Locktite For Exhaust System?

[MikePA]

The two nuts that connect the exhaust header to the exhaust pipe on my 1994 Geo Prizm keep working loose.

Is there such as thing as Loctite for exhaust systems?

[knucklehead]

Do they have lock washers on them? I'd pop into NAPA or whoever your knowledgeable parts dealer is, and ask them about it. Try replacing them with brass nuts, if they aren't already brass. They won't rust on, either. Our Isuzu Trooper had brass nuts in a couple places and it made removing old high heat rusty parts a snap.

[MikePA]

No lock washers and I think they are brass. To be sure, I'll have to scratch one of them. There wasn't any rust on them.

[Stoneheartfarm]

Mike,

Have you got enough extra thread that you can put a second nut on each stud? I'm afraid loctite would just burn off.

Steve

[CJDave]

[img]/forums/images/icons/smile.gif[/img] Mike, I think Stonefarm has hit it. Using a second nut is really a good fix. We are rebuilding a Jeep and when I put up the engine I made special studs for each exhaust manifold and used an oversize brass nut in back and then a std brass nut against that one. [img]/forums/images/icons/tongue.gif[/img] My Chev-Lay pickups had the very same problem and the two-nut combo solved that one too. I have a slew of oversize brass 3/8" nuts that somebody gave me way back when. I'll send ya some, but yours may be metric. [img]/forums/images/icons/crazy.gif[/img]

[MikePA]

Steve and Dave, there's plenty of room on the stud for a second nut. The only problem is that I will have to take one of the nuts off, take it to the hardware store, match it to a bolt then find the same size brass nut. [img]/forums/images/icons/crazy.gif[/img]

Also, which solution is better...a second nut or a brass lock washer.

[CJDave]

A second nut is the only way I could ever keep my stuff from falling apart. The thermal cycling, hot-cold-hot-cold keeps working on the nuts and washers and they eventually loosen. [img]/forums/images/icons/tongue.gif[/img]

[Stoneheartfarm]

I've never had much luck or faith in lock washers. I double nut everything I can. Never had one vibrate loose, (at least the ones I tightened down right. [img]/forums/images/icons/blush.gif[/img] )

Steve

[CJDave]

[img]/forums/images/icons/tongue.gif[/img] A lockwasher is an anti-rotation device which will ONLY work if it can BITE into something that will not allow rotation. Like using a lockwasher on top of a flatwasher defeats the lockwasher concept since the flat washer can turn freely.....allegedly. [img]/forums/images/icons/crazy.gif[/img]

[Bird]

Dave, in my opinion that's partially true. Lockwashers provide a certain amount of spring tension between the nut and whatever they are against on the other side, as well as biting into both. If a flat washer is used, as you say, that nullifies the biting action on one side, but the spring tension against the nut keeps its threads firmly against the bolt threads, so you still have a little more "locking" action (friction) than you would have with the flat washer alone.

Well, at least that's the way I see it; no scientific proof. [img]/forums/images/icons/laugh.gif[/img]