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  1. #1
    Join Date
    Sep 2008
    Location
    pensacola, fl, us
    Posts
    180

    Default New manifolds/risers leaking?

    1995 454XL fresh water cooled (full system) I pulled engine in May for rebuild. Newer riser failed ( I think). Have to pull engine again for V-drive replacement. Today I pulled manifolds and risers on new rebuild with less than 5 hrs. Manifold on inboard side center two cylinders had evidence of water. What am I doing wrong?? I used paper gaskets (green ones) and block off plate CRU-98124. I applied thin coat of perfect seal to both sides of gaskets. tourge to 30 psi ( cant tourge inside nuts, just outside bolt heads) ran to operating temp 3 times, then re-tourged. installed block off plate with 'fins' up in riser. Ideas???

  2. #2
    Join Date
    Sep 2008
    Location
    Maryland - USA
    Posts
    6,761

    Default Re: New manifolds/risers leaking?

    any evidence in the exhaust passages of the manifold to suggest the leak source?

    not sure about the 'fins' on the plate.....picture?

    two things I'd check - make sure the gasket faces on both parts are flat (straight endge and feeler gauge) - if not, a machine shop can broach them if needed. the other is to find a way to torque the 'aft(?)' fasteners (offset crow's foot maybe) - unequal torque cant help...

    Don't see anything wrong otherwise....

  3. #3
    Join Date
    Sep 2008
    Location
    pensacola, fl, us
    Posts
    180

    Default Re: New manifolds/risers leaking?

    I have tried to put pictures up with no avail. I guess I should say elbows and not risers. My elbows are mounted right on the manifolds.

  4. #4
    Join Date
    Aug 2008
    Location
    Fairport, NY
    Posts
    1,624

    Default Re: New manifolds/risers leaking?

    Is it raw water getting in or coolant? If you don't know, then pressure test the system at the HE.

  5. #5
    Join Date
    Dec 2008
    Location
    Bourne, MA, USA
    Posts
    307

    Default Re: New manifolds/risers leaking?

    Kevin,

    I have used the graphite type gaskets without any sealant and they work very well. Those block-off plates are called wing plates and the lip does face up towards the elbow. It is suppose to catch and burn off any condensation that may form on the elbow and drip down towards the inside of the manifold. As you must know the manifold has antifreeze going through it and must be drained down before removing the elbow. If removing the manifold also then that needs to be completely drained before removing it so it may be necessary to remove a plug in the block to make sure no antifreeze gets into the exhaust ports when removing it. Why did you remove the manifolds to begin with?

  6. #6
    Join Date
    Sep 2008
    Location
    pensacola, fl, us
    Posts
    180

    Default Re: New manifolds/risers leaking?

    Raw water is getting in the new manifolds. I pull engine a few months ago for rebuild. Water got in #3 & 5. The risers were new in Jan. After rebuild, V-drive needs replacing so need to pull engine again, so manifolds and risers need to be removed for engine to fit out of hole. My first thought was new elbows were bad. But now I think the joint between the manifold and elbow is the problem. Where can I get the graphite type gaskets? All is get when I order them are the green ones (OSCO) OSCO says no sealant, but.....

  7. #7
    Join Date
    Aug 2008
    Location
    Fairport, NY
    Posts
    1,624

    Default Re: New manifolds/risers leaking?

    Quote Originally Posted by kevin_z View Post
    Raw water is getting in the new manifolds. I pull engine a few months ago for rebuild. Water got in #3 & 5. The risers were new in Jan. After rebuild, V-drive needs replacing so need to pull engine again, so manifolds and risers need to be removed for engine to fit out of hole. My first thought was new elbows were bad. But now I think the joint between the manifold and elbow is the problem. Where can I get the graphite type gaskets? All is get when I order them are the green ones (OSCO) OSCO says no sealant, but.....
    The green ones can certainly work. I have seen primer/paint on the sealing surfaces that needed to be dealt with by a putty knife. Thin layer of sealant is best, very thin. I used any of the "ultra" RTV's but nothing against perfect seal, or aviation seal, etc. I've tried dry, not as good.
    If you do break this down, take a steel rule and check for flatness by eye and a strong light and/or feeler gauges.

  8. #8
    Join Date
    Dec 2008
    Location
    Bourne, MA, USA
    Posts
    307

    Default Re: New manifolds/risers leaking?

    I recently had a brand new riser leak that I was installing with a new elbow on an 8.1L Crusader. While I was filling the system up the antifreeze was leaking out at the bottom of the riser. I also thought it was the gasket so I drained the system again and replaced the gaskets only to have it leak again. I eventually found that the riser had a breach between the closed cooling section and the mounting hole. Put the old riser (which looked good anyway) back on and buttoned the system up. My point being your new elbow could possibly be defective. I was fortunate that the leak was on the outside where I could see it and not one the inside.

  9. #9
    Join Date
    Sep 2008
    Location
    Maryland - USA
    Posts
    6,761

    Default Re: New manifolds/risers leaking?

    Erich's point begs the question - who's cast iron did you buy?

  10. #10
    Join Date
    Sep 2008
    Location
    pensacola, fl, us
    Posts
    180

    Default Re: New manifolds/risers leaking?

    The new manifolds and risers came from a place in Michigan. The manifolds have the Crusader flag on them and the elbows(risers) are the tall ones. They look 100% better quality than the OSCO that I put on in Jan. I did find the black graphite gaskets from the same place I got the manifolds and risers. They are twice the cost of the green paper ones. They should be here first of week. I'm going to mic the graphite and paper gaskets and see if there is a difference in thickness. I also found a 9/16" socket with single swivel to get the inside nuts torqued from snap on. It is a 1/4" drive, but can handle 30 ft pound.

  11. #11
    Join Date
    Mar 2015
    Location
    Deale, Md.
    Posts
    19

    Default Re: New manifolds/risers leaking?

    Run a flat file across the face of the manifold and elbow ..

  12. #12
    Join Date
    Sep 2008
    Location
    pensacola, fl, us
    Posts
    180

    Default Re: New manifolds/risers leaking?

    Got the black gaskets. Took all parts to machine shop. Everything was fine. Re-assembled risers (elbow) to manifolds filled coolant. Ran to temperature and re torqued. all appears good. Moral of story. Don't use nothing but the graphite gaskets with no sealant.

  13. #13
    Join Date
    Sep 2008
    Location
    Maryland - USA
    Posts
    6,761

    Default Re: New manifolds/risers leaking?

    glad that one is behind you!!

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