Best way to remove exhaust manifold studs from cylinder head

[Danez]

Making a jig out of thick flat bar so you put it over a good stud and lock it down precisely over the broken ground flat stud helps in drilling & tapping out the old stump thread

genius idea that, hopefully it wont come to that but it's good to know

 

[DAPPH]

Brass nuts won't seize onto the studs.

I've had brass nuts on exhaust manifolds & flanges squeal because they were so tight and occasionally had them shear the stud they were on

 

[Red'n'Black]

I've had brass nuts on exhaust manifolds & flanges squeal because they were so tight and occasionally had them shear the stud they were on

Any time a fastener starts the dreaded squeaking or creaking on the way out, I stop, apply plenty of Plus Gas or similar, wait for it to soak in and then work it back and forth in quarter-turn steps, repeat until it comes out smoothly.

Trying to push on through nearly always shears them off in that situation IME. I'd also bin any bolt that gave me the 'creak of death' once I'd got it out, it'll be weakened and even more likely to break next time round.

 

[ms08]

Making a jig out of thick flat bar so you put it over a good stud and lock it down precisely over the broken ground flat stud helps in drilling & tapping out the old stump thread

I thought of this for mine as have one broken stud. Is it worth bushing the bar to give better guidance. Was going to see if an engineering shop could make one up.

 

[8ob]

I thought of this for mine as have one broken stud. Is it worth bushing the bar to give better guidance. Was going to see if an engineering shop could make one up.

When all else fails its the only way.

A question for the drillbitists

I need to drill out quite a large number of 8mm HT steel bolts that have become well and truly part of what they are screwed into, access isn't good and they will need centre drilling before drilling. What would be the best drill and centre drill for this job, don't mind expensive but it would...

www.mig-welding.co.uk

 

[Melvyn Best]

I have a Klan? type stud extractor that tightens more onto the stud as you turn it anticlockwise. Soaking the studs with a good penetrating oil for a while beforehand if possible , then giving them a few clouts on the end before using the extractor . I often use a 3/8” impact gun , the vibration helps. As already suggested the Rigid type extractor uses a guide over the stud to center any drilling operation if you go that route but why do they use a right hand drill bit ? Left hand drill bits will often remove stubborn studs as you are drilling. I have also had success using a freeze spray

 

[Smallfry]

Screw a nut on, but leave a little "cup" at the end, and mig weld it with highish setting. The heat should release it. Let it cool down and use a socket, although you might have to reshape the head of the nut a bit.

Cover the rest of the cylinder head to protect from spatter.

 

[DAPPH]

Use t

I thought of this for mine as have one broken stud. Is it worth bushing the bar to give better guidance. Was going to see if an engineering shop could make one up.

Use two flat bars coming in from different studs over the stud to be drilled out , to achieve the bushing effect. I used some 15 mm a 25 mm flat bar m put it on the good stud then used dividers to find the middle of the dead stud & transferred the measurement onto the bar . then used a pilot hole & an undersized drill to get down into the stud then use the rigid extractor to ease it out . I've also tapered a decent quality UNBRAKO ( sp) Allen keyy so it could be gently tapped into the newly drilled hole and undone such drilled studs that way .