The 25Lb of Torque rating to install the header bolts, is way to low. I cannot stop my truck headers from leaking. I have put on new gaskets, and then the leak does not happen for about 2000miles, then they start leaking.

I have retightened as needed but still get leaking. I finally said screw it and put 35lbs of torque on the bolts, and this pretty much got rid of the leaks, but was scared to torque any more on them. I have put headers on several of my previous vehicles, and have put at most about 40lbs of torque, and then never had a problem, but these were iron heads, and the grade 8 bolts I bought, would not cause any problems.

On my 2001 Tundra that I had, the heads came with studs, and I used the factory studs over the bolts in the kit, and torqued them to 40lbs of pressure, and never had them leak or loosen up on me within 20,000 miles. Those were aluminum heads. I took off the headers, and they are nice and flat, and fit flush, but alas the leaking. It is only when really getting on it, but it is obvious from the cab that there is a leak. When I had my truck Edit tuned, the computer showed some leaking by the 02 stats. I know that with headers, you will be prone to hearing a lot more valvetrain noise, and I thought that this was the noise. The valvetrain noise does not bother me, but they keep leaking

Does anyone have a recommended gasket that I should use or something? I want to use studs, since this way the pressure is not on the head threads when torqueing, due to these being aluminum. I have ordered ARP 12 point stainless stud kit, and should have that by monday, but still I think the problem more than anything else is the gaskets maybe. I originally used the factory gaskets, then switched to Felpro total seal gaskets, but both started leaking at around 2000 miles, and when checking the torque, they did not loosen up beyond the original retightening after going through a heat cycle.

I know that you should never torque too much on aluminum heads, this is why I got the stud kit. The bolts on these heads are much bigger, and go much deaper than the little studs on the toyota, and I should be able to tighten them a good bit. Usually when torqueing bolts, the thing that rips the threads up is the cross threading when the bolts are stretching. This way with little pressure on the threads in the head, I know that from testing you can go about 40% more torque without problems. Or do you guys think I am crazy to tighten them this much. 40+ lbs of torque.

Any further suggestions would be appreciated!

 

Did you have leaking problems with the stock gaskets? They're real nice gaskets and shouldn't leak.

I'm not sure what brand gasket it was that came with the Supermaxx headers I have but, they are nice also and with only 18 lb-ft of torque on the bolts I've had no leaking problems. You could probably call Mitch at FLP and get a set from him.

When you put those stainless studs in throw a little bit of anti sieze on them so they don't mess up the aluminum threads.

40lb-ft is alot of torque for those bolts and shouldn't be necessary. Maybe that flange is not as straight as you think. If the problem persists you could take the headers to a machine shop and see if they could true up the flange.

I hope you get it figured out because I know how bad a leaking exhaust sucks.

Good luck.

 

I use Byson gaskets (come with Thorley headers) and dont have any problems. I had alot of problems when usng other cheap gaskets. I tried everything from copper gaskets to graphite etc. Byson's worked flawlessly.

 

have you tried the gray sealent with the gasket that they recomend i did that and after 25k on it they still dont leak knock on wood lol

 

I will try byson gaskets, and I don't for the life of me know why I did not think of using that superhightemp gasket sealent. They say it is used specifically for headers!

Thanks, sometimes you just can't think straight when you get upset! I am sure with these two things and my stud kit, that should conquer it!

 

yea that stuff is great

 

Ive had my best luck with using new gm stainless factory manifold gaskets, second runner up has been the metalic gaskets found at napa.