If you own a Cat, read this.

It's no secret that the head gasket water jackets are a weak spot on the later model C15 engines. They don't line up or seal proper no matter what you do, anyone who's torn Cats apart can probably tell you they've seen signs of rust on the bolts from this exact thing. They are very susceptible to heat... I know a few mechanics who use a aviation sealant on the spacer to combat this.

I stumbled upon a update but had to climb mountains to verify. I called Cat, Peterbilt, Kenworth and Western Star and they all told me the latest update for my water jackets were part # 3E6772 which is this.....



Now there is a update but it isn't being called a update but instead a "optional service replacement". After Cat told me thats my best option, I gave them the new part #. They verified it was a update to mine but they aren't calling it a update and it does not show up on Thier news bulletins, it's description says better material and design for better sealing. I assume it will show up once old stock gets sold..... of course you should verify this yourself.

The new part # 3591439 and looks like this.....





These new ones are very hard and feel like a neoprene/urethane.

I just thought I would post this for anyone doing a rebuild or new head gasket so you don't get burned like me. I just rebuilt my entire engine only to find this out a week later...... we're tearing the head off right now and updating them.

 

Well lol There's a side reason for that. I got my air intake temp too hot and it took out the water jackets. That being said, I would have done it anyways. I replaced every sensor, wire, seal and everything else. I spent a lot of time and money to make this thing brand new, not just inframed. I'd tear it down because I'm stubborn like that and want this thing to last a long time.

 

Not ambient air temp, intake air temp. Ext temp, head got hot and I'm lucky it didn't Crack.