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Oops. I expected this and certainly knew it was a bad idea to rush this in between work meetings.
I took one of the front water neck bolts out, it was heavily corroded. I let wd40 (i know I need something better) soak in for several days on all bolts, but it was still difficult to take out. The second bolt snapped unfortunately.
These are the bolts that hold the upper portion that is connected with the water hose to the part that sits between the block and this elbow part.
By looking, i assume nothing is lost as of yet because the sheared bolt is stuck in this lower part and not the head itself. Still, I'd rather not grind off the elbow to get at the two bolts that connect the lower part to the head. Additionally, i really want to avoid a repeat of this when I get to the lower two bolts that are bolted to the head.
Looking at my pictures, what do you reckon is the best next move? I dont have a welder and no electricity at the garage.
Drain the coolant and remove the water neck. I dont think the water neck itself has threads, so it should lift off leaving the broken bolt in the head (but it might be stuck to the gasket). See if the broken bolt is protruding past the head enough to get a vice grips on it. If so, soak it again in PB blaster/WD 40 and if possible, heat up the head area around the bolt (so it expands giving the bolt more space to come out and break through the corrosion). From there see if you can back it out with the vice grips.
If not enough of the bolt is protruding past the head, it will need to be drilled out and helicoiled. Helicoils come as a kit that gives you the needed tap and oversize drill bit. Youll need to determine the original bolt size and pitch and get the corresponding helicoil kit to match. It is luckily not in a very difficult spot to access with a drill, so thats one positive.
That is a two piece water connection. It looks like the bolt is broken off in the lower piece, not the head. The lower adapter can be removed from the head after you remove the outlet.
Thanks, it was indeed just stuck in the lower piece. Removing the hose made the lower bolts accessible. Copious amounts of lubricant, waking the bolts up, small movements back and forth, and hand-loosening the bolts did the trick. They came out without an issue.
The broken bolt is still stuck in the upper piece, and my set of broken bolt extractors only starts at size 8 which is too big. Can't grab the bolt, so I guess drilling or taking the piece to a welder is my next bet.
I also noticed the water pipe the neck is attached to is very corroded at the ends, might need to replace that too.
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You're lucky not to have an extractor in that size. They can break off and make the problem worse. The good news is that piece is easily replaceable -- so not a high stakes job trying to repair it. You have a unique opportunity too because you can drill it from the bottom side, which is the loosening direction. With any luck, if you drill from the bottom, the broken piece might turn out after all. Lots of ways to go about it, but I'd flip it over and put it in a vice, then fill the hole with penetrating oil (pb blaster, wd40, etc.) and let it sit over night. That alone might be enough the oil is perfectly positioned to penetrate (unlike most stick bolts where you have to rely on a wicking action). If not, I'd then put a short m6 set screw in the bottom and use it as a drill jig.
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Use the biggest bit that will fit into the hex recess to keep it centered, then drill through the set screw and into the broken bolt. With any luck the broken bolt will spin out. If not, you have a nicely centered hole in it you can use to center the bit needed to drill it all out and help-coil it. Hell-coils in aluminum are stronger than the original threads.
As for the neck, if you can sandblast it to start, that will give you a good sense of what you're working with. I had one on my old Mercedes that was seriously pitted and used this JB weld technique. It's been leaking free for the last 5 years at least,,,
With the part removed as your pictures show, heat is your friend. Alternately heat and cool the assembly with a torch. Propane is likely enough. The differential expansion will help break a serious corrosion bond, and removal of the stub will be a lot easier.
Use a penetrating lubricant on stuff like this prior to disassembly if you can possibly manage it. I keep aero Kroil, and use a 50/50 ATF and acetone blend in a pump oil can for cases where I can rely on it wicking into a thread over time. The acetone flashes off in the oil in the pump oiler over time, so I just need an ounce or two of acetone to rejuvenate the mixture a little. Multiple applications over time can be more effective, whichever fluid you use. PBblaster is on the local WalMart shelf in a pinch.
On older projects that haven't been treated to the best care, especially with poor coolant history, using an impact driver to loosen the bolts is often a saving practice. The blow from the hammer on the driver, combined with the twisting, is often just what you need to break a galvanic corrosion bond between dissimilar metals, or even with similar metals where coolant flow might be the cause of a potential difference from pieces further away in the system. Use a 6-point impact socket or impact-rated drivers, and the torque shock stands a better chance of reaching the threads.
There's never too much good to be said for using anti-seize compounds when working on parts like this. The bolts and the fitment faces deserve at least a thin film of anti-seize prior to assembly. On the faces, you can wipe off most of it with a paper towel before it goes back together. For bolts into blind holes, a similar thin film is needed to avoid hydro-locking. Care with where the stuff goes is important, but that same care will share back pretty generous rewards when you take it apart the next time.
In many industrial and particularly in marine applications, strategically placed sacrificial anodes are placed to supply the ions in an otherwise ion-starved liquid flow. For our cars, absolutely religious cooling system care is usually sufficient. Remember that the manufacturers' original service interval recommendations are there to allow something to last through the original warranty period at a low cost to the covered purchaser.
Thanks for the assistance! I can't put a set screw in because apparently the bolt didn't really move when I tried to take it out. There's no space to put the screw in and use it as a jig. I did turn it over and put creeping oil on the piece after submerging it in the stuff.
Took a drill and had a fairly centered hole. I however have trouble removing the last mm of the bolt, even after using the largest drill that would not delete the threads. I used an induction heater to heat the piece but that didn't do much. Didn't get it red hot though (not sure my cheapo heater can do so, it keeps cutting out).
Tried drilling and hammering the last screw pieces out but no real avail. It's almost out so I took a m6 and then m8 thread cutter tool, but probably messed it up since the tool fragmented and is now a bit stuck in the hole. Think it also deleted a bit of the threads.
Should I get a m8 metal drill and then helicoil it?
I ordered a helicoil kit. But because the M8 thread cutter tool was stuck, I tried drilling that out first. Turns out it's pretty hard. I messed up the hole which is now a bit more oval. I then proceeded to try and clean the neck part. Tried to polish it with a dremel, didn't do much. The sanding attachment did a bit too much.
Hell-coils in aluminum are stronger than the original threads. 