Cleaning Exhaust Manifold heat riser face? (1 Viewer)

[SteveH]

I replaced these gaskets 20+ years ago on my '78 FJ40, and chunks of the OEM gasket are rust-welded to the face of the manifold. See photos. I have soaked them in PB Blaster and tried to lift the edge with a razor blade to no avail. Any other suggestions to remove this rust-bonded layer of steel? Thanks! Steve

 

[Pete]

I'd try Ed's Red (equal parts mineral spirits or paint thinner, kerosene or diesel fuel, acetone, and automatic transmission fluid) followed by scraping with a stiff putty knife or a wire wheel in a grinder.

Good luck,
Pete

 

[SteveH]

I've always wanted to make a batch of Ed's Red, so this is as good a time as any. Thanks!

 

[Spike Strip]

I had to use a die grinder with a very mild abrasive wheel and a light touch. That's what MAFs engine builder told me to do .... He also said to use a smear of the High-temp Permatex to help out the next guy (unless you do it again in 20 years )

 

[SteveH]

I tried a blue 3M Scotchbrite wheel and that removed the top layer of crud, but not this. I might tap/kiss this with a carbide burr and see if I can upset it enough to flake it off in smaller pieces.

Before reassembly, I was thinking of coating it with anti-sieze, but maybe a very high temp Permatex is the way to go. Obviously, 20 years of moisture/condensate/heating cycles are the cause of this.

 

[Spike Strip]

The common *wisdom* on MUD said that the orange hi-temp RTV would not hold up on the manifold. I used it for the mating surfaces between the intake/exh and on the rings for the swivel horns. 5 years later it's still the original orange color and has held up just fine.

The machinist I went to uses it on every combo he rebuilds, Land Cruiser and other models.

This pic is after I cleaned with a stone and then polishing disc.

 

[John Smith]

You're asking for trouble with that flapper held on with one fastener. Both mine rusted away, and I ended up with that plate blocking my exhaust manifold, which caused overheating of the engine. Took me forever to diagnose that one. I would step up to a flap wheel on the angle grinder to remove that old gasket material. I'd probably try the red Roloc first though.

 

[Tools R Us]

Use the round end of a ball-peen hammer, tap/hammer on it, starting at an edge. The vibration/impacts will break up the rust holding the metal gasket on.

 

[65swb45]

Use the round end of a ball-peen hammer, tap/hammer on it, starting at an edge. The vibration/impacts will break up the rust holding the metal gasket on.

I have had mixed results with this method, but it is still my first choice. And you definitely want to try this before adding liquid penetrants to the equation.

 

[SteveH]

Thanks for the advice - I tried this: a sharpened cold chisel at just the right angle peeled back the metal. After that, I tapped the chisel endwise on the rusty flakes, and those popped off. A wire cup brush and a Scotchbrite disk did the rest.