cylinder head bolt from hell. Help/tips needed.
#1
cylinder head bolt from hell. Help/tips needed.
I am doing a head gasket replacement on my wife's 02 disco (108k miles) and I've hit a brick wall. The LH head came off easily. I found that a deep 11mm socket and an 18" cheater bar were good enough.
I then started the RH side, unbolting in the order stated in the RAVE manual. The problem is I can't the the one out nearest the firewall, inside the head. I've used an electric impact wrench (extensions, U-Joints, 5/8 socket), a pneumatic wrench, a pneumatic rachet plus the cheater bar and socket, have tried tihtening it slightly first and hit it with an extension bar and hammer to break it free.
To date I've cracked 3 deep 5/8 sockets (using the cheater bar), am on my 3rd impact socket as they keep getting rounded, have cracked a sure grip socket designed to get bolts out and have completely run out of ideas as the head is starting to round off.
Any ideas would be greatly appreciated?
I then started the RH side, unbolting in the order stated in the RAVE manual. The problem is I can't the the one out nearest the firewall, inside the head. I've used an electric impact wrench (extensions, U-Joints, 5/8 socket), a pneumatic wrench, a pneumatic rachet plus the cheater bar and socket, have tried tihtening it slightly first and hit it with an extension bar and hammer to break it free.
To date I've cracked 3 deep 5/8 sockets (using the cheater bar), am on my 3rd impact socket as they keep getting rounded, have cracked a sure grip socket designed to get bolts out and have completely run out of ideas as the head is starting to round off.
Any ideas would be greatly appreciated?
#2
#3
#4
I've had similar problems... If I get stuck on the first bolt, I'll just reverse the order that I extract the bolts in and switch to the bolt at the other end of the cylinder head.
In the past, I've wasted a lot of time messing around with various flavors of bolt extractors, applying heat, etc etc.
Now-a-days, if I strip/round off the edges of a head bolt, I'll either drill or cut the head of the bolt off. The head bolt holes in the cylinder head don't have any threading so removing the head of the head bolt turns it into a stud that the cylinder head can be lifted off of when the other head bolts are removed.
If needed, stick a few old head bolts in a vice, and practice drilling out the heads. Take care to only remove material from the head of the head bolt and not the cylinder head etc etc. Use good carbide steel cutting drill bits. Use cutting oil/fluid, go slow, starting with smaller bits increase to larger bits. The drilling speed is very slow. Mark the bits with tape etc so you know how deep to drill into the head of the head bolt (you don't want to drill into the "shaft" of the head bolt).
Once you've removed the head of the bolt, it becomes a "stud" and you'll leave in place until after you've removed the cylinder head. Be careful not to gouge or scratch the face of the cylinder head, with the head bolt stud, when you lift it off the cylinder block.
After you've pulled off the cylinder head, if you use a dremel tool, to cut a notch in the top of the head bolt/stud, you'll be able to use a flat head screw driver to unscrew/remove it from the cylinder block.
Good Luck.
Thomas
In the past, I've wasted a lot of time messing around with various flavors of bolt extractors, applying heat, etc etc.
Now-a-days, if I strip/round off the edges of a head bolt, I'll either drill or cut the head of the bolt off. The head bolt holes in the cylinder head don't have any threading so removing the head of the head bolt turns it into a stud that the cylinder head can be lifted off of when the other head bolts are removed.
If needed, stick a few old head bolts in a vice, and practice drilling out the heads. Take care to only remove material from the head of the head bolt and not the cylinder head etc etc. Use good carbide steel cutting drill bits. Use cutting oil/fluid, go slow, starting with smaller bits increase to larger bits. The drilling speed is very slow. Mark the bits with tape etc so you know how deep to drill into the head of the head bolt (you don't want to drill into the "shaft" of the head bolt).
Once you've removed the head of the bolt, it becomes a "stud" and you'll leave in place until after you've removed the cylinder head. Be careful not to gouge or scratch the face of the cylinder head, with the head bolt stud, when you lift it off the cylinder block.
After you've pulled off the cylinder head, if you use a dremel tool, to cut a notch in the top of the head bolt/stud, you'll be able to use a flat head screw driver to unscrew/remove it from the cylinder block.
Good Luck.
Thomas
#5
I would put the other bolts back in the order the rave tells you to and torque them up just a little per the rave's order. Then try to loosen that bolt up, it seems like that should ease some pressure up on it. I also like wobble extensions because they allow the socket to stay flat on the bolt head while you're giving the wrench hell.
#6
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