Mike C.

Have you tried putting a vice-grip on it? If you can get a good bite and have room to turn it something will give. One other idea might be to remove the other studs so the pump body can rotate a few degrees in each direction (I can't remember how much room is in there). That may be enough to either break the corrosion or the stud. Either way you're going to replace the studs. Good luck.

944Ross

Ditto on the vicegrips. If that fails, do you have a MIG welder or a OA torch? Thread on the nut and weld it. You might even try threading on the nut and f#$%^& up the threads on the end so the nut gets jammed. Then unscrew it.

Like Mike says, something's going to give, might as well get on with it!

Mark944na86

I hear you all about how that studs going to be replaced anyway, the ony reason I'm going tentatively is I'd really like to avoid breaking it in or at the block so I have to get a fancy extraction tool in there to get the rest of it out. Although I may just have to man up and swallow hard and go with the vice grips or similar and see what happens...

Interesting problem, though.

m73m95

I broke a stud off in the block (so corroded, it broke with nearly no pressure at all), then promptly broke the extractor off in there as well.

10 hours, 4 drill bits, 3 carbide cutters, and 2 pints of blood later, its like brand new!

Whatever method you decide on, use LOTS of penetrating oil, and work it back and forth to avoid snapping the studs off.

luftpirate

944Ross

Then your best plan if the fear of breaking the stud is so great, is to sacrifice the wp. Get a hole saw about 3/8"-dia., and buzz thru the front part of the casting around the stud. I'd be surprised if the rear casting surface is what is holding it on, but at least you'd have access to scrape the crap off the stud.

Mark944na86

LOL -- that's hilarious.

I've actually ordered a variety of hole saws off eBay, so if I haven't got this thing off by the time they arrive, it may be time for Plan B. Preserving the WP is a not a great priority at this stage -- the return core deposit is not worth that much on it.

In the meantime it's been mostly scrape, oil, wiggle, leave for few hours, repeat. Mostly I'm going slow because ideally I'd like to get the WP clear of the stud before trying to remove the stud from the block to replace it -- a two step operation strikes me as less likely to lead to the situation of my cartoon persona above.

944Ross

You might try very hot water, deposits from the cooling system are more likely water soluble than in penetrating oil.

Joe Jackson

You'll do a lot less damage if you simply pry a little harder behind the pump to dislodge it from the stud. Those studs are so long and such a small diameter, that it will likely break off at the block (creating a new, more annoying problem) if you did manage to get something on the end that allowed you to turn it with some force. Those studs are Loctited in at the factory and will require heat for removal. You won't be able to direct enough heat where it's needed with the waterpump in the way.

In your first pic, right below the camshaft sprocket you can see a tab on the pump casting. That tab is there to pry the pump off the block. Give that another try. It's by the far the easiest, cleanist, and in my opinion, most likely to work method.

Barry Lenoble

Hello,

IMHO, to remove the WP from the stud you need to break the bond of the corrosion. I think the best way to do that is with hot and cold. Put a torch on the WP and get it hot. The metal will expand and that will break the corrosion. Then spray the stud with a cold spray. That should break things loose for you.

Barry

Mark944na86

It's off! The method was digging away between the stud and the WP housing with a dremel-like tool and a small (1/16") HSS bit. And soaking with penetrating oil between sessions.



The back of the pump (the case casting mark says it's a 98 casting... I believe this pump was new when put on by the PO). Below the pump is the dremel-like tool:



I also used one of these 90 degree drilling attachments... the dremel-like tool was easier to use to get in there, though.



This is close-up of the hole showing the drilling from the front:

Mark944na86

Now, I've just got to consider what to do, if anything, about the studs that are in there (except to clean them up, of course.) The corrosion seems reasonably superficial, and they are all solid in the block.

Perhaps just clean them up and apply a coating of anti-seize on them before reinstalling? Or should I really get these all out and reinstall some new studs?

Darwantae951

Wow, makes me wonder when the last time it was changed.

luftpirate

If you try to remove them you risk breaking them off in the block. For some reason some of the bores go through into the water jacket so the end of the studs rust and makes it very difficult to remove them. If you have to remove them I would advice hitting them with a good penetrant over several days and shocking them before attempting it. I don't know enough about these cars to say if you will run into issues re-using the studs but if you chose to be careful not to over-torque them.

944Ross

The studs really don't have huge loads on them; the point of having so many bolts/studs is they apply a uniform pressure to give good gasket pressure. I'd clean and preserve.