Head Bolts not moving

Knightspirit

Well-known member
Sep 22, 2019
251
84
Mount Shasta, CA
I was attempting to remove the cylinder heads on my 4.0 donor motor which I am still deciding what to do with. Thought I would open it all up and see what condition it's in. When I got to the heads though - I couldn't get the first bolt out. I have so far broken three sockets! Just ordered a snap on - but was wondering what is the best method to get these bolts out? Impact wrench? Heat? Hammer? The manual suggests a pretty low torque value - starts at 15 lbs and then two 90º turns - so they must just be stuck.

The manual also mentions "lifting eye to cylinder head bolts - 30 lbs." What is that referencing?

Cylinder head - remove
  1. Remove rocker shaft assembly.
  2. Mark heads LH and RH for reassembly.
ENGINE
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  1. Using sequence shown, remove and discard 10 bolts securing cylinder head to cylinder block.
  2. Release cylinder head from 2 dowels and remove cylinder head.
  3. Remove and discard cylinder head gasket.
  4. Repeat above procedures for remaining
    cylinder head.
 

Tugela

Well-known member
May 21, 2007
4,754
562
Seattle
Here's what worked for me:
  1. Impact socket on a 1/2" drive breaker bar
  2. Bottle jack handle over breaker bar as extension
  3. Get someone else to push the socket firmly down onto the bolt head
  4. Use both hands to slowly pull on the extended breaker bar in a plane perpendicular to the bolt

Lesson learned the hard way: wear heavy leather/padded gloves for this procedure. When the threads break loose they shot a vibration up my arm that wasn't pleasant.
 
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ukoffroad

Well-known member
Jan 13, 2010
2,125
168
Lynchburg, Va
breaker bar extension is critical, I use a hilift handle as well. Keep meaning to buy a bit of pipe that is smaller for the job.
 

sdtim

Active member
Feb 21, 2021
31
11
Oceanside, CA
+1 on the 'motivator' bar. A cheap 3' or 4' piece of pipe slipped over your breaker bar or wrench is a miracle. Do be careful that you don't pry on it off-angle and strip the head.
 

mlnnc

Well-known member
Mar 23, 2008
266
31
Charlotte
I've worked on two headgasket jobs, both now over 10 years ago. First was a friend's truck, and then mine 6 months later. We used the same 3 or 4 foot pipe each time. Impact socket, breaker bar, and cheater pipe. One person pressing down to hold the socket on the bolt head, and the other person applying the torque. And yes, it's memorable when the head bolt finally breaks loose.

And, if you're removing the heads with the engine installed in the truck, do yourself a favor and get an impact-grade swivel socket for those rear head bolts closest to the firewall.