Headers leaking at the manifold - what would you do

[Vin Man]

Part of my rebuild was the Classic Inline headers. Mike supplied the headers, the gasket, and the stud kit which I installed and torqued according to specifications.

However, after only about 100 miles on my build, I've got a nasty leak coming from the header gasket area.

It has been suggesed that I have potentially one of the following issues:
1. A non-true header. I don't believe this is the case as Mike sells high quality parts. I did not inspect the header for trueness before I put it on, I assumed that it was flat.
2. A non-true head. This is not the case as I had it checked by machine shop that did the head work.
3. Improper torque procedure. Possible
4. Bad gasket - possible
5. Other

Nonetheless, I have to remove the header, check the gasket and replace. Problem is access. To get to header, the intake has to come off. Alternator may need to come out as well. Then disconnect the exhaust pipes from header, unbolt header and check.

I plan to use the Ultra Copper RTV on both sides of the header gasket when I do the repair.

What I would like your opinioin on is the following - would you do this yourself, or would you have the exhaust shop do it? They quoted me <$150 to do the work.

Benefits are they stand behind their work. If it leaks again, its their problem.

Drawbacks:
$150 versus about $20 in parts and my time. I'm guessing 3-4 hours.

I'd appreciate your vote along with any comments or suggestions you may have.

 

[64falconsix]

i would guess gasket or torque. did you re torque after a few heat cycles.the new gaskets useally compress and shrink a little during the first couple of cycles.

 

[mach1 mark]

I purchased headers from Mike and put them on myself, I used the RTV sealer and they don't leak (knock on wood), So I would do it myself.

 

[RagHead]

i would guess gasket or torque. did you re torque after a few heat cycles.the new gaskets useally compress and shrink a little during the first couple of cycles.

I agree with quickersix64, after you install the new gasket re torque the header bolts after a couple of heat up cool down cycles.

 

[Mustang_Geezer]

Install it yourself and use the ultra copper. I've had my header off 8-10 times and by using Mikes new style gasket and the ultra copper I've never had a leak.

The trick is to put a nice bead on both sides of the gasket and let it dry 20-25 minutes then install it.

Tighten everything up, start it and let it run 15 minutes. Let it cool off, retorque all the bolts and drive it. After a week I'll retighten all the bolts again and I have never had a header leak by doing it this way.

Later,

 

[MPGmustang]

Vinny,

I would do it my self as the shop might run into problems with the a/c bracket (when you saw mine) and take that off also, messing up with your belt tightness and other complications that they might not warant as part of the exhaust leak.

just my $0.02

Richard

 

[Anonymous]

Mine was a composite fiber gasket that wouldn't stay torqued then it burned out. I replaced it with a FelPro gasket. I've had no problems since.
Ken

 

[Vin Man]

Thanks for all the input.

Yesterday, I removed the headers. In order to get to them, the following had to be removed:

Carb, intake, alternator, starter, battery.

The gasket was burned out at the dual middle port (twins?) at the top of the gasket.

I'm going to get a new gasket from Mike, but also considering the remflex recommendation. There is a dealer for Remflex here in the valley, so I'll call them tomorrow and get some more info.

Thanks again.

 

[Stubby]

After putting some heat in it, retighten all of the bolts. Check them often. You will probably have two or three that will need to be retightened. When you check them two or three times and they are all tight, you are done.

The ultra copper RTV is the way to go. Put a thin coat on both sides and it will stay. However, if you are useing an O2 sensor, you should use the RTV sparingly, and let it cure well before installing the sensor. It still might cause the sensor to read wrong after awhile. From what I understand, the RTV will leave deposits on the O2 sensor.

 

[Falcon Ranch]

One potential problem that no one had mentioned is warpage...during the many heat and cooling cycles over the years, the manifold will tend to warp just enough that even after torquing the bolt down you still will not have the same values across the manifold...when I had my 351 exhaust resurfaced it only cost $20 bucks...next time you remove the manifold, check the gasket surface with a straight edge.

 

[Vin Man]

OK, I plan to reinstall headers tonight or tomorrow.

Just to make sure I get this right, what procedure do I use to properly fasten the headers to the manifold. My plan was

1. apply the ultra copper rtv to both sides of the header gasket
2. Align the gasket against the manifold
3. Slide the header into place
4. Finger tighten the bolts onto the studs
5. starting in the top middle of the header, go two turns on the bolt
6. drop to the middle lower stud, then 2 turns on the bolt
7. move from the middle out in both directions until all have had two turns on the bolt.
8. Starting at middle top again, repeat process. Repeat until torque limit of 24 ft-lbs is reached.

Did I get it right?

 

[Stubby]

I don't know about the two turns, but you should just snug them and progressively work them all down evenly.

Also make sure you have everything ready and do it quick enouggh to get it done before the silicone sets. This doesn't happen fast, but forgotten things have a way of taking longer than expected.

 

[Falcon Ranch]

After the first hundred miles, be sure to re-torque the bolts...after that, once a month is a good time to check the bolts regularly...if they are still good, then you can change it to every three-four months...as the manifold heats up it will expand and if any bolts are not proper it will loosen them...after a while after the gasket gets set from the periodic checking eventually you will be worry free...good luck.

 

[CobraSix]

You shouldn't have retorqueing issues with the studs like bolts.

I didn't see this one in time, but it is possible to remove the headers without removing the intake manifold. It's a royal PITA but possible. I did mine just by removing the alternator, and unbolting the exhaust system from the car.

I only did it that way because I didn't have any replacement intake gaskets.

 

[Vin Man]

You shouldn't have retorqueing issues with the studs like bolts.

I didn't see this one in time, but it is possible to remove the headers without removing the intake manifold. It's a royal PITA but possible. I did mine just by removing the alternator, and unbolting the exhaust system from the car.

I only did it that way because I didn't have any replacement intake gaskets.

I live just a few miles from Mike at ClassicInlines so I picked up my new gaskets yesterday. You must have got under the car to get to some of those bolts if you did it without removing the intake!

 

[jahearne]

If you keep blowing gaskets, it's because the surface is not true. Take a straight edge to the manifold side of your cylinder head to check for gaps. If gaps are big enough you might have to take your head to a machine shop to clean up the surface where the header bolts onto.

Sometimes I take a flat sharping stone to the surface soaked with WD-40 to clean it up enough for a good seal.

 

[Stubby]

Sometimes you need to retorque, sometimes you don't.
If you don't, and you should have?
It never hurts to check. It might have saved you this headache.

 

[CobraSix]

Stubby,

I agree...I checked a month later.

I actually didn't get under the car. Biggest problem I had is that some of the studs came out with the bolt, some didn't. It took a lot of muscling to get it off the studs. On the convenient side when I was putting the headers back on, I just had to get them over the studs and they popped back into place. I was only able to pull the headers out enough to rest on the studs that didn't move. When placing the gaskets, I just pried it a part a little bit more and put the gasket in.

It was a royal PITA and if I had to do over again, I'd have ordered some intake gaskets and done it. But it was one of those "I've had enough of this" kind of days so I just decided to fix it that day (I had the exhaust gaskets already). I had to pull them because the port divider had broken lose in the head and I was tired of the rattling so I pulled it out.

 

[Vin Man]

I just finished bolting the headers back on.

I got a new header gasket from ClassicInlines, and a tube of the RTV Ultra Copper permatex. I trimmed out the middle port of the header gasket per Mike since I don't have a port divider.

I followed the technical data sheet on the use of the RTV - I applied to both the header and the head.

I then put on the gasket, and the headers.

Starting in the middle and working out, I snugged down all the bolts by hand.

Then, I torqued each bolt to 24 ft-lbs per the ClassicInlines spec. Again, started in the middle and worked my way out.

Went over each bolt about 5 times to ensure they were torqued properly and would no longer tighten past the torque limit.

I will now let the RTV cure for a minimum of 24 hours. I may start putting back the intake and other compenents in hope of starting the car tomorrow, but no rush. Last thing I want is more header leaks.

 

[Williboy]

Your lucky you get to remove your intake!!!!!!