Posted By: saukvillage
Coolant leak from header bolts - 06/18/09 12:49 PM
Started new 440ci motor for the first time and after after running to about 200 degree I cut the motor off. Started checking for leaks and I notice coolant coming out the header bolt near the fire wall. So, what can be done to fix this problem,
Thanks.
Posted By: moparpollack
Re: Coolant leak from header bolts - 06/18/09 12:57 PM
Did you use stainless steel bolts? Pull the studs and put sealant on them. I they aren't stainless they will rust shut.
Posted By: therocks
Re: Coolant leak from header bolts - 06/18/09 02:45 PM
We use antisieze on them and no leaks.I went back to studs even though the aluminum heads are dry.We use studs wher ever they fit in all our heads.Rocky
Posted By: Mofopar
Re: Coolant leak from header bolts - 06/18/09 04:08 PM
Only thing I'd add is to brush the threads clean and spray with brake cleaner before applying the silicone.
Posted By: pleasantk
Re: Coolant leak from header bolts - 06/18/09 05:27 PM
Had the same problem last fall on the back driver side. I have studs on mine and after talking to my builder, he recommended running a can of K&W through the cooling system. No leaks since and no issues with temp. Just make sure to follow instructions EXACTLY as written. Want to make sure coolant and K&W don't mix.
Posted By: hunterstroble
Re: Coolant leak from header bolts - 06/18/09 05:59 PM
I huse loctite teflon pipe sealant, and Have used studs and bolts. Works great. Studs are better but sometimes you don't have the room.
Posted By: Magnum
Re: Coolant leak from header bolts - 06/19/09 03:25 PM
What's happening here is your are trying to seal a straight thread. That was NEVER meant to be done.
Studs with a shoulder between the 2 threads or...
Silicones is your best option here.
Teflon tape, pipe paste, pipe thread sealant are for lubricating and sealing tapered threads.
Posted By: SomeCarGuy
Re: Coolant leak from header bolts - 06/20/09 03:35 AM
Gray high temp RTV, SS bolts
Posted By: RapidRobert
Re: Coolant leak from header bolts - 06/20/09 03:41 AM
as said the shouldered stud is the best & can trim the outer(fine thread) end for clearance, only need enough threads for the nut to be flush
Posted By: Dougsmopars
Re: Coolant leak from header bolts - 06/21/09 02:39 AM
very common problem. Most header bolts break the wall into coolant channel. Wall is very thin in that area. I use a good high temp sealent when ever i install headers.It's nothing to worry about just a pain to do. Make sure you clean the coolant out of hole before you reinstall the bolts with sealent.
Posted By: old340dog
Re: Coolant leak from header bolts - 06/21/09 12:18 PM
Will I experiance this problems with my 340 also?We just dropped motor back in yesterday and got headers bolted up. I haven't put any coolant in yet. I'm using Edlebrock RPM performer heads. So should I take the header bolts out at back of motor and put some sort of thread sealant in? Or do all of the header bolts?