well i replaced my elbow...------WebKitFormBoundaryOgKxyu+xYPALK6+O

Posted By: carey mitchell------WebKitFormBoundaryOgKxyu+xYPALK6+O
Date: 2/26/08 5:53p.m.

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In Response To: S26 - mixing elbow replacement (mike)

well i replaced the mixing elbow on the yanmar 2GM20 F a year ago.after 7 years there was significant carbon buildup. the 1st thing to do is look for all the various exhaust hoses etc that are attached. any thing that will block your access to the mixing elbow must come off . Mark all the stuff you have to remove , hoses lines and the like. take a digital camera picture if you're not sure of the s et up. with blue #m painters tape , mark and write down which hose piece connects to which. you may also have to remove the coolant overflow hose etc.-- be sure to write a list of every thing you're going to disconnect, (And put the bolts/nuts/screws into little plastic bags.) when you have a totally clear work area and can get to the exhaust elbow itself you will see it connects in 2 places: 1 end to the heat exchanger where the cool h 2 o flows in, 1 end to the engine where the exhaust gases come out of the exhaust valve. on the 2Gm you will see 4 bolts that holds the elbow to the heat exchanger. plan to remove the 4 bolts and take the elbow/manifold off in one piece, you will need a long crowbar and a vise stand to get these apart. a tricky part of the yanmar exhaust is that one of the ends of the mixing elbow is REVERSE THREAD ie left is tighten not left is loosen. this was done so the elbow does not vibrate loose... in any event it is a total #$%^& to get the elbow loose from the manifold til you figure this out... i soaked the elbow/manifold union in PBT descaler for 48 hrs and it still wouldnt break loose until i put it on a commercial shop vise. (be careful you dont want to break the manifold piece.) my advice is -- call mack boring t he east coast distributor for yanmar. ask to talk to Tom Watts in the tech department and give him the serial # and year of your engine -- ask him what parts are reverse threaded... i think it's elbow into manifold not elbow into engine... email me at cmitcpghpa@aol.com if you have more ?s... ------WebKitFormBoundaryOgKxyu+xYPALK6+O