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In the process of replacing the water pump, I sheared off the M6 bolt at the 6 oclock position of the water pump. Heavy corrosion. Anyway, got the pump off and saw that enough threads were remaining for a pair of vice grips. Sprayed penetrating oil and waited.. Attached vice grips and tapped with hammer and it didnt budge.
I consulted the forums and it looks like heating with MAAP gas torch and wicking wax into the fastener works for stuck bolts like this.
I also saw a solution (generic youtube vid) where someone TIG welded a nut to a stuck stud like this and wicked wax into the fastener.
Wish I didnt bung up the threads or I could thread on 2 new M6 nuts and use that for leverage.
Has anyone tried the welding approach with an engine still attached to the car? I TIG weld, but nervous about welding on an engine because 1) there is fuel in proximity (more than a foot away) and 2) the ECU could get fried. I could attach the ground electrode to one of the other water pump studs to keep the electrical current limited to the WP area. Also, disconnect the ECU for safe measure. I could also use the welders blanket to cover as much as I can on the block and fuel rail.
Maybe Im overly concerned, but I dont want to blow myself up as Ive never welded on a car like this. I dont even like welding on exhaust pipes due to the proximity of the hard fuel tubing proximity. I am hoping all the you tubers are correct and the added heat + wax approach works.
Okay, this has worked for me in the past. Weld a M6 washer to the remainder of the stud and then weld a nut to the washer. I've welded on plenty of vehicles with out so much disconnecting the battery. With that said, I would remove anything electronic on my car before I started welding on it. I would have a fire watch man standing by with hose ready to go. Good luck, you should be fine.
Thanks for the advice guys. I will try the weld technique. I did find a FACOM stud extractor (FA-287B.6) for m6 bolts on amazon. I will use that as a back up if the weld trick doesnt work. Ill try to tackle that tonight and report back.
You might want to do a youtube search for welding a broken Subaru camshaft bolt first and or other videos. - Don't know for sure if they are applicable but some are emphatic about grounding your welder in a certain way or you'll fuse the internals of the engine.
Thanks for the heads-up Padhammer. Ill take a look. I bet the problem that you mentioned has to do with the current from welding going across bearings. Thats a big no-no as youll pit out and arc the races and rollers.
Im planning on cleaning up the closest of the water pump studs really well and grounding to that. I want the current to just go across the block adjacent to the pump. Ill disconnect the DME and other battery post as well so at least I wont fry the DME.
I do have high frequency start which is reeks havoc on electronics without good ground.
Wish me luck!
Originally Posted by Padhammer
You might want to do a youtube search for welding a broken Subaru camshaft bolt first and or other videos. - Don't know for sure if they are applicable but some are emphatic about grounding your welder in a certain way or you'll fuse the internals of the engine.
Well I welded the fastener unsuccessfully. At first, my smperage was too high and burned through the nut. I dremeled it off and tried again. After 3 attempts of too little power (and poor weld) I finally got a successful weld. I wicked wax in the threads and rocked the bolt back and forth. I thought I was making progress, but I ended up breaking the bolt off flush with the hole.
I guess Im going to try drilling out whats left and if I bung up the threads its helicoil time. I need to get a right angle drill due to limited clearance (about 7" to from water pump to radiator).
Im bummed as I gouged part of the water pump sealing surface and still havent removed that fastener. Really kicking my ****...
I've welded on the body (battery box) without problems, though I did disconnect the battery and DME/KLR out of an abundance of caution. I've tried welding nuts to coolant-corroded studs twice and had the same experience both times. Once the bolts are that bad, it's like welding to a piece of chalk. They just crumble even if you are able to attach the nut. It was worth a try though. I'd probably remove the radiator to drill it, and resign yourself to heli-coiling it (which is an upgrade to the soft aluminum threads anyway), though you might get lucky with a reverse drill bit and very steady hand. You can try center punching the stub and drilling by hand, or make up a jig from the old waterpump or scrap metal to ensure the hole is exactly where you want it and straight. And mark the bit so you don't drill too deep!
Use your existing waterpump as a guide to drill out the broken bolt. I also like to use a brass spacer that's just slightly smaller than the OD of the hole as a guide for the drill to help keep it perfectly centered.
Thanks for the advice. Ill remove the fans and radiator. Good idea on the water pump guide and marking the bit. Getting it square, centered and correct depth is critical. Ill report back on my progress. Ill probably take a day off to clear my work space and my head. This bolt is a real bugger.
Ive had luck using JB weld to fill in gouges in sealing area. I was planning on doing the same on this although I dont know how well it works on water pumps. I was going to coat the new gasket with indian head and button everything together. You could imagine my excitement when I saw that I damaged the seal area of the block.
How bad is the damage to the sealing area? If really bad, you could TIG in a little blob and file it flat with an oil stone. When you file the oil pump surface, you realize just how soft these blocks are. That said, unless you REALLY gouged it, the gasket with a little goo will hold up just fine... I use just the dry gasket and even that manages to hold tight with a less than perfect sealing surface...
The gouge isnt bad IMO. Ill get a pic tonight. I was thinking that RTV or indian head could probably fill that gap. Frankly, my welding skills arent all that great to get a good bead on that block.
I've had good results with a left-handed drill bit. Once you get the tension off the threads, it should come right back at you..This is a good technique on spark plugs too, as it minimizes the amount of chips that go into the cylinder. .02 cents. Thanks.
08-15-2016, 12:51 PM
Another broken bolt at water pump - weld fix?
