Exhaust Leak

[pctgreg]

Well I did the heater core a couple months ago....  , I couldn't catch a break with the front axle a few weeks ago...  and it looks like I have to go to battle again   My luck sucks, and now have an exhaust leak.  Looks like the headers are coming off and stock manifolds going back on. 

[RoaminGnome]

that sucks 

[Mitch]

Where is the leak? Any luck just hitting it with a spot weld?

[pctgreg]

Where is the leak? Any luck just hitting it with a spot weld?

I can't visually pinpoint where the leak is from.  The gasket looks intact from underneath the truck.  I didn't put a cheap paper gasket in either when I installed them, I went "remflex".  I tightened the collector bolts the other night hoping it was a simple fix.  On the way in today just as I was pulling in the parking lot for work, it got 2x worse.  I was going to try to tighten the header bolts up, but the stage 8's are trash.  Being stage 8's, they shouldn't have loosened anyway.  I'm praying i'll be able unbolt the headers without issues.

I ended up running out to dodge tonight and ordered $41 of bolts since I am amazed that they don't sell a kit at the auto parts store.  Picked up felpro gaskets... even though the stockers never had them.  I'm gonna blast my old manifolds after work tomorrow, and (crosses fingers) begin tear down.  Bolts come in Saturday Morning.  Guess we'll see if all goes as planned.

[Jims1dodge]

When I was playing with the old heavy metal, I usually doubled the exhaust gaskets.  Alot of the header flanges warp when they weld the tubes on, quality control being what it is I would bet that they are not true.

[pctgreg]

When I was playing with the old heavy metal, I usually doubled the exhaust gaskets.  Alot of the header flanges warp when they weld the tubes on, quality control being what it is I would bet that they are not true.

The remflex gasket is supposed to at least help a little with that.  When it is all said and done, i'll see if I can find a straight edge.  You have me curious now

[Jims1dodge]

I had a set of Hooker Headers o a 400 small block that had 1/8" bow in them.  After I pulled the flange straight I had to get half the pipes rewelded.

[pctgreg]

Well... here's the progress so far....    Pulled the stock manifolds off my shelf and as expected... rust fell off. 



Went over to a friends and did a quick blast.  There gonna rust again...  no sense in going ridiculous on the blasting.  Just wanted to get most of the rust cleaned up.



I had some "VHT" paint in the basement ( http://www.vhtpaint.com/products/flameproof/ ) which i've sprayed my exhaust pipes with ever summer to hopefully help delay the rusting process.  Figured i'd shoot a coat on the manifolds so they look appealing for now

[jcodner]

god love the rust eh.. kicks the crap out of everything

[Batman]

As far as leaks go you'll be happier with the stock manifolds, I'm sure.  The old adage I hear from the hot rod guys is "Headers leak."  I've got a set of long tubes on the '72 GMC, I finally put copper gaskets with high temp RTV and studs on 'em a couple years ago.  Haven't had any big leak problems in a couple years, but I'm constantly checking the nuts on the headers to make sure they're tight.  Mine's just a toy truck, if it was a daily driver I'd have the headers off in a heartbeat.

[kenz]

When I was playing with the old heavy metal, I usually doubled the exhaust gaskets.  Alot of the header flanges warp when they weld the tubes on, quality control being what it is I would bet that they are not true.

Yep also been there, done that. Probably went thru 5 sets of headers on my '72 Pontiac. Every time they would leak I would take them off and they would spring out of shape and never be able to get the bolt in for the last cylinder tube. Even with double gaskets and longer head bolts didn't fix the problem. Finally found some Ram Air manifolds (both sides dumped out the back end) and was good to go. Actually improved the low end response a little.

[pctgreg]

Well... I had enough last night so I am posting the progress this morn.  I got a late start yesterday as I fell asleep after my alarm went off.  I had to drive 45 min to go pick up the bolts I ordered.  (I ordered with them because I was able too after work, they are open till 9pm week nights).  Studs didn't have a flange on them like the picture showed, so I needed to find part 15.  They looked it up for me, and said the dealer about 15-20 min from my house opposite direction had them.  Well..  I get there and they don't have them.  Part 15 looks like a washer, but was trying to do it right ...   but since I could get the stock part... I opted for some grade 8 washers and fine thread grade 8 nuts.  Also picked up some flange nuts and bolts for the down tubes.

Started disassembly...  and was immediately reminded how much of a pain it was to install these    Passenger side went fine, but the drivers side was a real pain with the dam brake booster lol.  Took a while for a few bolts with the open end wrench because the tubes are in the way so you can't get a socket on them.  But... I got them off.  Bolts were in slightly better condition than I had thought, but still not going to re-use them.  I was glad the bolts all came out with no problems, as I expected the would.



They header doesn't look that bad in the picture, but i'll get a shot later today to show the condition.

Passenger side manifold bolted back up.



Had the drivers side manifold bolted up....  went to go torque them down to 25 ft lbs like they are supposed to be...  and F*CKIN snapped one of the brand new bolts I bought from dodge.  WTF!!!!   Tried to do it right... pay out the ass for the right bolts, and they can't even hold up to their torque spec.  For shits and giggles, tossed one in a vice.  Grabbed the neck with a small pair of channel locks, and bent the bolt at the threads by hand.  The picture is blurry, but there is a clean break in between the threads.  I understand the reasoning for using a softer bolt for exhaust... but damn.  I am going to pick up some new bolts (hopefully flange), and install them this morn.  Hardware store doesn't open for another hour...



As for why the headers leaked... it looks like the gasket gave up.  They were really brittle when I removed them.  The headers themselves are probably ok.

[Mitch]

Try taking that bolt back. That is some BS right there.

[pctgreg]

Had to go to two hardware stores to find enough bolts.  I decided I wanted flange bolts, because the length of the stock bolt is 3" after the washer (3.25" total length), and I could get the flange bolt in 3" which is perfect.  A regular grade 8 in 3" would have less thread contact after adding a washer, which is why i opted for the flange bolt.  I have a picture i'll post later.  All in all it bolted together nicely with the new bolts.  Fired the truck up, no leak   success!  I'll post bolt sizes later too if I remember the size.

Sent from my DROID RAZR using Tapatalk

Edit -

GRADE 8 FLANGE MANIFOLD BOLTS - 5/16-18x3"
GRADE 8 STUD NUTS - 5/16-24 (Fine Thread)
GRADE 8 FLANGE DOWN-TUBE BOLTS - 3/8-16x2.5"

Here are the flange bolts I went with.  These imho are suitable replacements for stock.  Like I mentioned the length after washer on stock bolt is 3", which is what the length of these bolts are, and with the flange didn't use a washer.


And here are the 3 year old ceramic headers.  Living up north sucks.

[Mitch]

What kind of gaskets did you use with the headers?

That really sucks, only 3 years old. Those shorties had to have been expensive.