I have a 400 cummins and it is leaking a little water from between the heads and bloc

[rioncrsn]

I have a 400 cummins and it is leaking water between the heads and block. just wondering how serious this is and how to fix it.

 

[JBGASH]

I have one that started doing that 7 yrs ago, get the motor warmed up and put 4-6 cans of Conklin Dike in the radiator. I was surprised on good it worked, we are still using the truck with no leakage.

 

[rioncrsn]

all i need to do is get the engine hot and poor it in.

 

[JBGASH]

yes, then take her for drive to insure it mixes well.

 

[Randy88]

Sounds serious to me, maybe a head gasket or the bolts are loose if its weeping out by the gasket, I'd pull the head off and have it checked out to see if its warped and or cracked and if the gasket's bad, is it leaking water into the engine as well, do you get water in the oil or just leaking on the ground?

 

[miro]

Randy 88 is right. leaking head gaskets was a problem on them. Bolts would stretch and or brake. you don't need an overhaul probably just head gaskets and new head bolts and you'll be good for years.

 

[John C.]

As I recall there used to be different O ring seals for the head gaskets. I was told there are oversize rings for the gasket to adjust for that issue.

Big bore Cummins used to be well known for that issue. I suppose they fixed it by now. Perhaps there will be some more input here.

 

[2stickbill]

I have seen high mileage Cummins leaking oil and water.The heads would vibrate causing the liners to wear are crack the ridge.Have seen where the block had to be resurfaced too.But these engines will run a long time doing this.Easier to do during out of frame over haul.

 

[busdrivernine]

jsut depends on what the block surface looks like Cummins offewr oversized headgaskets but u really need to pull it down and check block surface no sence in spending good money for a temp fix ( band aid on a cut that needs sewien up) done been that route $2000.00 for head gasket with no garanty or 12 500 for Cummins Recon engine with 2 yr warranty ended up total out the door price of $21,000 for the repair but got a good motor that now has about 200,000 on and only repair so far is STC valve and water pump

 

[sinnful]

I know the big cam 4s were notorious for cracked heads and leaking head gaskets. We went through them often on a couple older farm trucks.