Should a rookie try to weld on a cast iron pump

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I have an old Ford tractor that the hydraulic pump has a hairline crack where a manifold bolts to it, and is dripping fluid, my question is should a rookie attempt  this weld ? Can it be mig welded or have to be stick? From what I have seen on buying rebuilt units they are pricey 500-800, I will lose the core credit of 100 if its welded on , is it worth a shot at repairing? ThanksLast edited by mxpapa; 06-13-2014 at 12:10 AM.Thermal Arc 210 - Tweco 211I - Cutmaster 52
Reply:You will ruin it.  The body is likely cast steel, cast iron, or a malleable iron.  By the time you weld it you will have warped the housing. Whether it is a gear pump or vane pump the warped housing will ruin the running fits inside.  Likely if you did not preheat  enough you will crack it again.   Consider it non weldable.
Reply:If you disassemble the unit and can build a fixture to hold it in place you can. The cracked piece can't move. Drill out both ends of the crack and clean thoroughly. Pre-heat the part to the required temperature for the type of cast it is. Depending on the size of the crack you can probably get a good bead/fill with 3/16 nickel rod in the groove you have previously cut in the crack. Use a good quality burr so you don't imbed/impart a lot of foreign contaminants in the repair. Your going to want to normalize the weld so it's all the same temp and then cool it slowly. Peen or Pien the part/weld as your cooling it. Remember to maintain a fairly constant temperature so it doesn't cool too fast. So.......in a nutshell, no, this isn't a newbie job. You are going to ruin the part. Clean the crack and fill it with a suitable epoxy. When you get time find an old engine block or something cast and break it. Weld it back together. I recommend oxy/acet. with brass filler. Buying nickel or cast rod is an investment. Good luckArcon Workhorse 300MSPowcon 400SMTPowcon SM400 x 2Powcon SM3001968 SA200 Redface1978 SA250 DieselMiller Super 32P FeederPre 1927 American 14" High Duty LatheK&T Milwaukee 2H Horizontal MillBryan
Reply:How hot does this pump get? why not fix it with bronze (i.e., braze it). You will be better able to manage the heat input this way and if the pump doesn't get too hot, brazing is as strong as welding.Miller Multimatic 255
Reply:Check these out  http://www.twi-global.com/technical-...-of-cast-iron/http://www.antiqueautoarchive.com/fo.../blockweld.pdfMiller Multimatic 255
Reply:JB Weld it.
Reply:Hunt up a replacement. If it is already leaking, the crack has gotten to an oil passage or two.You'll be fixing it every year until then.I've been keeping some 'old iron' going for many years. Some things are just not worth repairing.Be wary of The Numbers: Figures don't lie,. but liars can figure.Welders:2008 Lincoln 140 GMAW&FCAW2012 HF 165 'toy' GTAW&SMAW1970's Cobbled together O/A
Reply:People do not understand that the internals of a hydraulic pump are machined to very tight tolerances.  After repairing with heat, it is all over.  Yes you can repair an engine block with a cracked water jacket but don't expect to slap it back together and run it if the cylinder surfaces reach red heat.  The manufacturer goes to great lengths to produce a product that often has tolerances in the tenths of thousandths of an inch.  Repairing with heat just screws things up.  Tolerancing on modern equipment is to tenths of rather than thousandths unlike fifty plus years ago.  If this is an old gear hydraulic pump running low pressure and made in the 1950's go for it.
Reply:Hey thanks for the replies, I can understand the fixing of a cylinder block, thanks for making me think of the pump tolerance, I will try the jb weld, hadn't considered that yet and its not a high pressure leak might work. You know just trying to find excuse to weld the sucker.Thermal Arc 210 - Tweco 211I - Cutmaster 52