PDA

View Full Version : RTV/Gasket/Sealant Do's & Don'ts?


pleiades
07-09-2010, 06:44 PM
I'm preparing (collecting parts, spending $$$) to do overhauls of my cooling system, double vanos, and valve cover gasket.

My Hepu water pump arrived today. Although it has a big fat O-ring, it did not come with a gasket for the bolt-on surface mating against the engine block. What should I use? Permatex Ultra-Grey or something like that?

Also, reading up on the vanos diy with valve-cover gasket replacement, I recall mention of a sealant of some kind being used with the valve-cover gasket. On other forums (other cars), I've read this is a no-no because it can compromise the chemical stability of the gasket rubber. Recommendations I've seen say to simply lubricate the new valve-cover gasket with engine oil.

If there's a sealant DIY or FAQ around here, someone point me there with a link, please?

JasonSC540ia
07-09-2010, 06:57 PM
I always use a very light layer of red RTV on the serfaces you are referring to. It is probablly not necessay, but I like the asurance/peace of mind it gives me.

pangolin
07-09-2010, 06:59 PM
go to miscellany
http://blogs.automobilemag.com/6553335/editors-soapbox/vile-gossip-hondas-product-line/index.html

For your waterpump, that surface doesn't need to be sealed, thats what the o-ring is for. A REALLY THIN layer wouldn't hurt. The only bad thing is that, it might be harder to remove.

For your valve cover, a bead along the outside perimeter of the valve cover gasket should be helpful. But let it cure fully, just in case, some oozes into the oil containing zone. It should cure fully nonetheless, before operating.

pleiades
07-09-2010, 07:24 PM
go to miscellany
http://blogs.automobilemag.com/6553335/editors-soapbox/vile-gossip-hondas-product-line/index.html

For your waterpump, that surface doesn't need to be sealed, thats what the o-ring is for. A REALLY THIN layer wouldn't hurt. The only bad thing is that, it might be harder to remove.

For your valve cover, a bead along the outside perimeter of the valve cover gasket should be helpful. But let it cure fully, just in case, some oozes into the oil containing zone. It should cure fully nonetheless, before operating.

Well, the operative word above may be "operating." I'd guess if you are overhauling your cooling system, the first thing you'd want to get installed is anything that requires sealants with curing times. I've read that the time can be anywhere from hours to overnight. So... that begs the question. Do you wait until the sealant has fully cured before adding coolant back into the car?

Just did some biceps exercises with my Bentley and noticed on 117-43 they mention using Three Bond 1209 in a few spots along the half-moon sections of the valve-cover gasket etc. Do BMW dealers sell the 1209? I'll find out shortly, can't seem to find the stuff anywhere else. All 3M or Permatex around here....

pangolin
07-09-2010, 07:35 PM
Probably not, or was it called BMW1209? Then yes. The Honda Bond mentioned in the article is used to seal oil pans, as well as other uses. I don't think the Honda dealer is any better than the BMW dealer, the BMW dealer has a better dispostion, so you feel better about the overpricing.

If you use any RTV sealant clean the surfaces, apply, then, let it cure, before adding coolant, or letting oil circulate.

shenecke
07-12-2010, 02:50 PM
Use "The Right Stuff" from Permatex. Best RTV sealer in the world. Talked to a rep from Permatex, they make the other colored stuff for personal preference, but that stuff is the best they make. GM uses it a the factory in their marine and corvett engine builds. My marine GM engine that was built by Mercruiser used that at the factory build and does'nt leak after 24 years of use!

cn90
07-12-2010, 03:09 PM
The WP O-ring seals by sideway expansion. No gasket on the mating surface.
Do NOT apply RTV on the O-ring, it may make it worse (bits and pieces of RTV may break off and clog the coolant passages).
I applied a thin smear of wheal bearing on the O-ring to ease it in. Four (4) years later, no issues.

pleiades
07-12-2010, 04:04 PM
cn90, so.... not even a thin RTV coating on the WP mating surfaces? I can see from where the O-ring goes that there should be no leaking out past the O-ring, and that if the O-ring were leaking, it might be best to know about it (visible leaking out the pump/block interface). Guess I'm still uncomfortable not putting something around the metal edge of the WP....

gtxragtop
07-12-2010, 06:35 PM
cn90, so.... not even a thin RTV coating on the WP mating surfaces? I can see from where the O-ring goes that there should be no leaking out past the O-ring, and that if the O-ring were leaking, it might be best to know about it (visible leaking out the pump/block interface). Guess I'm still uncomfortable not putting something around the metal edge of the WP....

No sealant came on the water pump from the factory and no sealant should be used. The O-ring will do its job as designed. As for a lubricant, make sure all surfaces are clean and lubricated the O-ring with coolant and lubricate the block where the O-ring will seal with coolant.

cn90
07-12-2010, 08:55 PM
Trust me, the idea of using a thin smear on gasket and O-ring has been used by indy for so many years.
I have done this in so many cars, zero issues. Actually the grease helps the O-ring slide in, smooth like butter.
Plus the WP outlet is machined in a "tapered manner": as you enter the hole, it gets a bit smaller, thus the tight fit of the O-ring.

Stop worrying, people have been installing WP O-ring, either wet it with coolant or grease, for years and years with zero issues.