Intake boot o-rings....wow

[ResidentWarui]

So thanks to all of your kind help I managed to get 7/8 of the stuck screws out! Letting the last one sit in more chemical (Seafoam) until it feels like coming out.

Check out this pic I took of one of the intake boots. The o-ring looks completly melted or something... I don't see how it could have sealed at all. This is probably why my petcock wasn't working right even though it wasn't leaking....vacuum leak.. Probably caused all sorts of other problems too.

Sorry it's out of focus but you should see what I'm talking about:


So what chemicals should I use to clean that surface. I obviously don't want to damage it. And the engine block side too.

Thanks guys

-Simon 8)

[Doctor Shifty]

The best way to clean a gasket surface is with a small carborundum sharpening stone. Keep it flat on the surface and use lots of water to rinse as you go. Things like this can be done submerged in a tub.

If you use the stone to clean the engine side, stuff a cloth into the intake so no grit can get in.

Kim

[Macmatic]

I just cleaned up the surface of my boots and the mating surface on the head with red ScotchBrite.

These arn't really sealing surfaces so you don't have to worry too much about keeping them flat. I'm sure hitting them with 240 or 400 grit sandpaper would be fine too. You DO want to clean out the o-ring groove and the area on the head where the o-ring contacts.

I also "port matched" my boots to my head after noticing a lip that projected out past the port opening the head. When I did this I made sure the intake valves for that cyl were closed and decarbonized the intake runners while I was at it, cleaning out the waste with lots of compressed air.

Good luck,
/\/\ac

[KEITH KRAUSE]

Don't use anything too abrasive on the metal surface. The o-ring is what makes the most contact but you don't want an uneven surface to cause even a small amount of "tilting" a part that must seal air.
I would use some fine steel wool to clean out the o-ring groove and the flat surface. Inspect the manifold for any cracking. Silicone spray does wonders to help rubber last longer.
I suggest replacing the Phillips screw with Allens. Torque to 6 ft/lb to avoid overly crushing and shortening the o-rings service life. Always apply a coat of hi-temp bearing grease to extend the o-ring life. Apply a coat to the surrounding metal surface too. As you evenly tighten the screws, keep an eye on the o-ring that it stays in its groove.

[mark]

I just pulled my manifolds and they looked excatly the same. The O-ring was flattened and came out in little pieces. Make sure you get those allen head screws!

[ResidentWarui]

Thanks guys. I'm going to call arround to find a hardware store that can supply the bolts.

-Simon

[jimcor]

Ain't it good when a plan comes together!

What ever you use. Be sure to stuff a rag in the engine to prevent any dust from entering the head. I used some goo-gone or goof-off, forget which and things cleaned up nicely.

[robertbarr]

My guess is, some previous owner tried to save a few bucks and installed Nitrile O-rings from some local supply house. Nice try, but this is why Viton is used in this application. The Nitrile will just fry. (And leave quite a mess, apparently!)

[ResidentWarui]

Don't use anything too abrasive on the metal surface. The o-ring is what makes the most contact but you don't want an uneven surface to cause even a small amount of "tilting" a part that must seal air.
I would use some fine steel wool to clean out the o-ring groove and the flat surface. Inspect the manifold for any cracking. Silicone spray does wonders to help rubber last longer.
I suggest replacing the Phillips screw with Allens. Torque to 6 ft/lb to avoid overly crushing and shortening the o-rings service life. Always apply a coat of hi-temp bearing grease to extend the o-ring life. Apply a coat to the surrounding metal surface too. As you evenly tighten the screws, keep an eye on the o-ring that it stays in its groove.

Keith can I use this Mobi stuff ?

I got the last screw out and bought my allen replacements. I also have some fine steel wool to start cleaning with, and super fine to finish with. Goo-gone to help it along.

Thanks guys!

[KEITH KRAUSE]

That should work. The reason I always say "hi-temp" is because the head gets pretty hot and you want the grease to stay. But if you really need hi-temp it depends on the heat rating of the "regular" grease. I think hi-temp is good for 500 degrees? Regular grease is something like 350 degrees? I'm not sure. The head shouldn't reach those temps. Right you guys?

[ResidentWarui]

That should work. The reason I always say "hi-temp" is because the head gets pretty hot and you want the grease to stay. But if you really need hi-temp it depends on the heat rating of the "regular" grease. I think hi-temp is good for 500 degrees? Regular grease is something like 350 degrees? I'm not sure. The head shouldn't reach those temps. Right you guys?

Yea the red stuff in that tin is good for 350. I don't mind picking up the hi-temp stuff if I have to..

[earlfor]

Uhhh Yeah Keith. If your cylinder head temp is exceeding 350 deg, melting grease is going to be the least of your problems. :-) :-)

Earl

But if you really need hi-temp it depends on the heat rating of the "regular" grease. I think hi-temp is good for 500 degrees? Regular grease is something like 350 degrees? I'm not sure. The head shouldn't reach those temps. Right you guys?

[KEITH KRAUSE]

Just trying to lure you guys out and participate in the discussions.
If in fact "regular" grease doesn't run up to 350, then it should be fine.
I don't know if it would thin more and tend to provide less protection over time though. I just use hi-temp because there's no doubt.
If you do any disc brake work/wheel bearing work on your cars, you need to pick up some hi-temp anyway.

[earlfor]

For high temp applications where I absolutely want no worry about the grease, I use hi temp moly anti seize. (the copper colored stuff that looks like glue and is slick as owl snit) :-)

Earl

Just trying to lure you guys out and participate in the discussions.
If in fact "regular" grease doesn't run up to 350, then it should be fine.
I don't know if it would thin more and tend to provide less protection over time though. I just use hi-temp because there's no doubt.
If you do any disc brake work/wheel bearing work on your cars, you need to pick up some hi-temp anyway.

[ResidentWarui]

Yea I ended up using the stuff I had...I figure it's not going to make that big of a difference...just help the seal an improve o-ring life...

I used the steel wool until everything was smooth although there was still some discoloration I'm not too worried about it because I got all of the residue off and like I said it was smooth. Cleaned out the o-ring groove and made sure the outside of the boot was clean and there was no steel wool threads on the inside of the boot that would then get sucked in to the engine. Put the anti-sieze on my metric replacement hardware and a very thin layer of the grease on the mating surface and tightened evenly until it was snug...

I misplaced my 3/8" 10MM socket so I can't torque them until I get a replacement...Is it that important to have it torqued properly? I mean I always use the torque specs when I have them, but seeing as how this might be the difference between getting into town on my bike to buy another socket and do other stuff, and having to ride the bus and walk a couple miles again...I might just let the torque slide this time..Unless that would be a mistake.

And yes I own a 3/8 drive torque wrench...it's handy for stuff like this. 8)