another problem with acert.

What is wrong with the head? Are the bolts just broke off or did it damage the area of the head where the rocker arms sit? Need more info on that.

A new head with a bad core is going to set you back a good bit. I would imagine somewhere in the 3.5-4k range.

 

I have drilled those bolts out before. Get a couple brand new good quality left hand drill bits and take your time and make sure no shavings get into head. Use all new bolts when reinstalling everything. Make sure to torque to proper settings as well.

Can't say anything about the valve stems though.

 

Cat had problems with those bolts and think they even sent out a service bulletin regarding to them. Might be wrong but someone might know for sure.

 

there is an updated bolt. it will look like the shaft has been ground down under the head of bolt.

 

I've dealt with a few of them, all of the broken ones were very easy to get out (as far as broken bolts go), they usually spin right out with a left handed drill bit. Make sure all are changed to the new style. After the 2nd failure, we upgraded all our trucks and haven't had any problems since. Look close at the head where the rocker shaft sits. That area can be worn down if the bolts are loose.

Do you still have the original injector harness's. They are prone to failure to begin with and if they're old, they tend to fail soon after being moved around doing a job like this. I'd hate for you to have a harness failure in a month or two when they could do it now for a few more hours labor. They seem to fail around 500,000 miles, but I've seen them fail at 350,000 and last as long as 750,000.