cast iron engine cover braze repair

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Cat dozer- Mitsubishi engine??? Its a DAMM SHAME!!Pics show broken area. A stub shaft that is the spindle for an idler gear that drives the oil pump (thats a mouth full) broke the bore in the front cover.Pre/postheat 600 degrees, OA braze with low fuming bronze, machine to size.Peter Attached Images
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Reply:Now that's a nice repair. Have one of these! Fire!, Fire! Oh wait, that's my torch...Lincoln PT-225 TIGLincoln 175 MIG
Reply:Great repair. What caused the casting to break originally? Did the idler seize or just weak casting/design? The bronze should hold up well.
Reply:Originally Posted by VipernutNow that's a nice repair. Have one of these!
Reply:Mitsubishi has supplied engines for most small-medium Cat excavators for years. Don't know about other Cat equipment.
Reply:Alright,  I've got a question for the braze master.  I had 4 hole flange on a cast iron eductor that had a missing corner.  Most of the bolt hole broke with it but some was left.  I made a new corner out of steel (not a very important repair) and brazed it on.  The trouble was, despite the use of pilot hole and stepping up drill sizes I couldn't prevent the bit from walking into the bronze.  I ended up having to drill the hole out about 1/16th oversized, refilling it completely with bronze, then redrilling again in the correct position.  Your repair is similar, half is bronze and half is iron.  How did you reform the hole?  In a mill?Even worse than using Mitsubishi engines, CAT is starting to outsource some of their critical engine bolts.  We recently experienced a failure of a head bolt due to a manufacturing defect.Last edited by 76GMC1500; 04-11-2010 at 12:01 AM.
Reply:Beautiful Repair CastWeld....I've done a similar repair on a guys Mower... but never seem to achieve the Nice 'FULL and SOLID' look of yours...  Any tips on preventing POCKING and PITTING when building up the BRONZE ??  Do you use a LOT of FLUX between LAYERS?Cheers,/J...Miller Diversion 165120 amp Buzz BoxVictor Oxy/Ace Oxy/LPGSmith "Little" Oxy/LPGHypertherm Powermax 30Lot's of Misc. tools n' crap....
Reply:Originally Posted by 76GMC1500Alright,  I've got a question for the braze master.  I had 4 hole flange on a cast iron eductor that had a missing corner.  Most of the bolt hole broke with it but some was left.  I made a new corner out of steel (not a very important repair) and brazed it on.  The trouble was, despite the use of pilot hole and stepping up drill sizes I couldn't prevent the bit from walking into the bronze.  I ended up having to drill the hole out about 1/16th oversized, refilling it completely with bronze, then redrilling again in the correct position.  Your repair is similar, half is bronze and half is iron.  How did you reform the hole?  In a mill?Even worse than using Mitsubishi engines, CAT is starting to outsource some of their critical engine bolts.  We recently experienced a failure of a head bolt due to a manufacturing defect.
Reply:Originally Posted by jmanBeautiful Repair CastWeld....I've done a similar repair on a guys Mower... but never seem to achieve the Nice 'FULL and SOLID' look of yours...  Any tips on preventing POCKING and PITTING when building up the BRONZE ??  Do you use a LOT of FLUX between LAYERS?Cheers,/J...
Reply:Originally Posted by castweldThanks   If you over heat the part your brazing it will make gas bubbles in bronze filler. Over heating filler will also cause problems along with dirty metal. Sometimes if I use too small of a welding tip I tend to get too close to base in an attempt to get enough heat heat into part. This, having inner cone of flame touching work causes me porosity probs. I get surrounding area red before bringing area to be brazed up to temp.  No flux after tinning- first layer.post pics maybe I can helpPeter