Which ?

[slack ma girdle]

The last bolt on my water pump is stuck fast, and as a result of my efforts is nicely rounded

Should i:

Weld on a bigger nut (Not sure hoe i am going to hold the nut on until it is tacked on)

Drill out the middle and tap in one of those star shaped stud remover

[felixthelogchopper]

I had a similar problem with an alternator bolt on my Mazda. I got a set of Irwin sockets from Screwfix which bite into the rounded-off head until it starts to turn. They cost me about £25 and were worth every penny

[agg221]

I'd find a nut that just fitted on the rounded over corners and plug weld it on. Fitting over the corners will hold it in place to tack weld, and it will be big enough not to be too likely to round off once it's been annealed by the welding. The heat will also help to free off the bolt, although wait until it's cold again before trying as the bolt will expand when hot, making it a tighter fit, and then become slightly more free once cold. If it shears off you can do it again - if you go down the drilling route and it goes wrong you're really stuffed.

 

Alec

[Goaty]

Have you tried a little heat if possible, The weld heat may help. Sometimes Ive reshaped the head square and suceeded. Still an infuriating waste of time, Maybe if the head came off and the pump you could get the stud remover on. I 2nd agg221. He typed faster!

[Mesterh]

Never ever bother with a stud extractor, they dont work unless the stub is proud.

[robbo 110]

find a tight fitting SIX sided socket, this stuff is amazing. wurth rost off ice rust releasing agent cracks rusted joints 400ml top product | eBay

[predator]

The last bolt on my water pump is stuck fast, and as a result of my efforts is nicely rounded

Should i:

Weld on a bigger nut (Not sure hoe i am going to hold the nut on until it is tacked on)

Drill out the middle and tap in one of those star shaped stud remover

 

IF ITS A BOLT

 

just grind the head off and twist pump about get it out the way then remove leftovers

[Tyz05]

As agg221 said:thumbup: whats it on out of curiosity? Whats the access like?

[pleasant]

A few years ago I purchased a set of those super wrenches that are sold on Ideal World. We often get numpties rounding off blade bolts and we used to end up welding a good nut to the old. I looked at these being demonstrated and thought I would try them. I can tell you they are brilliant for removing rounded off/damaged bolts/nuts. Three years of owning them and we haven't had to weld a nut on since. Would certainly recommend them.

[slack ma girdle]

Cheers for the replies peoples. I ended up drilling out the head, to leave the stud. Removed the water pump, and used a stud extractor with a 2' extension bar to shift the ruddy thing.

Heat would have not helped as the bolt is 5" long.

However the tip of the bolt about 1/16" is still left in the enginne block, so i will have to pack the new bolt with a couple of washers.