SgtSkip

I just split my trans pan gasket when I tightened up the bolts. I used ultra copper and it's a cork gasket. what did I do wrong???

mystikkal_69

iTrader: (2)

you tightened up the gasket too much.

i usually use the rubber gaskets anyways....

SgtSkip

Kinda figered... I just got a felpro rubber gasket and will not be using RTV on it. I figure it's not needed since there's no real fluid pressure on the bottom of the transmission.

jmd

iTrader: (4)

the black GM gaskets (probaly comparable to the felpro) and no RTV are what I use.

g'luck.

TKOPerformance

Ditto. The cork gaskets are junk and always seem to leak no matter what you do.

ede

rubber is the way to go, i do like rtv or high tack to stick the gasket to the pan as i install it.

83 Crossfire TA

iTrader: (2)

RTV lubricates things making it more likely for the gaskets to slide out... FWIW, Ihave had really bad luck trying to seal things up with ultra copper... seems like every time I use the stuff I end up with a leak.

ede

ok i like rtv because it lubricates the gasket better so it stays in place while i install the pan

TKOPerformance

Yeah, I use RTV to stick the gasket to the pan too. I apply a very, very small bead and stick the gasket to it. I've never had one leak like this.

Why would you use Ultra Copper for this? I believe that it is supposed to be used for high heat applications. I use Ultra Black on nearly everything engine, trans, and rearend related that needs it.

83 Crossfire TA

iTrader: (2)

I've used assorted hardening and non hardening gasket sealers/adhesives like gasgasinch (sp?), indian head, hylomar… to stick gaskets in place for assembly (FWIW, hylomar is the coolest non hardening sealer I've ever tired, with the hardening stuff I've had about the same luck with all of it, but the Indian head shellac is reliable and cheap).

I've used assorted RTV's in the place of proper gaskets, to seal joints between pieces and between gaskets, pan rails…. The reason to use copper is that it is the only one that is supposedly resistant to most chemicals and is ready to use in an hour, the rest are supposed to dry overnight. FWIW, I've had ultra copper fail within a week the last 3 times I used it to seal up a rear axle, and I can't figure out why (I'm what you would describe as religious about prep for sealing surfaces, so I really doubt that it has any thing to do with that). OTOH, I've never had black, grey or blue fail (I swear by blue, I've used it for things that it isn't even close to rated for like turbocharger flanges and never had it leak)

Chickenman35

FYI...FelPro's Technical guide specifies that you should NEVER use RTV as a sealant with any type of gasket. It is intended as a replacement for gaskets...not as a sealant.

The problem is the flexability of the RTV, which can allow normal engine vibrations to split the gasket. Particularily susceptable are thicker gaskets like oil pan gaskets and transmission pan gaskets.

RTV should NEVER be used anywhere near an Automatic transmission. Wonderfull way to have a glob of it circulate inside and gum up the works.

Specifically, for Auto Trans pans, I use the composite black gaskets ( not rubber ) and secure on the pan side only with Permatex Aviation Gasket cement ( Brush on type ).

ede

tko ultracopper is very good stuff, not that most other isn't. only rtv i use is ultracopper. have used it instead of head gaskets, not with, instead of and it worked great.

TKOPerformance

Applying a thin skin of Ultra Black to hold the gasket, and then wait until it just skins before installing it I have never had a gasket failure. I have also never had a problem with the RTV winding up inside whatever I'm working on and gumming up the works. I've certainly heard of this before, but I think that the people who experience these problems are using it as a gasket and aplying way too much. This doesn't constitute using RTV as a gasket sealant. It's using it as a gasket tack (just holding it in place).

BTW, silicone is resistant to nearly every chemical it would encounter in an automobile. Ever try to remove it? Gasoline, kerosene, ATF, and even parts washer solvent seem to have no effect on it. There are actually products specifically intended for the removal of RTV, but I've yet to try them. I usually just scrape every bit I can get off and then use either a very fine file or a sanding block to ensure that the mating surface is smooth and all the RTV is gone. Then I clean everyhting thouroughly with Brake Clean and dry it with compressed air.

83 Crossfire TA

iTrader: (2)

Check the labels, almost none of them are rated for prolonged contact to gasoline or similar chemicals.

the RTV removers are basically just paint strippers and work similarly.

ede

yep rtv and gas is a bad combo

TKOPerformance

I was really just talking about trying to take it off parts once it had cured. I wouldn' try using is as a replacement for fuel system gaskets. It turns to slime when exposed to gasoline for too long.

JP84Z430HP

Removing RTV? The mineral spirits in our parts washer WILL take it off! It takes some time of soaking though. I usually just scrape the bulk of the rtv off with a gasket scraper anyway.

RTV has it's place, and when used properly is great. As said earlier, it is for a gasket REPLACEMENT, not to be used in conjunction with a gasket. GM has been using it for many years now for sealing intake manifold's to engine blocks. This is actually one of the main places I see the stuff fail, but it takes quite a long time. I use RTV to seal differential covers most of the time (unless whatever parts I'm putting in happen to come with a black fiber type gasket). I also use RTV on Chrysler FWD transaxle pans. That's what the factory uses, and if applied properly, (i.e. not too much!) it works great.

For GM transmissions, I use the fiber-type gasket that comes in a Carquest filter kit. They use SPX filters, which are good quality, and the gaskets have 4 holes that are a bit small for you to put bolts through the pan and gasket to hold the gasket in place during installation.

TKOPerformance

Whenever I use a black fiber type gasket I always skin both sides with Ultra Black. I've had problems with using just the gasket and it leaking. It really pisses me off when I spend a long time making sure that the mating surfaces are perfectly clean and flat, then use the right gasket and no sealer and have it start leaking. This is mainly a problem on rearends. I always use the gasket to make up for big differences, and then skin both sides with Ultra Black to make up for the surface imperfections that the fiber gaskets just don't seem to be able to fill. I have found that this technique provides a permenant leak free seal and doesn't allow RTV inside the assembly on which I'm working.

I'm not a fan of using RTV in place of gaskets, except the end seals on intake manifolds. Those factory rubber ones are junk. The only time I use it instead of a gasket is when I'm in a pinch, or the correct gasket is impossible to locate or unavailable. Even then a lot of the time I will cut a gasket out of blank gasket paper that keep around the shop.

These are just my techniques and things I've gleaned from working on cars all my life. I'm sure that others have their own techniques that work well for them too, and I'm not knocking any of them. I think ultimately we all come to do things a certain way through trial and error, advice from more experienced mechanics, and things we've read. Even if a technique isn't technically correct doesn't mean that it's wrong or won't work. If you talk to any mechanic long enough you'll eventually hear at least one way in which they do things that you think is totally bass ackwards. It's always someting that they learned through experience though, and 99.9% of the time it works just fine. Another thing to remember is that what is "right" today may be "wrong" tomorrow. The information out there on working on cars is constantly changing. A lot of stuff is theoretical for years before it gets carved in stone as being one way or another. There's a lot of science in cars (chemistry, physics, math, engineering), and science isn't a fixed thing, but a collection of theories and facts that can be interpreted a lot of different ways.

SgtSkip

I bought a felpro rubber gasket and this time I didn't torque down on the bolts. The felpro geakets holes were a touch small so it would hold the bolts in place while you install the pan. Lesson learned! I'll know when I get back in a few months if it leaked...

jmd

iTrader: (4)

Well, something about that must be out of context in a way. They include that little tube of RTV with an intake gasket set for a SBC for 2 reasons: water ports & the end rails. There's no way the water ports will seal without it unless they have the impregnated rubber & some do not.


I'm really happy w/ the one piece oil pan Fel-Pro gasket for 75-85 2pc rear seal SBC and the 86-up Gen I & Gen II one. That one doesn't need RTV.


Well, I've heard this time and time again, but if you're not globbing it on in a way-too-thick bead, you've nothing to worry about. The source for the fluid into the trans goes through a filter which is going to stop any small globs of RTV that would gum up the works.

good call.



I thought it was because it was heat resistant moreso than the other colours.

I've had the grey fail as the intake endrail gasket replacement. That was the only SBC I've ever done that leaked there. I've even done them with the rubber gaskets at the ends + RTV and those couple times they didn't leak at all.


Another thing to do on smooth surfaces is dimple them. Front and rear of the block? Dimple it. Engine block decks? Dimple it. All those leaking intake manifolds happen partially due to smooth surface against smooth surface. If you give it some friction to its surface, it's less likely to happen.

And what you said about differentials: on those & thermostat housings: RTV works but a gasket generally works better. I like the o-ringed GM thermostat housing gaskets better than cleaning RTV off later. :thumbup:

JP84Z430HP

Sorry to burst your bubble here, but they certainly WILL seal just fine without RTV. I do it all the time! Not saying that it's a bad idea to use it there, just that I don't!

I would recomend using a small amount of RTV in the corners where the main caps meet the block before putting the gasket on. Cheap insurance!

This is definately a personal preference issue here, just my preference is RIGHT! (kidding)
Basically, if it works for you, do it. I do have to believe though that surface prep is the key. The cleaner and drier the surface, the better the seal regardless of the type of gasket. If I have to use a cork gasket for whatever reason, I just make sure the surface is perfectly clean and dry. Some other types of gaskets are somewhat more forgiving in this area, but it helps to make sure everything is dry anyway!

Chickenman35

Unfortunatley those filters have a very small surface area and can easily be clogged.

The other danger with using RTV near an Auto trans is the air vent hole for the fluid circuitry in the case. On the case rail there is a very, very tiny vent hole. Plug this with RTV ( and it doesn't take much ) or any type of sealant and you tranny could be in a world of hurt

One of the reasons I never apply sealant on the case side of the gasket.


As JP84Z430HP said... Factory GM gaskets seal fine with no sealants required. Talking carbed manifolds here. Gasket Cinch or Aviation cement will work as well.

Biggest problem that people have sealing intake manifold gaskets water passages is improper prep work or the improper gasket being used. Edelbrock specifically recommends Felpro Printo-Seal gaskets for use on Aluminium Intake manifolds. Stock GM " embossed " gaskets work fine as well. Fel-Pro Permatorque Blue gaskets are recommended ONLY for IRON intake manifolds with IRON heads.

The material is too hard to compress and seal properly when used with an Aluminium Intake manifold. These will leak around the water passages...they will also suck up oil from the lifter valley. But this is due to the incorrect gasket being used for the application. For an Iron manifold on Iron heads they are fine.

JP84Z430HP

Never knew of this!

At the shop we use Carquest gaskets, which are mabe by Victor/Reinz (for engine gaskets anyway). The quality is good. We rarely see any carbed vehicles anymore, but all the TBI intake jobs I've done lately have been the graphite type gaskets. They work well for the stock applications I've used them in. I believe the TBI intakes are aluminum, and I know the heads have been iron in most applications.

This has been a fairly informative thread, just reading what others do for gaskets, and prep!

One more tidbit I heard somewhere, when prepping a gasket surface to be sealing with RTV as the gasket such as intake to block, after cleaning, take a small amount of rtv on you finger and try to put a thin layer on the surfaces in question. If the RTV sticks to the entire surface, you're good to go, if not, clean it better! I use brake cleaner before applying RTV, it dries pretty fast and clean.

TKOPerformance

Every TBI intake I've ever seen has been aluminum. They are painted black from the factory a lot of times, which can make them look like cast iron. Some very early trucks used an iron Q-jet manifold with an adapter plate for the TBI, but these are rare, and obviously aren't really a TBI manifold.

I use Brake Clean prior to gasket installation too.

NAPA sells a lot of the Victor/Reinz too. I've never had one of these fail. I tend to use FelPro for performance stuff, but I may try some Cometic stuff in the near future based on a lot of reading I've done on the subject.

jmd

iTrader: (4)

They were used on 7.4L TBI trucks. I didn't know that they ever had a dedicated Rat TBI intake. Why are they rare? You think M22's are fairly common but TBI adapter plates are rare? Man...

Pat Hall

iTrader: (31)

I used ultra copper on an oil pan gasket once. What a joke! Ultra copper sucks! Also, when it comes to cork gaskets, I wouldn't even use them on a Ford if I had an alternate choice! Gasket technology has really come a long ways in the last decade or so. I wouldn't dream of using the old four piece cork and rubber oil pan gaskets now that they have the one piece ones available. I'm surprised it took gasket manufacturers this many years to come up with them. As far as sealers go, I swear by "right stuff" that comes in the can. The can is kinda expensive compared to sealers that come in the tubes, but it's worth every penny IMO. I've used it to seal every part of an engine when assembling it, used it for tranny pans, used it in place of a gasket on rear end covers and intake end rails, even on exhaust parts, and never had a single leak problem. It has the perfect consistency even when first dispensed from the can. I've seen some rtv sealers that are so runny you can't keep it on the surface of the part long enough to set up, or you have to wait forever for it to "skin" over adequately. I used to think ultra blue was the best, but that was before I was introduced to the "right stuff". I had a water pump develop a leak at the gasket after about a year using ultra blue once too. The high tack stuff that comes in the can with a brush works great when holding the gasket in position for assembly is the main concern. As stated in earlier responses, everyone has their own tried and true methods and products they swear by, I'm just adding mine to the pile of others! P.S. I forgot the other thing right stuff sealed up for me. My coolant overflow tank developed a crack all along the bottom, and it sealed that up perfectly too until I have the chance to pick up a new one.

TKOPerformance

Did you read the rest of that other post? I never said M22s were common! Only an idiot would make a statement like that.

The TBI intake I mentioned (converted Q-jet on a 454) are going to be hard to find in a junkyard, at least they are around here. I've only ever seen one.