My 955K has a d330c and it keeps blowing the head gasket at number 1 cylinder. The block has been planed and the head is new, does anyone have any ideas?
I would have to assume the liners were replaced and the liner projection was set to the correct height? Are you using genuine Cat head gasket and using a properly calibrated torque wrench? Also how many times has this happened and how many hours between each failure?
I'll second and agree with Kshansen, check the liner projection and then double check it!
I also agree about checking liner protrusion. They have to be clamped down while checking, if not, you may not get an accurate reading. Each one should be checked in 4 places to make sure the liner flange is concentric with the counterbore. They should all be similar if the block machining was done properly. With new liners and remachined counterbores they should be about .004 . I am assuming you are referring to a compression leak. The service manual should have a minimun spec, probably about .001" and also a maximum, probably about .005" or .006".
The liners were checked in multiple places during the rebuild. It looks to me like the pressure is coming from the water port. The last gasket was an aftermarket but the one I have now is genuine Cat. do you think that could be the problem?
Second time it has happen with about 100 hrs. each time. Just had the wrench re calibrated before the last one. Certificate says +/- 3lbs.
When the block was decked, were the liner upper counterbores recut? It almost sounds like the liners are too high. You said that the liner protrusion was checked, but what were the actual numbers? I have used both cat and aftermarket head gaskets with no problems on newly machined blocks. Are the machining marks quite severe or is the deck surface reasonably smooth? If the machining marks are too severe, the gasket may not seal properly around the coolant passages.
The head may warped slightly or not shaved enough , I would run it back again and the block , and make sure it is shim ed right no the value side , just a guess on your thread , good luck .
I'm sure you probably did but are you re-torquing the head after the spec'ed run in time.
Yes doing everything by the book and still can't figure this one out.
Did the pistons get a cut down if the block was shaved they would usually need this detail, the usual cause of this gasket failing on 1 cylinder would be cylinder liner hight or damage to the counter bore face. tctractors
Never thought of that. Is there a spec. somewhere on piston height or would you just make note of how much the block was shaved and take that much off the top of piston? I know it is common on, say motorcycle engines when doing modifications for performance to vary the gasket thickness under cylinder or the head gasket to adjust what some refer to as "squish height". I can see with an older engine that you may not know the full history on that the block could have be shaved more than once and now it is getting to a critical point.
On the top surface of the cylinder block there is a V mark stamped on the one side of every cylinder, the V being for piston location on assembly, when the V is missing this indicates the block has been trimmed and the pistons will need facing off to establish the hight standard, what has been machined off the block will also need to be removed off the pistons including any valve pockets, CAT always seem to use thick valves that stick well out of a cylinder head. tctractors.
I'm not clear on your "blown head gasket". Is it leaking compression (bubbles in radiator neck?) or water at head to block joint or oil at the same joint. If the block has been decked where the dowel inserts and projections checked? along with piston to head clearance. Also what did you use or did you use a head gasket cement?