Oil return leak?

[daren_p]

Okay this may sound abit dumb but I'm kinda stumped here. I installed the new turbo setup & it uses the FP "blue" return line. Its your basic rubber type hose with machined flanges on either end & use a Mitsu gasket at the oil pan side. My issue is I have a leak around one of the bolt heads holding the line to the pan. They are the factory bolt, which didn't leak on my old turbo setup with the factory return & are torqued to 7 ft/lbs (stock spec is 6.5). The part I'm wondering is what is actually supposed to be the sealing surface for the bolts? The bolt holes in the pan are though/open to oil & I wouldn't imagine the gasket is whats supposed to seal the threads, so this only leaves the washers around the bolt heads. Is that whats supposed to seal them & if so what causes them to leak? The only thing I can think of if the line was abit on the short side so I did have to stretch it abit to get it to fit but the flange surface it completely sealed, without any leaks.

 

[romeen]

Are you using new 6mm copper crush washers between the bolt head and flange? 1/4" copper washers will also work.

 

[oldman]

Are you using new 6mm copper crush washers between the bolt head and flange? 1/4" copper washers will also work.

Actually stock washers are aluminum but copper will work as well. Would you two stop stalking me!!!

 

[romeen]

Actually stock washers are aluminum but copper will work as well.QUOTE]

Aluminum? I never knew that. We're not talking about your Model-T, you know.

Would you two stop stalking me!!! [/

Paranoia.............classic sign of early dementia.

 

[Defiant]

http://www.dsmtuners.com/forums/showthread.php?t=104234

 

[daren_p]

Thanks for the reply's guys, boy do I feel new Never knew those were crush washers on the return/pan bolts, that makes things much more clear now Guess I just lucked out last turbo swap as I reused the bolts/washers without any issues.

 

[CanadianTSi]

Daren, I fought a leak at that exact same spot with the exact same setup last year.
The Gasket that goes between the flange and the Pan, if sealed properly will totally seal off all the oil, so if you have oil leaking out the bolt it's the gaskets fault and has nothing to do with the bolt or a washer.

Get another gasket, clean the surface of the Pan and Flange really well and put a thin layer of sealant on either side of the gasket, it should seal Perfect.

PS I'm using the stock bolts, no washers and the method described above and it seals 100%

 

[oldman]

Daren, I fought a leak at that exact same spot with the exact same setup last year.
The Gasket that goes between the flange and the Pan, if sealed properly will totally seal off all the oil, so if you have oil leaking out the bolt it's the gaskets fault and has nothing to do with the bolt or a washer.

Get another gasket, clean the surface of the Pan and Flange really well and put a thin layer of sealant on either side of the gasket, it should seal Perfect.

PS I'm using the stock bolts, no washers and the method described above and it seals 100%

Tyler, I don't see how sealing of the bolts has to do with the gaskets itself since the the bolts threads inside the oil pan, not the flange itself unless you fill the holes completely with RTV with a little luck. I too was fighting this few years ago and a new set of OEM crush washers from the dealer fixed it.

 

[CanadianTSi]

Tyler, I don't see how sealing of the bolts has to do with the gaskets itself since the the bolts threads inside the oil pan, not the flange itself unless you fill the holes completely with RTV with a little luck. I too was fighting this few years ago and a new set of OEM crush washers from the dealer fixed it.

Sorry If I was unclear but my point was the bolts have nothing to do with sealing. So washers around the bolts won't help anything.

 

[CanadianTSi]

I used my weak paint skills to illustrate my point...

The red Line is where all the "sealing" takes place, so if its leaking out the bolt its actually leaking from the seal.

 

[oldman]

Yes but the bolt hole themselves also goes through the oil pan and they need to be sealed as well, the threaded part of the bolts are actuall inside the oil pan, maybe it's different for 2G's.

 

[daren_p]

Yes but the bolt hole themselves also goes through the oil pan and they need to be sealed as well, the threaded part of the bolts are actuall inside the oil pan, maybe it's different for 2G's.

I'm almost positive your correct Bruce, that the threaded portion in the pan for the bolts go all the way though. I can see what your saying Tyler (in that very artistic drawing ) but if the bolts do infact go all the way into the pan, the gasket can seal 100% around the actual return passage & still leak though the bolt threads. That gasket isn't designed to seal the bolt threads themselves. I'm thinking in your case the sealer you used on the gasket actually filled the threads up & sealed them, which is why your getting away without any crush washers.

I stopped by the dealer & had to pick up a couple other items so I got them to order me 6 washers & a couple spare gakets so hopefully that will solve my issue. Not sure if it matters but is it better to put the gasket in one direction over the other? The stock style gasket has an extra "seal ring" on one side of the gasket. I believe I put the ring facing the pan as I though there would be more of a chance that the pan surface was uneven vs the billet flange on the return line.

Edit: Tyler, I felt inspired by your artistic ability , so I thought I'd give it a shot myself. Here's the looking straight down on it shot with the pan, return line & 2 bolts. The oil is red & you can see the source of the leak the way we figure, if infact the bolts are threaded through the pan, into the oil.

 

[oldman]

I believe I put the ring facing the pan as I though there would be more of a chance that the pan surface was uneven vs the billet flange on the return line.

I would agree with that.

 

[romeen]

The bolts definitely go through to the inside of the pan (I've removed/replaced more oil pans than I care to talk about) and the capillary action of oil allows it to find it's way past the threads making a crush washer almost mandatory.

If you look at post #8 in the link that Defiant gave he made his own drawing which shows things pretty clearly.

I have always wondered about the white ring on the oil pan gaskets. You're speculation seems reasonable Daren.

 

[oldman]

Both Tyler and Daren definitely need to take drawing classes.

 

[daren_p]

Both Tyler and Daren definitely need to take drawing classes.

Sad part is I actually took an AutoCAD course in College (& no I actually ace'd the class )

 

[Defiant]

I'm sure it would have killed Mitsubishi to just use some goddamned acorn nuts, or some other sealed fastener inside the pan. Then again, sealing the driveshaft yoke was beyond their ken, so there we are.

 

[daren_p]

Well, no wonder the one bolt was leaking. I got some replacements (with extras) from the dealer & swapped out the leaky side last night, the crush washer was barely left. Most of the center section was flatened out/cracked/missing. I installed it & ran the car for abit last night & seemed good. I haven't checked it after driving the car today but I think I'm probably good. The washer on the other side is buckleing out abit (like the leaking one was) so I'm sure its not in the greatest condition either. I was lazy & didn't want to drain the oil so I just did a quick swap of the one washer but next oil change I'll replace both crush washers & install a new gasket as this one is now covered in oil from my lazyness

 

[Defiant]

It should be safe to do this without draining the oil.