Removing cylinder head bolts

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AndyB57
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Joined: 01 May 2019 20:25
Location: Ilfracombe UK

Removing cylinder head bolts

Post by AndyB57 »

The 4 bolts on the front cylinder head are proving very reluctant to loosen. I've used Plus Gas and heat numerous times but none of them are showing any inclination to undo and I feel I'm in danger of breaking something if I lean on them much more. Is the only answer to keep using the Plus Gas, heat and a longer wrench??
huub
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Re: Removing cylinder head bolts

Post by huub »

remove the allan screw in the pushrod tunnel
AndyB57
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Location: Ilfracombe UK

Re: Removing cylinder head bolts

Post by AndyB57 »

huub wrote:remove the allan screw in the pushrod tunnel
Thanks but I'm not at that stage yet.
trinder
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Location: Halesowen UK

Re: Removing cylinder head bolts

Post by trinder »

Try tighten, then loosen, old Fuzz Townsend top tip from Car SOS.
Steve Brown
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Location: Leicestershire

Re: Removing cylinder head bolts

Post by Steve Brown »

trinder wrote:Try tighten, then loosen, old Fuzz Townsend top tip from Car SOS.
This plus what Huub said. Loosen that M6 cap head first. Not that it loosens the main stud/nut set but it means less torque required to get the cap head out so less likely to round the socket.
For the main 13mm nuts try to get hold of a 6 point socket, less likely to round the nuts off. You won't do much damage if you apply plenty of force to loosen them. The worst that can happen is the stud may shear. I have plenty of those spare if that happens, FOC + postage!
I would avoid using heat there as I think it would be hard to target the heat exclusively to the steel bits. They shouldn't be too hard for a decent socket and wrench to shift them.
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72degrees
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Re: Removing cylinder head bolts

Post by 72degrees »

I did have one stud unwind from the cases because the nut was corroded on, but that's not too big a deal with the engine out. Possibly awkward with it still in and being unlucky which stud.

You could try 'shock 'n unlock' (freezing/penetrating spray) instead of Plusgas, though that works best with alloy/steel interfaces.

+1 on the recommendation for loosening the cap screw first than a 6 point or surface dive socket.

They are 'nyloc' nuts (well they are, and a new set each time on mine), so a fair amount of stiction if they were torqued up properly.

There eventually comes a time to fetch out the 'breaker bar' - though it may do as in says on the tin.
AndyB57
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Re: Removing cylinder head bolts

Post by AndyB57 »

Thanks trinder, SB and 72degrees - too wet for gardening, etc this afternoon so going to have a proper go at them with more oomph. I'll let you know how it goes.....
AndyB57
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Re: Removing cylinder head bolts

Post by AndyB57 »

Eased the bolts off! I can tell the Allen bolt could be challenging to remove with the engine in the frame though.......
3potjohn
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Re: Removing cylinder head bolts

Post by 3potjohn »

The allen bolt should be eminently removable with the engine in the frame. A magnet is useful if it drops down.That is assuming it cones undone easily going on your experience so far.
John
AndyB57
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Re: Removing cylinder head bolts

Post by AndyB57 »

3potjohn wrote:The allen bolt should be eminently removable with the engine in the frame. A magnet is useful if it drops down.That is assuming it cones undone easily going on your experience so far.
John
Planning to have a go tomorrow, hopefully it'll all be plain sailing and I can have a look at the valves then bolt it all back up.
Steve Brown
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Re: Removing cylinder head bolts

Post by Steve Brown »

AndyB57 wrote:
3potjohn wrote:The allen bolt should be eminently removable with the engine in the frame. A magnet is useful if it drops down.That is assuming it cones undone easily going on your experience so far.
John
Planning to have a go tomorrow, hopefully it'll all be plain sailing and I can have a look at the valves then bolt it all back up.
If you weren't already planning to do it, take the barrels off and replace the base gasket. 9 times out of ten if you remove the head then the barrel moves slightly-enough to break the seal and you'll have an oil weep to annoy you. If you are planning this, simply read back to the top and skip this message.
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72degrees
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Re: Removing cylinder head bolts

Post by 72degrees »

AndyB57 wrote:
3potjohn wrote:The allen bolt should be eminently removable with the engine in the frame. A magnet is useful if it drops down.That is assuming it cones undone easily going on your experience so far.
John
Planning to have a go tomorrow, hopefully it'll all be plain sailing and I can have a look at the valves then bolt it all back up.
I always stuff some paper towel or rag in to the pushrod tunnel while taking the socket head screw out, and when putting it back in. You won't forget to take it out because the push rods won't drop in until you do ;)
AndyB57
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Re: Removing cylinder head bolts

Post by AndyB57 »

I always stuff some paper towel or rag in to the pushrod tunnel while taking the socket head screw out, and when putting it back in. You won't forget to take it out because the push rods won't drop in until you do ;)[/quote]

Thanks - I took one look at those holes and then the Allen bolt, grabbed some paper towel before I did anything else!
AndyB57
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Re: Removing cylinder head bolts

Post by AndyB57 »

Excuse my ignorance, but having looked at various drawings I cannot for the life of me work out what the Allen bolt does! The pushrods on my engine can be removed with it in situ - does that mean something is missing if the bolt is supposed to secure them in some way?
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72degrees
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Re: Removing cylinder head bolts

Post by 72degrees »

AndyB57 wrote:Excuse my ignorance, but having looked at various drawings I cannot for the life of me work out what the Allen bolt does! The pushrods on my engine can be removed with it in situ - does that mean something is missing if the bolt is supposed to secure them in some way?
Helps seal the head gasket round the push rod tunnel. You can remove the pushrods, but you won't be able to lift the head until the cap screw is out.
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