Well, been looking over the truck the last week. Originally had, what I thought to be, a bad water pump. Looked to be leaking out weep hole due to coolant seeping along the timing cover below it. Replaced the pump and all was well for a couple days. After a 4hr trip I found a small coolant puddle. Started tracing it and found the source at front-middle of the head. Leaks down behind the fan housing and follows the timing cover under the water pump. 

Warmed up the truck and when I squeeze the upper radiator hose small bubbles emerge from the head in the area pictured. 

Will start tackling the head in the next couple weeks. Surprised it blew with arp studs in place at 135lbs...

Is this a common area for it to go and is there a water jacket behind there? Could the new pump have had anything to do with it? 

My first time ever having to do a head so I'm sure I'll have plenty questions along the way. 

Personally I've never used any sealant product for coolant system in the Cummins. I done it once in my 1996 Dodge and it made quite the mess out of the cooling system. I got it flushed out and replaced the intake manifold gasket the was bleeding out over the front of the engine. Changing the gasket did way better than adding the stop leak which only bought time and eventually start to weep again later on. 

 

NOTE: Old mechanic trick back in the day for junkers was to mix a can of condensed milk and pepper together. Not something I would even suggest but in a pinch it would work just like any stop leak product. Just more fun to flush that stuff out later.  

52 minutes ago, Mopar1973Man said:

Personally I've never used any sealant product for coolant system in the Cummins. I done it once in my 1996 Dodge and it made quite the mess out of the cooling system. I got it flushed out and replaced the intake manifold gasket the was bleeding out over the front of the engine. Changing the gasket did way better than adding the stop leak which only bought time and eventually start to weep again later on. 

 

NOTE: Old mechanic trick back in the day for junkers was to mix a can of condensed milk and pepper together. Not something I would even suggest but in a pinch it would work just like any stop leak product. Just more fun to flush that stuff out later.  

I think you miss the point of stop leak it is what it is. IE buy some time before the job is done then flush the system. Peeps might not be able to afford the job or not be without the vehicle for a while. I carry several tubs as a concrete plant with 200 cube on for the day ain't going to want to stop and cancel cos of a coolant leak 

I once bought an S10 pickup at auction (video auction) from Oklahoma. By the time it was delivered to Kansas City, early winter had set in. That engine didn't have anti freeze for some dumb reason. Used a can of K&W block seal and put probably 80k miles on it before a pizza delivery driver blew a red light and totaled the truck.  I got lucky on the repair, but I was told specifically to use K&W.

Any updates on this?

 

On 5/20/2021 at 8:23 AM, Mopar1973Man said:

Any updates on this?

 

Have drove the truck for ~800 miles so far and it still hasn't leaked yet. Just keeping a close eye on it and haven't had to use any stop leak yet. Will see, not sure how it would just stop like that. Coolant levels are staying fine