Topic: Piss poor crankcase vent cause leaky main seal? (Read 19693 times)

ryan89crx · « **on:** April 17, 2010, 03:36:03 PM »

I just replaced my rear main about 200miles ago because it was leaking after I threw the turbo on. Now it's leaking again. I'm 99.99% sure I didn't fuck the seal up putting it in. It didn't leak for about 190 of the 200 miles, now all of a sudden it's dripping again. I'm beginning to think that it could be caused by excess crankcase pressure. I don't know why else it would be leaking.

As it sits, all I have is the VC port just sitting open, and the black box on the back of the motor just pointed at the ground via a 3/8" hose

Is this not enough ventilation? Should I drill my VC and throw in a couple 1/2" brass nipples? What are the chances it will fix my leaky main seal issues?

ratcityrex · « **Reply #1 on:** April 17, 2010, 03:39:14 PM »

Should be plenty of evac. How many lbs are you running? How big of a turbo?

ryan89crx · « **Reply #2 on:** April 17, 2010, 03:41:33 PM »

Quote from: ratcityrex on April 17, 2010, 03:39:14 PM

Should be plenty of evac. How many lbs are you running? How big of a turbo?

It's a 9.6:1 compression sohc, Garrett t3/t4 .48/.60 60 trim, and only 11psi

I ran 21psi last year, but on an 8.8:1 compression motor with the same turbo setup and I don't recall any issues. Same bottom end FWIW

Thing that gets me is that the motor had several hundred miles n/a and not a single drip of oil

ratcityrex · « **Reply #3 on:** April 17, 2010, 04:25:34 PM »

how is the dizzy seal and shit like that above the transmission? I have seen them leak down between the motor and trans and mak it look like a rear main seal, and it not be a rear main.

ryan89crx · « **Reply #4 on:** April 17, 2010, 04:28:21 PM »

Quote from: ratcityrex on April 17, 2010, 04:25:34 PM

how is the dizzy seal and shit like that above the transmission? I have seen them leak down between the motor and trans and mak it look like a rear main seal, and it not be a rear main.

Brand new, no leaks from the dizzy.

Robb · « **Reply #5 on:** April 17, 2010, 08:14:13 PM »

Rear main seal not square in the housing = Leak. Some engines/seals are more sensitive to this than others.

ratcityrex · « **Reply #6 on:** April 17, 2010, 08:29:49 PM »

What about a leaky tranny seal?

jagojon3 · « **Reply #7 on:** April 17, 2010, 08:43:55 PM »

Did you lube the seal before installing it? I have almost exactly the same evac setup with no issues.

crttaz · « **Reply #8 on:** April 17, 2010, 09:37:48 PM »

Quote from: ratcityrex on April 17, 2010, 08:29:49 PM

What about a leaky tranny seal?

better not be!

HiProfile · « **Reply #9 on:** April 17, 2010, 11:44:37 PM »

Quote from: crttaz on April 17, 2010, 09:37:48 PM

Quote from: ratcityrex on April 17, 2010, 08:29:49 PM
What about a leaky tranny seal?

better not be!

At least we know you can help him through any tranny issues cause by the n00b that rebuilt it for him.

ifly87 · « **Reply #10 on:** April 18, 2010, 01:38:22 AM »

I've noticed that crankshaft's usually have a slight wear mark where the main seal came in contact with it, sometimes a small groove. When I put in a new rear main I usually either push the seal in farther or leave it out farther just so the seal comes in contact with a different area on the crankshaft. I'm not talking alot but just a tenth of an inch or so. I'm always afraid I'd have to do it twice.

I have a -12an fitting in place of my black box, and 2 -12 lines off my VC to a vented catch can and I still get some leakage out of my brand new VC gasket. I'm running a vitara setup with .008" PtW clearance, 20+psi. When I was just running an open VC hole and routed my black box line to atmosphere I burned oil like crazy and blew oil out of every gasket/seal, so the 2 -12 lines on my VC helped alot.

caged · « **Reply #11 on:** April 18, 2010, 02:32:56 AM »

As above it may be a lip on the crank, I usually take the spring out of the seal and undo it and cut a small section out and install it back into the seal, it adds more tension to the seal on high mile cars with worn crank shafts. When you go to replace the seal have a look and see if you can see exactly where its wet.

ryan89crx · « **Reply #12 on:** April 18, 2010, 01:30:36 PM »

Quote from: jagojon3 on April 17, 2010, 08:43:55 PM

Did you lube the seal before installing it? I have almost exactly the same evac setup with no issues.

With oil yes, not grease

Quote from: crttaz on April 17, 2010, 09:37:48 PM

Quote from: ratcityrex on April 17, 2010, 08:29:49 PM
What about a leaky tranny seal?

better not be!

lol, it's not. Like I said, I just did it 200 miles ago and the trans wasn't leaking at all.

ryan89crx · « **Reply #13 on:** April 18, 2010, 03:13:49 PM »

Anyone ever used a Fel-Pro repair sleeve for the rear main?
http://www.oreillyauto.com/site/c/detail/FEL0/16275.oap?year=1991&make=Honda&model=CRX&vi=1169344&keyword=rear+main+seal&pt=02302&ppt=C0026

Just curious if it would help if my crank has too deep of grooves.

widebody93 · « **Reply #14 on:** April 18, 2010, 03:24:26 PM »

Question Rob..
When you install the rear main seal 'as I am in the process of doing so also' how do U go abouts tapping it in? I bought 2 seals just in case I messed one up tapping it in but I cant get this first one to be perfectly centered. Top is a tad further in than the bottom but its also further in than the O.E. part I just pulled out from a gash in the bottom part of it.... Just needing a pointer $:-\$

ryan89crx · « **Reply #15 on:** April 18, 2010, 03:44:37 PM »

Use the seal you remove. Turn it around, put the face on the new seal, and tap it in evenly.

On topic - Just went and bought a new Fel-Pro. When I get off my lazy ass to replace it, I'll update to how well it works

patsmx5 · « **Reply #16 on:** April 18, 2010, 04:43:47 PM »

Quote from: ryan89crx on April 18, 2010, 03:13:49 PM

Anyone ever used a Fel-Pro repair sleeve for the rear main?
http://www.oreillyauto.com/site/c/detail/FEL0/16275.oap?year=1991&make=Honda&model=CRX&vi=1169344&keyword=rear+main+seal&pt=02302&ppt=C0026

Just curious if it would help if my crank has too deep of grooves.

I've used these on a ford 351W with success. Easy to install and worked fine. But There's a way around it too. On my 98' sentra it had a huge groove wore in the crank where the front main sealed, and it poured oil bad. When I went to install a new seal I saw how bad the crank was. I just didn't press the new seal all the way in so that it doesn't "rub" in the same groove. It's like 1/8" further out than stock, so the seal touches on a spot of the crank that's not worn. Just make sure that installing the seal further in or out doesn't cause interference with anything. Like on my sentra, that seal is not very close to the harmonic balancer, but I checked and they don't touch. But there's like 20 thousands between them...

ryan89crx · « **Reply #17 on:** April 18, 2010, 04:45:35 PM »

That's pretty much what I plan on doing. I did it before and it worked well. But for some reason this time around it didn't cooperate.

patsmx5 · « **Reply #18 on:** April 18, 2010, 06:32:41 PM »

Did you install the seal dry? I either put some oil on the outside or some RTV. Either seems to work fine, but if I'm worried about it leaking I use RTV on the ouside, like on the sentra where I didn't press it in all the way, RTV helps hold it and keep it from leaking oil around the outside of the seal.

Robb · « **Reply #19 on:** April 18, 2010, 07:16:39 PM »

Quote from: ryan89crx on April 18, 2010, 03:44:37 PM

Use the seal you remove. Turn it around, put the face on the new seal, and tap it in evenly.

This.

HiProfile · « **Reply #20 on:** April 20, 2010, 09:46:48 AM »

Quote from: widebody93 on April 18, 2010, 03:24:26 PM

Question Rob..
When you install the rear main seal 'as I am in the process of doing so also' how do U go abouts tapping it in? I bought 2 seals just in case I messed one up tapping it in but I cant get this first one to be perfectly centered. Top is a tad further in than the bottom but its also further in than the O.E. part I just pulled out from a gash in the bottom part of it.... Just needing a pointer $:-\$

Figure out how far you want it in, get some spacers (paper clips?) on the bottom lip the seal could be pounded up against, and just lightly tap it around it's perimeter. Using the old seal will prevent bending anythging. Once you get it bottomed out evenly on the spacers, remove them and install.

FYI most OEM seals I've seen from Honda have a bead of light grease on the inner contact area. I've also used some red gasket seal compound when I was into building v8's for racing. Can't recall the brand.

ryan89crx · « **Reply #21 on:** May 05, 2010, 04:09:20 PM »

Well I figured out what went wrong. When I installed the seal I didn't seat it all the way because I didn't want it riding in the grooves on the crank...well I didn't seat it far enough and the flywheel was rubbing against it, which eventually distorted it and caused it to bulge and leak. New Felpro installed and I'm throwing the trans back in now.

Joseph Davis · « **Reply #22 on:** May 06, 2010, 12:11:10 AM »

Quote from: ratcityrex on April 17, 2010, 03:39:14 PM

Should be plenty of evac.

No, it's not. Which has nothing to do with rubber hose becoming clogged over time.

My old CRX with the LS swap and .60 T3 on 9 psi had that problem twice, the first time it poured oi smoke everywhere and popped out the dipstick until I realised the valvecover vent (rubber hose hanging down the back of the trans) had become clogged. The second time, it shoved out my rear main and killed my clutch.

Put a breather box with extra vents on anything not-stock, even the NA cars.

arsenio · « **Reply #23 on:** May 06, 2010, 12:23:40 AM »

Here is a neat trick. Coat the crank and inner part or the seal in valve grinding compound when you put it in.

Shits so cash.

ctr99ek · « **Reply #24 on:** May 06, 2010, 02:32:45 AM »

ryan how did the new seal turn out fully seated?

ryan89crx · « **Reply #25 on:** May 06, 2010, 12:31:44 PM »

Quote from: ctr99ek on May 06, 2010, 02:32:45 AM

ryan how did the new seal turn out fully seated?

So far so good. I just seated it all the way, put RTV on the outside and greased the fuck out of the inside of it. I haven't gotten into boost yet, but just driving normal there are no leaks

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Author Topic: Piss poor crankcase vent cause leaky main seal? (Read 19693 times)