Earl Brown! Rear Main Seal Install

[Steve Wood]

As author of this thread, I thought it was clear that this was about a turbo Buick rear main seal and not a generic post.

It may seem like voodoo to you, but, it is basically the technique proscribed by The GM engineers of the Buick Division 30 years ago using the same type of sealer as discussed in the thread.  See the attached shot taken from the manual.  Note the picture showing the desired application of an anaerobic sealer as discussed by Earl and others.  Look up the suggested sealer.  It's still for sale from GM.

[Steve Wood]

After reading and watching videos, it pretty much comes down to two variations of the factory technique.  One using an anaerobic sealer on the mating faces in a very thin coat which is easy because the stuff is watery followed by torquing to spec and then the side pockets are pumped full of either Utra black/gray or Right Stuff black/gray.  De-aerating the goo with a wet probe is crucial.


The Right Stuff is a bit thicker than the Ultra but either work well.


The other version is similar but rather than using an anaerobic, it uses a thin smear of the above silicones on the face, followed by smearing the cap cavities with silicone and installing the cap (others install the cap loosely, pump full of silicone until it seeps out), then torque down, de-aerate, fill again if necessary.  Six of one, half dozen of the other, it seems.


Everyone tries to insure the seams are showing silicone and some even try to force some silicone into the seams as additional insurance.


Virtually everyone also use a neoprene seal instead of rope.


The key to success is cleanliness so the silicone sticks to the surrounding surfaces and prevents oil from leaking around the cap or through the mating surfaces.


Almost no one uses the rubber plugs that come with the seal as they do not insure as good of seal as forcing silicone into any potential leaking area.


The manual says the factory used nylon plugs but many swear their factory engine had silicone in the pockets. 

[nocooler]

Come on Steve all you need is a tube of clear silicone, it seals everything!

[Steve Wood]

Your memory is not failing at all!

You remember when he argued that a Fram Hp2 and, I think, an HP3 both would fit a Buick?  When we pointed out the threads were different, he go mad and said he had been using the wrong one for years and it worked perfectly..... ah, those were the days

[wmsonta]

Do people put sealants between the main cap and its register? I have done a number of rope main rear seals, but have not done that.
Hell, I am reasonably sure, I never used silicone sealers. Not sure it existed.

This is my part in this. How it started. Turns out not only do they, but a large number of people do.
I might as well cause more and say I have always used the neoprene side seals when available. As long as they install from the top. Put another way, installed after the main cap and before it is torqued.

[Steve Wood]

I should have linked to the Mother of Buick sites from around the beginning of the 21st century as it was where I started


http://www.gnttype.org/techarea/engine/rearmain.html

[earlbrown]

Why in the hell would you seal the sides before torquing the cap down?   What is the performance benefit in that?   


  I like The Right Stuff on the side seling areas because it comes in a Cheeze Whiz can.  (that and I have a tube since that's what seals the pan).


That was surprising to see the factory mentions sealing the parting face of the main cap.  Like that small weeping from a dry cap could be noticed next to the leaky factory rope seal.

[Steve Wood]

My guess is that it gives the sealant a larger "leak" to aim for and insures that a better seal might be obtained.  I'm not sure that is really a problem as long as the surfaces were properly cleaned so that the silicone sticks properly where it contacts the cap and it's surroundings.


Either way should work as long as one moves quickly before things start to cure.    Seems to me that your technique has less potential risk with regard to the cap not ending up fitting properly.  One can smear some silicone on the sides/grooves and install the cap and torque it down before injecting more into the pockets, but, again, I am not sure that buys anything.  I think I would rather fill each side in one pass and get the air pockets out thus creating a potentially more homogeneous fill/seal.


Probably makes no difference in the end, tho.  Using Silicone insures a solid seal if done right whereas the rubber plugs just try to fill the space and hope that pressure makes the seal.


Be damn hard to install a rope seal properly into an engine that is installed in the car without dropping the crank which is borderline insanity, IMO of course. 

[wmsonta]

"Why in the hell would you seal the sides before torquing the cap down?"

"The FelPro rubber seals come with a couple of inserts to force into the pockets after filling them."

I do not know what to say. It is as if, nobody on this forum has ever installed neoprene side seals.

Silicone in lieu of side seals did not start w/turbo Buicks. It was used on nearly every rope seal motor made as soon as it was commonly available. I would guess, turbo buicks were the last to that party based on the yrs of production. Before silicone, every kind of sealer, various compounds, cement w/ ground rubber, et al.

I will have to give all this some thought. Busy now.

[Steve Wood]

I was almost 78 years old when I posted this simple question regarding current best practices for installing neoprene rear main seals in a turbo buick 3.8.


No where that I can recall did I mention rope seals or anything such.


I hope that this is simply a nightmare rather than the alternative that I have since died and landed in hell with a devil that is intent upon breaking me to the wheel with rope seals and rubber side seals.  If I wake up to a 312 Y block ford with a rear main cap that is grooved too deep for the seal and is intent on puking oil around the seams no matter how hard I pound those side seals into the grooves, then I will know this indeed hell!    I'm sure it is because I gave my Vega station wagon body to a friend last year.


It is not that we have not used rubber side seals in the past; it is that we have found a way in the past 25 years or so to create a better seal than is often obtained with the side seals when it comes to stopping the notoriously oil drips from our Buicks. 


Progress often entails improving upon time honored practices as technology continues its relentless march.


I recall in the fifties that some added Comet to the oil when starting up a fresh small block with chrome rings to improve the seal to the cylinder walls.  Others added banana peels to howling differentials for a better trade in value and every newspaper had an ad for for a toilet paper oil filter and/or aircraft type spark plugs.  We learned and moved forward.  At least most of us did.


Damn, I am dead and this is Hell! Here comes the devil with a rat rod.

[Steve Wood]

Oh, my!!!  Here comes Earl Brown!  Damn, Earl, I thought you would be here for something more common like fornication and not for daring to advance technology!  Buck up!  I hear winter is going to be a doozy this year.  That is your pile of side seals by the Hudson Hornet.  Sorry it has only one carb!
 

[earlbrown]

The window seal in front of my main porn computer had an avalance a few weeks ago.

For some reason I stacked up all the rope seals I pulled out of NOS covers I ported way back when.    It's amazing the clutter they can make when hitting the floor and rolling under everything in my home arcade...

[wmsonta]

good luck, guys. I agree, you should use silicone in those side seals.

[Steve Wood]

When it comes to stopping oil leaks in a Buick, luck is always good to have on one's side


Good gamblers work on improving the odds so that luck has less to do with it.  That's all we are doing-using modern silicone technology for a better seal.  It's been proven for the past 20 years so maybe there will be another small leap forward coming up

[Tim Hensley]

Drip lip was it was the small  leap forward