HarleyTechTalk

Man!  I took my 124" apart this weekend to fix leaking base gaskets.  I could not believe how the rear MLS gasket just stuck to the head!  The front one was no walk in the park either.  I beat on it with a rubber mallet and it would not budge.  I sprayed some WD-40 and used a heat gun to get it to penetrate, but still had to pry them apart.

Wow!  First time for me to have gone through that, and it was an unpleasant, unexpected, and unwelcome surprise.  I actually broke one of the small head fins because I missed slightly with the rubber mallet.  Sheesh!

Ok damn so what are you going to do different this time on the base gaskets to help with the leak . I experienced this my self so that that the reason I asked thanks

Quote from: 1workinman on March 09, 2020, 04:50:25 PM
Ok damn so what are you going to do different this time on the base gaskets to help with the leak . I experienced this my self so that that the reason I asked thanks

I will post a picture of the container, but I'm going to use some stuff that T-Man uses.  Some sort of gasket seal.  I won't use it on the head gasket though, just the base.  I also got some new studs, thinking part of the problem is stretch.  Diamond Engineering head bolts with thick washers, and Terry says he torques his to 45 lbs.  He also said he does not use oil on them.

I was able to remove the pistons/cylinders without the rings popping out, so at least I didn't slip and screw that up.

The final thing I will do is to acknowledge that I got a good 20K out of it before it started leaking, and other than that the engine has given me no problems.  Perhaps I'll take that to the bank and be happy with it.

MLS gaskets do not stick unless the motor has been very hot.

Quote from: HD Street Performance on March 10, 2020, 04:55:11 PM
MLS gaskets do not stick unless the motor has been very hot.

Not unusual for a 124" to get hot.  Now I have first-hand experience that not all MLS gaskets don't stick.

So, here's some pictures of the stuff I'm going to try on the base gasket.

another pic

what the stuff looks like

I've used that back in the Shovel days, it's been around a long time. My honest opinion is it's only ok.

A few years ago I started using Versachem aviation sealer at the recommendation of Ray. This stuff is fantastic.


http://www.itwconsumer.com/versachem-products/product.cfm?id=Gasket%20Sealant%20%233%2C%20Aviation-130

Les, do some reading about toluene before you start using it. I wouldn't because I've seen people it's effected. It's NASTY stuff and actually a type of contact cement in this application. I am not for a minute saying that Tom R is a fool but there's plenty of safer options.  IMO Permatex or most of the good aviation sealers are inert, non hardening, high quality choices.

Quote from: HD Street Performance on March 10, 2020, 04:55:11 PM
MLS gaskets do not stick unless the motor has been very hot.

That is interesting because I was wondering what made them do that as I have never had that happen they have always come apart just with a bump of the palm.

Cometic MLS and steel base gaskets for example, have a super fine rubber coating.  I imagine that has a safe heat range before it cooks to the surface.  These gaskets are laid on a clean dry surface with no residual oil (including finger prints) so they would likely stick quite well.

The last couple of builds I have done, I used the spray copper gasket adhesive.  No leaks yet.

Cleane the gasket and surfaces with acetone and seal with the right stuff I use this "Potty mouth" on everything 

Quote from: Scotty on March 10, 2020, 07:15:44 PM

Quote from: HD Street Performance on March 10, 2020, 04:55:11 PM
MLS gaskets do not stick unless the motor has been very hot.

That is interesting because I was wondering what made them do that as I have never had that happen they have always come apart just with a bump of the palm.

For me too.  I've done countless MLS gaskets, off and on.  It's funny because I was worried starting the disassemble that the longer S&S cylinders might make the rockers a bit tight.  No problem there!  But I was stunned when separating the head from the jug became a "I wonder how I'm going to do this" problem.  I mean even when it started separating it, I had to reach in there with my finger and rip the gasket from the surface of the head and cylinder.  Insane!

Quote from: kd on March 10, 2020, 07:40:04 PM
Cometic MLS and steel base gaskets for example, have a super fine rubber coating.  I imagine that has a safe heat range before it cooks to the surface.  These gaskets are laid on a clean dry surface with no residual oil (including finger prints) so they would likely stick quite well.

The base gasket did not stick at all.  That was one of the reasons it was so hard to separate the head gasket.  The damn jug just flopped around when I was trying to get them apart.  I simply had no help.  It was the head gaskets that froze solid to the point when I finally did start to get separation, it was the middle layers.  I had to rip the other stuff off the surface of the head and cylinder.

Thank you to all for the comments on the sealant I showed in the pictures.  I am back to the drawing board in terms of selecting what sealant to use.  I really appreciate the comment about my safety.  I will take a look at your recommendations.

Quote from: Ohio HD on March 10, 2020, 05:27:43 PM
I've used that back in the Shovel days, it's been around a long time. My honest opinion is it's only ok.

A few years ago I started using Versachem aviation sealer at the recommendation of Ray. This stuff is fantastic.


http://www.itwconsumer.com/versachem-products/product.cfm?id=Gasket%20Sealant%20%233%2C%20Aviation-130

One of the best out there for that job. I was likely the first to use it here, way back. Having dinked with aircraft engines, it was on the shelf, so why not test it. Did not disappoint.
Ron

Quote from: Ohio HD on March 10, 2020, 05:27:43 PM
I've used that back in the Shovel days, it's been around a long time. My honest opinion is it's only ok.

A few years ago I started using Versachem aviation sealer at the recommendation of Ray. This stuff is fantastic.


http://www.itwconsumer.com/versachem-products/product.cfm?id=Gasket%20Sealant%20%233%2C%20Aviation-130

Yea I got some of that sealer already , Ray recommended it to me

VHT copper gasket cement has always worked for me

Ok, you guys made me pick up a jar of this at O-Reilly Auto Parts.  Thanks to all.

I think you'll like it, I've not had anything leak that I used it on. That includes TC base gaskets.

grew up using the permatex version on head bolts for SBC's

Quote from: ecir50 on March 12, 2020, 05:47:32 PM
grew up using the permatex version on head bolts for SBC's

That's what I have done too.  I use it where you need the sealing quality but don't want build-up.  Base gaskets would be a good example where build-up can change things a bit.  Very light coats will squeeze the excess out when torqued down because it stays soft.  Most of the more well known companies have a comparable product.  They've been discussed here before.

Use to work as Marine mechanic On Detroits Many offshore supply boats had cats and detroits Wre would help each other Cat mechs in my area used a glue that looked and smelled like gasketcinch but this stuff was tabers you had to beat cast iron oil pans off with a sledge and gasket rails where and all day affair to clean .