Join Date: Jul 2015
Location: Chicago SW suburbs
Removing AIR pump check valve from manifold pipe
I'm trying to get my exhaust manifolds off, and have run into a bit of a hiccup thanks to the wonderful AIR pump system. I was able to get the fitting from the pipe to the manifolds to loosen without issue on both sides, so I just detached the hose and spun the whole thing off on the driver's side, check valve still attached. But the passenger-side is a bit more challenging, since there's about a 3 or 4 inch length of hard pipe before the check valve -- even if I remove the oil dipstick tube it will interfere with the valve cover after about 270 degrees of loosening.
Even with a Kroil soak I can't get the thing to budge, in fact it's starting to round the corners. The service manual doesn't really show (in fact, looks like some of the graphics show the previous style exhaust manifold from before late-95), the Haynes manual has even less information, and I can't find the answer in any previous threads other than "delete the whole thing"
I need a sanity check: It is the "nut" with a 1" hex, that should be loosened from the fitting on the pipe connecting to the exhaust manifold with a 7/8" hex, right-hand thread, correct? Am I supposed to torch the thing or use flare wrenches instead of open-end wrenches?
Never mind, of course it is. I just needed to give the Kroil some more soak time. Definitely going to replace those check valves while I'm at it, took a little bit of paint off of them and one had some burnt crap (carbon deposits, presumably) in the exhaust side.
1996 Chevrolet Impala SS - Dark Cherry Metallic (77U/WA9800)
Stealth bolt mod, 2.5" X-pipe with Pypes Street Pro mufflers & Dynomax resonators, WeatherTech side window deflectors, Hayden 678 "tertiary" transmission cooler & Magnefine inline filter, 9C1 power steering cooling loop, otherwise completely stock
2000 Ford Explorer XLT 4WD (4.0L OHV V6) - Amazon Green Metallic (SU)
2018 Toyota 4Runner TRD Off-Road Premium - Nautical Blue Metallic (8S6)
Last edited by AP9; 08-10-2019 at 08:51 PM.