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-   -   Fresh rebuild now runs... And leaks oil (http://forums.pelicanparts.com/911-engine-rebuilding-forum/804570-fresh-rebuild-now-runs-leaks-oil.html)

jhg41977 04-04-2014 04:09 AM

Fresh rebuild now runs... And leaks oil
 
Top of the motor, above engine tin appears dry. I have not yet looked under the shroud. Bottom of the engine on left bank is wet. Losing about a drop a second or so at idle. The leak appears to come from above the air baffles against the cylinders. Oil drips are forming at the entire length of the baffle. In the 993 this is a single aluminum piece.

It seems likely it is a through bolt o ring leak. I cannot see any through bolts so this is only a hypothesis at this point.

If it is a through bolt oring that was not seated properly but is otherwise Ok ie not shredded from install, would a hard run up the highway potentially push the o ring into proper position? I'm wondering if it wasn't seated on the thickened part as it should be and is actually on the skinny part of the bolt.

Other ideas are helpful if you think I am on the wrong track

Thanks
Jim

304065 04-04-2014 09:47 AM

If it leaks, take it apart until you find the leak. A hard run up the highway will just make it leak more and the airflow will move the oil to parts of the motor it's NOT leaking from, making it harder to find the leak.

jhg41977 04-04-2014 01:44 PM

Confirmed with a bore scope, two, possibly three leaking through bolts. On the bright side, another weekend in the garage playing with the car!

Lapkritis 04-04-2014 02:18 PM

Sorry to hear of the tough luck and need to go back in.

When you replace the o-rings try to take a look at the alternative greases that are available to dress them. Some popular greases that have been/still are widely distributed actually weaken the ring.

jhg41977 04-04-2014 02:20 PM

I dont think it was anything we coated the o ring with, we used motor oil. I suspect one was pushed too far down on the side with the nut. I'll know tomorrow and will post my findings.

Eagledriver 04-04-2014 03:48 PM

Might want to use the green viton ones instead of the soft blue ones.

-Andy

pareto 04-06-2014 12:44 PM

Green Viton and Silicone in kit...Thank you Henry Supertec for a leak free engine on my first rebuild!!....zero leaks........sealants and advice...great forum!

RedCoupe 04-06-2014 01:48 PM

I recall that Henry stated that the blue orings were especially for the 3.6 engines as they have a different configuration on each end of the through bolts. The orings fit into a recess and a stepped or top-hat washer goes on top. I have a 3.6 with leaky through-bolts that I'm tearing into before too long, so I wonder if anyone has had success with the green orings with these engines, or if you have to use the softer blue orings.

Henry Schmidt 04-06-2014 03:35 PM

Quote:

Originally Posted by RedCoupe (Post 8001095)
I recall that Henry stated that the blue orings were especially for the 3.6 engines as they have a different configuration on each end of the through bolts. The orings fit into a recess and a stepped or top-hat washer goes on top. I have a 3.6 with leaky through-bolts that I'm tearing into before too long, so I wonder if anyone has had success with the green orings with these engines, or if you have to use the softer blue orings.

We use green Viton o-ring for all case through bolts. Because the Viton is stiffer there is a slight challenge during installation. Proper lubricant (Dow55) and a custom installation tool make the installation more consistent.

For those unfamiliar with Dow 55, a few of the military applications are listed below. Although case through bolt o-rings function in a relatively low pressure environment, many of the mil spec applications are high pressure (IE: hydraulics) proving Dow 55 capable of providing exceptional service in severe environments.
The military has been testing Dow 55 o-ring lubricant for decades and still calls for it's use.


WPN SYS ID WPN SYS SVC WEAPON SYSTEM
03 F Aim Sidewinder Missile Systems (9P/L/M/X)
04 F Aircraft, Stratofortress B-52
05 F Aircraft, Stratolifter C/KC-135
10 N Aircraft, Tomcat F-14
16 N Aircraft, Viking S-3B
19 F Aircraft, Eagle F-15
25 F Aircraft, Awacs, E-3A
26 F Aircraft, F-16
35 A Howitzer, 155MM, M-198
39 N Helicopter, sea King H-3
43 N Aircraft, Hornet F/A-18
44 N Helicopter, Lamps Mark III, SH-60B
48 N Helicopter, Utility/Search and Recovery UH-1N
52 N TA-4J Aircraft
55 N Aircraft, Harrier AV-8B
58 N Aircraft, Hercules C-130F
59 N Aircraft, Hercules KC-130
63 N Aircraft, Orion P-3
99 N Missile System, Aegis Surface (Sms) Mk 7
B2 N Littoral Combat Ship, Flight 0
BE N Missile, All-Weather Anti-Ship, Harpoon (AGM-84)
C4 N Helicopter, H1 All Versions
CP N Helicopter, Advance Attack, AH-1W
ER N Helicopter, Carrier Based Asw, SH-60F
JC N Fms - Kidd Class Ddg
JD N Arleigh Burke Class Ddg
JR N Fms - Knox Class Ff
PS A SG-1139/G, Digital Data Generator
UC A Mask, Protective, Gen/Spl Purpose (M40, M17, M9 Series)
YJ N Virginia Class Submarine, SSN-774
YL N Helicopter, Seahawk, H-60
Z9 N Aircraft, FA-18, a - D, E/F, G (Growler)
ZD N LPD-17 Class Amphibious Transport Dock

Lapkritis 04-06-2014 04:23 PM

Pay attention to the grease you're using. There are VERY POPULAR greases that retailers provide that weaken the o-ring and continue to do so at operating temperatures. Many of these retailers throw around words in defense of their sale of these products such as 'superior', 'perfect', 'supposed to weaken, it's okay' or like McDonalds: 'billions served' but refuse to acknowledge there are alternatives without the same inherent flaw.

KTL 04-07-2014 06:40 AM

Really? We're going to start the thru-bolt o-ring lubricant debate again? Wow.

Oil itself actually weakens o-rings too. What alternative engine lubricant should we use to avoid that happening?

Lapkritis 04-07-2014 06:53 AM

We might be able to avoid it... I believe op was confirming the rings were installed properly. If they were then we can go ahead with the Inert Dupont option v. Reactive Dow Corning... round 17.

http://i411.photobucket.com/albums/p...oa-Beat-up.jpg

KTL 04-07-2014 07:04 AM

I think a more appropriate picture for the massive ability you possess to hold a grudge should be:

http://forums.pelicanparts.com/uploa...1396883035.jpg

LOL :D

Lapkritis 04-07-2014 10:21 AM

All kidding aside, I don't care who sells it but believe consumers should be educated so they can choose with all information before them. Speaking of which, big GMO labeling progress in Vermont. Looks like they'll be the first state to pass it as law.

lindy 911 04-07-2014 11:30 AM

Is someone kidding?

Lapkritis 04-07-2014 12:25 PM

Troops massing on the sidelines of the thread pending OP discovery.

Pelican Parts Reporters caught up with one troop without insignia named Lindy. Here's what he had to say:

"I'm not here to fight. I'm here to help my brothers."

http://static2.businessinsider.com/i...re-country.jpg

:D

Alan Goettel 04-07-2014 04:15 PM

Huh?

KTL 04-08-2014 09:50 AM

Quote:

Originally Posted by Alan Goettel (Post 8003065)
Huh?

The debate over thru-bolt o-ring lubricant and its effect on the o-rings took place in the thread linked below and that's where the jabs between Laprkritis and I are coming from.

http://forums.pelicanparts.com/911-engine-rebuilding-forum/452985-your-opinion-wanted-green-bolt-through-viton-o-rings-rtv.html

jhg41977 04-08-2014 10:00 AM

We replaced all the orings and found 1 torn completely through and one slightly shredded. The one torn through was the one I could see clearly leaking (I used a borescope). I think it was not properly seated initially and the washer pinched it when the nut was torqued. The one that was slightly shredded was right next to it, I cannot be sure if it was damaged on install or removal.

Lapkritis 04-09-2014 10:17 AM

Quote:

Originally Posted by jhg41977 (Post 8004272)
We replaced all the orings and found 1 torn completely through and one slightly shredded. The one torn through was the one I could see clearly leaking (I used a borescope). I think it was not properly seated initially and the washer pinched it when the nut was torqued. The one that was slightly shredded was right next to it, I cannot be sure if it was damaged on install or removal.

What color/material rings did you use if you don't mind me asking? As you probably already know, a Sharpie marker cap or similar with the clip trimmed off works perfectly as an install tool for the nut end so you don't have to fight over the threads. I might also recommend inspecting your washers for any tooling marks or imperfections. I found several of my washers showed tool chatter on the ring contact surface that I cleaned up before reinstalling. These chatter ridges would tend to grasp the surface of the ring if the washer moved at all which would lead to installation tearing.

http://i458.photobucket.com/albums/q...psc476ef34.jpg


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