19 replies to this topic

[RMCSMat]

I had a small leak at the union where the spring bolt kit is. I got the new bolts and a gasket. The hardware on the exhaust system is all badly corroded so I had to cut the old bolts. I found that there was no gasket. So I figured I was going to win this one. Well... I put the new gasket in. Flat side forward and the new bolts. Tightened the nuts about as much as I could with a short wrench. Started it up and .... leaks even worse.
The Haynes manual I have doesn't address this repair.
Is there a trick to installing this metallic gasket? Do I need to torque it?
I intend to take it apart again tomorrow and see if there's a rust build up causing the gasket not to seat. Otherwise I guess I'll just get a bigger wrench and put more arm on it.
Thanks for the help..
Curt

[Fairtax4me]

Yes you have to clean the gasket surface before installing a new gasket. It has to be clean and flat. Use a wire brush or sand paper to remove all of the old gasket and any rust buildup.
The spring bolts are supposed to be tightened until the nut seats against the flat on the bolt.

[johnceggleston]

is this the donut gasket? if so the difference between aftermarket and the subaru gasket is substantial. it could make the difference.

[RMCSMat]

Substantial? Pray tell.... I didn't get it at the Subaru dealer, I got it at NAPA, so it probably qualifies as "after market".
I'm a procedures guy. This is killin' me that there isn't anything in the book on this.
Thanks
Curt

[GeneralDisorder]

I agree - dealer only on the flex-joint donuts. Get both sides VERY clean then assemble and the bolts should be run down clear to the shoulder so the springs are fully compressed.

GD

[RMCSMat]

Thanks GD, I spent an evening under it (again). Spent a lot of time cleaning both surfaces. The flat one wasn't to hard to clean, but I'm not sure it's completely flat. There is still a good amount of metal there. It's not thin or flimsy and doesn't show signs that it contacted the ground.
I put it together again and after tightening the nuts all the way down, I could still see a lot of play as I flexed the pipe up and down. It just didn't seem like the springs had enough tension to hold the parts together. I added a couple of washers to bring the tension up. It's better but there is still a significant amount of exhaust gas leaking. Not sure what to try next. Maybe I can get it up on a lift and use a wire wheel to clean some more.
I don't see how a spring connection like that stays gas tight.
Curt

[GeneralDisorder]

I don't see how a spring connection like that stays gas tight.
Curt

Hhhmmm - my experience has been that they almost never leak - even when dissasembled and reassembled over and over and over...... So something is seriously wrong with your config.... and the fact that your car is so new and here in the NW (land of no rust) adds to the mystery - I see plenty of those that are 20+ years old and don't leak a bit. Strange things are afoot at the circle-k.

Pics?

GD

[RMCSMat]

I'll try some pics. I have to find someplace to put them, crap.
stby
Curt

[RMCSMat]

http://picasaweb.goo...CM2Oi93z74X9Pg#
Here are three pics. You can see the washers I added. and how much of the gasket shows and the gap between the flanges.
Thanks for the help http://picasaweb.goo...CM2Oi93z74X9Pg#
Curt

[Rooster2]

http://picasaweb.goo...CM2Oi93z74X9Pg#
Here are three pics. You can see the washers I added. and how much of the gasket shows and the gap between the flanges.
Thanks for the help http://picasaweb.goo...CM2Oi93z74X9Pg#
Curt

Looking at your pixs, I am thinking that you have the wrong size donut gasket installed. The two pipes should be much closer together, when the spring bolts are tightened down. No torquing is necessary. Maybe NAPA got the diameter correct, but could the donut be too thick?

My experience with Haynes manuals is that their repair info is rather shallow and generic, and lacks a lot of depth on actually doing the repairs an any car they write up. It appears your experience bears this out too.

[Manarius]

When my mechanic fixed my exhaust, in addition to replacing the gasket and the bolts, he used a racheting strap to tighten the exhaust then tightened the bolts.

[Fairtax4me]

Seems to me those springs should be near full compression when the bolts are tight. I think you might have the wrong bolt kit.
This is a pic of the OE bolts:
sold here: http://subarupartsfo...hp?partid=12099
See how much more of the bolt is threaded compared to what you have? It should be drawing up much tighter, probably another 3/16" or better.
Try getting a bolt kit from a dealer. The gasket looks like it should work but "looks" and "does" are two different things.

edited to display pics in thread

Edited by Fairtax4me, 19 October 2010 - 11:10 PM.

[RMCSMat]

Thanks for the reply Rooster2.
I just picked the part from a parts line up. No choice on size. And you're right on with the Haynes point. "shallow and generic"?? how bout non existent! They don't even deal with this union. Oh well, that's why I have the USMB!

[RMCSMat]

Fairtax4me.... Thanks for posting the pics, it's so much easier. I appreciate that.
You're right on with the thread size, wow what a difference. There's probably 2x the threads on the OE kit pictured. I just went with what I could find locally. I do have a Subaru dealer local, I'll try and get a new set from them. I'm going to try to get in to the hobby shop and put this thing on a lift Saturday and wire wheel it cleaner.
I wonder what the reason is for the shoulder on the bolt. If I got a SS bolt and washers and tightened it down until the spring was compressed, wouldn't that work as well?? I could really cinch it down then.
I'll see what the Subaru dealer has for this wk end.
Thanks for the help.

[Ross]

No, you don't want to tighten teh spring down fully. There needs to be some springeyness in it for the flex joint to work, just not as much as you have.

The shoulder is so that you can tighten the nut up so that it doesn't come loose, without fully compressing the spring.

You could put more spacers on the spring head with your bolts (so that it almost, but not completely compresses it), although that might make it difficult to get the nut started....

[GeneralDisorder]

OEM parts FTW .

GD

[ShawnW]

That flange is shot too though. It may be worth it to take it to an exhaust shop and have it welded instead at this point. They would cut out the flanges and put a sleeve connection there. It wouldn't disconnect at this point anymore but you can still take the entire exhaust down rather easily still.

Try all OEM as suggested first. New donut, new spring bolts and springs including the SS nuts. Torque with two wrenches evenly between the bolts until they wont tighten anymore.

Don't over think this repair. If it doesnt work with OEM gaskets and parts move onto my exhaust shop suggestion. Ive had many of these types of fixes in the 20-40 dollar price range at little exhaust shops over the years. Save your efforts for another aspect of the car that needs attention instead.

[RMCSMat]

Thanks everybody.. I went in to the hobby shop and put it up on a lift and did some more cleaning. There really wasn't much more to get off. The big difference was the OEM parts vs the "compatible" parts purchased at NAPA.
Absolutely not the same. Not only did the bolts have 2x the thread, the gasket itself was smaller and fit into the concave area much better.

I still ended up with 1 added washer to add a little extra tension to the spring.
But, at least no leaks this time. No headaches and tight chest. Wife likes that.

I noticed my next two projects while I was under there. I think I'm missing some protection or skid plates from up front. and also I noticed that every blasted screw and nut attaching the exhaust shroud parts on are rusting away. Obviously made of the wrong material. I'll have to bust every one of them off and replace them. Is that how Subaru guarantees return visits or did I get had by a cheap shade tree mechanic.
Disappointed.

Thanks for the help all!
Curt

[Ricearu]

rust just happens... get a can of PB blaster and some new high grade hardware and go to town.
the "right" material is way more expensive over a production run. there is a reason WWII German tanks were built with bushings instead of bearings, because the parts didn't need to outlast the vehicle. it costs too much when its all going to be scrap later anyways.

Edited by Ricearu, 26 October 2010 - 12:32 AM.

[GeneralDisorder]

That kind of rust is almost unheard of out here - especially on a 7 year old car. Where did this thing come from? That looks like east-coast rot.

I have seen those bolts on my 20+ year old Subaru's not nearly so nasty and usually come right off. Stuff here just doesn't do that....

GD