Header Leak??

Discussion in 'Fox 5.0 Mustang Tech' started by smkshw, Mar 21, 2014.

  1. ive had a header leak on my drivers side ever since i put my engine in last summer,i tried a few different gaskets already,even tried copper.....anyone hear ever use some kind of gasket sealer for headers before?,is it ok to use?.....i have afr 185 heads and i want to finally fix it before i strip them taking it on and off so many times....and the tick tick tick drives me crazy!
  2. But, its Friday night and were drinkin. See ya Monday
    smkshw likes this.
  3. i hear you...my days tomorrow,i can only do one a weekend now a days....
  4. Id say your header flanges are warped
  5. thats what i was thinking?...there bbk long tubes....would you use gasket sealer?....dont know what to do?....double up maybe?...
  6. Copper rtv ftw
  7. getting scared cause every time i put it back on it feels like its cross threading,had to clean a couple up with a tap and die already....its a ***** to do each time.... think im going to get some studs this time around
  8. rtv hey?....guess ill try that....just wanted to make sure i can use it on headers,never had to before....
  9. Ditch the copper header gaskets. They're for the most part....crap. Use a good set of fiber gaskets like the stock BBK gaskets and some copper RTV. Works great. Smear a little on the header gasket where it contacts each of the ports on the head, stick it to the head and let it set up (that way, you don't have to worry about trying to align the gasket and and install the header at the same time. Next, smear some more around each individual port on the header and let it set up a little while. You want it semi dry, but still pliable.

    Bolt the header on tightening from the inside, outward in stages.

    For example ports 2-3, then 1-4 on the passenger side, then the same for the drivers side. Torque them down till they're good and snug, but not to the point where they're crushing the ever living crap out of the gasket.

    Take the car for a ride and let it get up to operating temp. Bring it home and let it sit overnight. Come out the next morning and re-tighten the headers (the headers must be stone cold in order to re-torque them).

    You might have to do this 3-4 times. A good set of locking header bolts like Stage 8 will save you a big headache later on down the road.
    smkshw likes this.
  10. good stuff....ill do it exactly like that....never thought of putting the gasket on and letting it set first thanks...
  11. Actually, the best way to do this project would be to remove the header from the car. Take the header to your local machine shop and have the flange "trued" or someone might say "milled" whatever the terminology may be, you are going to need a flat surface to fix this leak correctly. Everything above is great information assuming you have a level surface, since you header is warped you do not.

    Good luck.
  12. that would be ideal...there long tubes,bit more work to remove....if this dosnt work ill have to try that next....its not that bad though....should work..
  13. The problem in correcting it via this method, lies in the thickness of the flange. Having it plained for trueness might cure the issue initially, but you've now got replaced a flage that was previously very susceptible to warpage, with one that's even more susceptible. Since the metal is thin and there are no dowels to keep it in place, the header flange tends to move around with each heating and cooling cycle, which adds to the problem.

    Your best defence against dealing with warpage is even torque across the entire flange.

    The BBK's have a fairly thick flange, so my guess is that they're still probably pretty straight. The combination of a good gasket, high temp copper silicone and even torque should sort it out. I'd save any modifications to the flange as a last resort.
    Grabbin' Asphalt likes this.
  14. couple , of things. First Brian offers solid advice. I'll add a few things just for the hell of it.
    What length header bolts are you using. On aluminum heads you sometimes need to use 3/4" and not 1" length to get them to seat properly. It is very important especially on aluminu heads not to overtorque the bolts and to follow the proper sequence.

    Also, You can soak the paper gaskets in water overnight- I know this sounds crazy- but it does help in sealing as they expand out.

    Lastly, Take a straight edge and lay it across the header flange to see if they are warped. If they are, your options are either to remove them and attempt to straighten or I disagree here with Brian- buy a set of Percy's copper gaskets. They are soft and will seal up around imperfect flanges. Thee's a reason Ford and other manufacturers use copper gaskets from the factory and they are for the most part leak free. Hell you can reuse them as long as they are not too badly beat up.
  15. first thing i have to do is remember what gasket i used....i remember the ports for the afr heads were bigger and i got the wrong one a couple times,i ended up finding the right one online...might have been from here actually...?...but i have to do a search cant remember of hand..

    i was going to soak it over night the first time also but i i was in the home stretch and i couldnt wait ,ill try it this time though,and i did the torque sequence also....ill try the easiest first,hope the header isnt warped...
  16. i was going to work on it but i ended up cleaning it and going for a cruise instead...lol.....havnt driven it since last summer..so it didnt seem to bother me as much....lol
    #16 smkshw, Mar 24, 2014
    Last edited: Mar 24, 2014
  17. also....hope it not coming from a weld or somthing,read a few people had that problem
  18. Proably not. The BBK's are a pretty solid header for the money. Are yours ceramic coated, or no?
  19. bingo!!!! soaking fiber gaskets works quite nicely. just remember though you cannot use any sealer as it wont stick, and you want to install the gasket while it is still wet, and once installed drive teh car around the block to let the exhaust heat dry out the gasket.

    as for the copper gaskets, you need good quality ones, the cheap ones suck big time. and i second using percys copper or aluminum gaskets.

    if you dont want to spend the money on percys, run down to your local metal shop and buy some thick quality copper sheet, 3/16" should do nicely, and make your own using the stock gasket as a pattern.