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!989 Exhaust Manifolds

Discussion in 'Ford Trucks' started by MickiRig1, Nov 28, 2006.

  1. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    On a 5.8 L --351 engine
    Anybody do exhaust manifolds lately? I got mine off after a 2 day fight and parts chase. I found they have no gaskets. Just metal to metal mating. My manual says to use graphite grease on the mating surfaces. This sounds really " JuryRig ". I am torn between using the gaskets I have and going the book route. What do you guys think? At least if I have to revise sealing the bolts will be a lot easier to get off this time.!
  2. jeh250

    jeh250 Junior Member
    Messages: 9

    For what it's worth: The only reasonable way to R&R manifolds, at least on the 460, is from the wheel well, through the inside fender. But you have probably figured that out by now. I have always sucessfully used gaskets, especially on "seasoned engines". Be sure to re-torque manifold bolts after a couple of warm-up cycles.
  3. B&B

    B&B PlowSite Fanatic
    Messages: 12,777

    Dont waste your time with the gaskets.Her's what I do...Make sure the two mating surfaces are spotless, I use a 2" scotch brite pad on a right angle die grinder to clean the surfaces really good.Then using Permatex "Ultra copper" hight temp RTV lay an 1/16 in. bead around each port on the manifold.Let it set for about 15min. until the RTV skin's over.Then install the manifold as usual.Torque the bolts to factory spec.
  4. MickiRig1

    MickiRig1 PlowSite Veteran
    Messages: 3,617

    Well, I installed them.I even found a replacement EGR pipe for it in my parts chase. I cleaned the surfaces with lacquer thinner and steel wool. There were all shiny and clean when I removed the old ones.
    I put a thin coat of graphite grease on the manifold surfaces. I used the red thread sealer / lock tight on the bolts and studs. Started it up and oH MY GOd it's a lot more quieter. I had 2 dime size holes in the left, a crack all most around on the right manifold with a quarter size ( EGR pipe ) hole at the north end. The worse part is that once the exhaust manifolds were not leaking. I found that an air injection pipe at the back between the 2 heads is rusted out and leaking exhaust ! It should pass emissions testing I can smell the Cat working well.
    Last edited: Nov 29, 2006