on a 2004 Corolla. OEM used only some type of silicon sealer, no gasket. Went back with Ultra Black, had very little press out around the edge, no leaks. :)
At least the customer didn't own a Trailblazer/Envoy/etc. with a 4.2 I6! The axle runs THROUGH the oil pan. Whole bunch more work to change one'a them beasties!
I try not to do those nightmare jobs. There’s a great 4X shop down the road I send them junkers to. I’m too old for that kind of work. Maybe I’m just lazy too.
Unbelievable. A standard replacement gasket will work best as you stated.
Thats crazy they thought it was vandalized
so, only use the dry cork gasket, no grease ever for oil pans?
You can use just rtv on oil pans. Dont put rtv on a gasket. Oil pans that have a grooved gasket you cant. Some manufacturers use just rtv on oil pans toyota 4ag is one off the top of my head. I know the 90s hondas use just rtv on the oil pump and rear main too block.
@@kylecalobtraceharper thanks!
thanks tim take us thru a alignment on your machine like how you are honest and don't swear on your channel bye the way is high tac ok to hold the gasket on your thoughts please
I use high tac. It’s great. Super weather strip adhesive is excellent as well. Blessings.
wowzers... someone did a hack job with all of that RTV.
Use gaskets only. Or if it is siliconed only use silicone. Never us gaskets and silicone there is no point
Agreed. The Honda guys would only use silicone here by the way.
Good video tim
A good mechanic would not have replaced the pan like that.
I've used RTV on oil pans and never had this issue. Who ever did this was negligent or didn't know how to use it properly.
The issue was that the tech used RTV in conjunction with a gasket.
What is wrong with people
Was that a shade tree mechanical that came inside to a shop?
Perhaps the "tech" can read service manual data.
Amazin'
Great "update" video
Tim this doesn't beat the brake pad video!!! Both sides!!!
So I bought this 1994 Toyota Hilux Surf 2.0l turbo diesel the guy lied to me said everything worked great runs and drives fine doesn't overheat nothing leaks. So I buy it of course which was the first mistake of trusting someone. What I've found is the thing overheats, checked the thermostat thing whatever it's called that opens up to allow coolant to pass from the radiator to the engine well it wasn't even there so I'm like hmm okay. Pull the $1,400 custom made Radiator, the ting was ballooned at some point and crushed all of the fins in the middle so maybe it was passing like 40% of the air it should be. So I was like well that explains why they took the thermostat out lol. Then the rear main's leaking, front main's leaking oil pan is probably leaking not that I could tell because everything's covered in oil so much oil leaking the AC fan compressor thingy was clogged up with oil because it sits under the front main seal lol. Then I start taking the motor apart well the timing belt is floppy so floppy I didn't have to loosen anything to just slide it right off, the crank shaft hits dead center on timing mark but the fuel pump is like 5 teeth off and the valve gear thing is a tooth off. So that's no good, probably why it wasn't running very good and over heating. So basically I'm re-doing all of the seals in the motor that I can get to without actually taking serious stuff apart because I'm no mechanic. Took a bit to get the oil pan / sump pan off thing is pretty massive being a diesel and how small of the motor it is but I think they used the black RTV on it because it was a huge pain to get off to the point I was bending the pan trying to pry it off. Got it all cleaned up though and it has these little grooves from one bolt hole to the next in the oil pan and I'd like to get a real gasket but all of the other stuff I ordered took like 5 months to get to me because it got stuck in customs and the shipping issues going on right now probably didn't help. Seeing as how I can't get anything for this vehicle here in the states because it's a left hand drive Japan model do I just re-silicone it back on and put extra in the grooves? I really don't wanna have to re-do the entire thing but I also don't want to wait 5 months for a part to get here. I'm honestly not even sure if I can still get a gasket for it even if I wanted to the manual I bought shows one but being a 94 model I don't know. I'm just mad the guy lied to me said everything was great and everything is definitely not great by any means the entire motor needs rebuilt lol. I guess I learned my lesson on trusting people.
I don’t get it what you said
don’t the sealant keep the gasket more secure from oil leaking out in the future?? If you use a good quality sealant, it should not be looking like this where it don’t seal the are properly
Silicone is slippery. Just causes the gasket to squish out when tightened.
I will never use silicone in those parts, thanks.good video.
Thxs Tim nice info....
The problema seems is the person WHO din’t use the rtv properly
Indeed
4:51 that's what Ned Beatty said
No shortcuts.. no cutting corners.
Do it right or don’t do it at all..
Holy crap what a freakin mess ! If they used it to hold gasket in place to re-install use single strand copper wire holy .
If I may ask .what are the torque specs? 16' lbs chevy s10 2004 my brother has one
8.7 ft lbs. for the oil pan bolts here tightened in stages. The manual recommends using only liquid gasket sealer (not paper gasket)