Exhaust re-do

Engine troubles? Try here.
User avatar
McCall Pinz
Switzerland
Posts: 566
Joined: Sun Mar 11, 2007 6:01 pm
Location: McCall, Idaho

Exhaust re-do

Post by McCall Pinz » Fri Mar 14, 2014 6:57 pm

There isn't much information in any of my manuals regarding the exhaust system and a small write-up might help speed things up for others. The system is pretty simple, but can be very frustrating as you're laying on your back and dirt is falling in your face. Loosening exhaust nuts or even studs seem to be common on our trucks. My Pinz had a bad exhaust leak right at the cylinder head gasket, a few pin-holes in the shell of the heat-exchanger, and a rusty-but-solid muffler. The whole length was removed, patched, or replaced, and ceramic coated. Here's the step by step I recommend. This isn't the order the I used, but in retrospect it seems to be better.
02.jpg
you can see black around the leak at #4 cylinder
02.jpg (227.03 KiB) Viewed 5060 times
1. Soak every nut and bolt in pb blaster or liquid wrench or something similar and go away for a day, the do it again and go away again.
01.jpg
01.jpg (210.64 KiB) Viewed 5060 times
2. Lay out every 12 and 13mm socket or wrench that you own and make sure you have a couple extensions and flexible "u-joints" for your sockets. 1/4" and 3/8" drive and deep and regular sockets. You'll need them all if you take off the header. Note too that for most projects I advise to have a beer handy- not this one- its so frustrating I saved the beers until the end.
05.jpg
05.jpg (207.57 KiB) Viewed 5060 times
3. Support the HE and muffler with a floor jack and unbolt the 6 bolt flange connection between the header and front of the HE, Remove the hanger bolt on top of the HE, then remove the 2 bolts at the rear of the muffler and lower the whole system in 1 piece. Some of the nuts at the front of the muffler, under the heat shield, are especially difficult to get at from underneath and its much easier to work on when the whole thing is out.
06.jpg
06.jpg (245.71 KiB) Viewed 5060 times
4. Now comes the joy of pulling the header. You get to use every possible combination of sockets and extensions and joints and adapters. Cylinders 3 and 4 are reasonably accessible, but 1 and 2 each have a very difficult to reach nut. Some nuts were loose and others only came out with the stud. Release the parking brake to loosen tension on the cable if its in your way.
5. Save the nuts and bolts and soak them in PB blaster. Keep track of the 8 header nuts and washers they're nice little pieces of engineering. 11 of the 12 flange nuts are special slotted locking nuts and don't need lock washers. Clean them to see the slots. Replacements are available on ebay- same as BMW's use. 1 of the nuts by the HE is different- thinner than the rest and also has a shorter bolt too.
09.jpg
white deposit from lean condition due to exhaust leak on #4
09.jpg (329.27 KiB) Viewed 5060 times
6. With everything out for repairs, now is good time to make sure your 4wd locker switch is grounding correctly. Also a good time to replace the hoses with SCAT hose from Aircraft Spruce.
7. Make any repairs. After sandblasting and patching a hole in the HE, the whole thing, including the SS muffler was ceramic coated. Its supposed to help with keeping the exhaust gasses hot.
8. Inspect and replace gaskets. Install the header centering rings on the heads and fit the header back on. The torque values are __
9. Bolt the HE and muffler together again. Use anti-seize on all the nuts and bolts in case you ever have to do this again.
10. Lift the assembly back in place with a jack and hand tighten the 2 rear muffler nuts and bolts. Slip the HE hanger bolt back in place to support the assembly.
11. Reconnect all the air hoses
12. Align the HE/muffler with the 6 bolt flange on the flex coupling of the header. Slip in a new gasket and bolt up tight. Remember the one thinner nut and shorter bolt here.
13. Check the bolts for torque from stem to stern- don't forget the top hanger bolt! Enjoy beer now.
eat, sleep, Pinzgauer

User avatar
McCall Pinz
Switzerland
Posts: 566
Joined: Sun Mar 11, 2007 6:01 pm
Location: McCall, Idaho

Re: Exhaust re-do

Post by McCall Pinz » Fri Mar 14, 2014 7:10 pm

Need to add the rest of the pictures
12.jpg
tight fit
12.jpg (195.82 KiB) Viewed 5058 times
14.jpg
14.jpg (182.13 KiB) Viewed 5058 times
16.jpg
See the slots on the nuts
16.jpg (190.95 KiB) Viewed 5058 times
18.jpg
18.jpg (209.37 KiB) Viewed 5058 times
21.jpg
the center nut is thinner and the bolt shorter
21.jpg (198.38 KiB) Viewed 5058 times
eat, sleep, Pinzgauer

User avatar
TechMOGogy
Canada
Posts: 2830
Joined: Wed Feb 01, 2012 11:39 am
Location: Ontario, Canada

Re: Exhaust re-do

Post by TechMOGogy » Fri Mar 14, 2014 8:44 pm

Great post!
Should be in the Tech Sessions - perhaps Vince can move it and adjust text so it is with pics?!
Cheers,
72 Pathfinder | 75 710M 2.7i | 96 350GDT Worker

User avatar
Haf-e
United States of America
Posts: 822
Joined: Thu Oct 06, 2011 5:25 pm
Location: Mount Vernon WA USA

Re: Exhaust re-do

Post by Haf-e » Sun Mar 16, 2014 11:23 am

Very nice write-up - thanks!

Who did your ceramic coating? I want to do the same thing some time.

So did you leave the front connection of the flex couplers to the headers just clamp on? no exhaust leak there?

Did you also have the flex coupler ceramic coated?

The slotted bolts are interesting - haven't see those before. You did use these on the connections to the cylinder heads did you?
Haf-e

1971 Pinzgauer 710M

Image
Disc Brake Conversion Kits for 710 and 712 Pinzgauers
www.klugewerks.com

User avatar
westernair
Posts: 747
Joined: Sat Jan 01, 2011 11:14 pm
Location: Tacoma, WA

Re: Exhaust re-do

Post by westernair » Sun Mar 16, 2014 12:25 pm

Haf-e wrote:Very nice write-up - thanks!

Who did your ceramic coating? I want to do the same thing some time.

So did you leave the front connection of the flex couplers to the headers just clamp on? no exhaust leak there?

Did you also have the flex coupler ceramic coated?

The slotted bolts are interesting - haven't see those before. You did use these on the connections to the cylinder heads did you?
Chris,

Can you just galvanize the parts? Your source you used for all your other parts id a great job.
Mot sure what heat does to that material though.
Shawn

62 haffy Bantam
61 haffy 4 door

72 710K - Sold
73 712M - Sold

User avatar
pcolette
United States of America
Posts: 1518
Joined: Sun Dec 10, 2006 7:38 pm
Location: Southwest Wisconsin

Re: Exhaust re-do

Post by pcolette » Sun Mar 16, 2014 12:38 pm

Nice job and write-up!

I've never seen those slotted nuts before. The ones I've done have all been just regular (very rusted) hex nuts. I replaced them with SS bolts, washers and nuts. Do you have a part number for the slotted nuts?
The last heat exchanger I removed had some of the nuts welded to the flange and the HE shell covered them up. From the few I've seen it might be that they had more than one supplier of the heat exchanger.

Thanks for the tips and photos.
Paul C.
_________
'73 Swiss 710M
'89 Puch 230GE
2002 MB G500

User avatar
Haf-e
United States of America
Posts: 822
Joined: Thu Oct 06, 2011 5:25 pm
Location: Mount Vernon WA USA

Re: Exhaust re-do

Post by Haf-e » Sun Mar 16, 2014 2:57 pm

Don't think you can just galvanize exhaust parts - also it would be hard to do the heat exchanger as they would want it taken apart (they can't end up with pockets catching the liquid acid and zinc solutions (warning - they will drill holes in parts to allow the zinc to drain out before dipping - so talk with them PRIOR about that issue).

I've used the ceramic coating on a cast iron header and was very impressed with the results... Hadn't thought about doing the heat exchanger actually - if they did it on the inside it would reduce the heat output of it (at least based on what they claim is the results of the coating.

Hummmmm....

User avatar
McCall Pinz
Switzerland
Posts: 566
Joined: Sun Mar 11, 2007 6:01 pm
Location: McCall, Idaho

Re: Exhaust re-do

Post by McCall Pinz » Mon Mar 17, 2014 11:33 am

Primo's powder coating in Meridian Idaho did the ceramic coating and only did the exteriors. Great guys. If the interior of the HE was ceramic coated, it would reduce the heat transfer. The flex connector is one that EI used to install and it was powdercoated too. There's never been a problem with it.
I agree that the HEs have a lot of variations- mine only had 1 unique nut/bolt combination, but that seems to be because of the low quality control on the HE tin. Others might be different. The original nuts were very "rusted", but I realized they were slotted copper after taking a wire brush to them. New slotted nuts are available on ebay if you look for "copper locking exhaust nuts M8." Mine came from seller sflraver. I didn't use these at the heads since the originals were already copper or silicon bronze and have a very unique shape and matching washer that's probably designed for a reason.

The whole job really made a difference to the truck. The SS muffler has a smoother, mellower sound than the original and taking care of the exhaust leak seems to have restored my idle. Not sure if that could have been the problem, but the truck now idles perfectly at stop lights where it would falter last fall.

I'll try to edit this whole thing and move to the tech sessions. thanks
Last edited by McCall Pinz on Mon Mar 17, 2014 2:41 pm, edited 1 time in total.
eat, sleep, Pinzgauer

User avatar
edzz
United States of America
Posts: 1309
Joined: Tue Aug 11, 2009 12:13 am
Location: Coeur d'Alene, ID

Re: Exhaust re-do

Post by edzz » Mon Mar 17, 2014 12:06 pm

Nice job and good write up.

This looks all to clean now, time to find a mud puddle. :P
Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.

User avatar
Haf-e
United States of America
Posts: 822
Joined: Thu Oct 06, 2011 5:25 pm
Location: Mount Vernon WA USA

Re: Exhaust re-do

Post by Haf-e » Wed Mar 19, 2014 12:11 pm

Look great - i didn't realize that powder coating guys could do a ceramic coating on exhaust parts - the one I did was done by "Jet Hot" in Pheonix and came out great.

So did you have anything done with the interior of the heat exchanger?

Did they coat the inside of the headers as well as the outside?

Did you just leave the flex couplers attached to the headers when they were coated?

Thanks for the info!
Haf-e

1971 Pinzgauer 710M

Image
Disc Brake Conversion Kits for 710 and 712 Pinzgauers
www.klugewerks.com

User avatar
HawaiianGauer
Posts: 52
Joined: Thu Jan 31, 2013 12:17 am
Location: Prescott, AZ

Re: Exhaust re-do

Post by HawaiianGauer » Wed Mar 19, 2014 1:48 pm

Outstanding write up, pictures, etc. It's people like you that take the time to do this that makes 'Gauer ownership by people like me possible. Thank You!! :D

X
Mahalo for your assistance!

Harry X.
73 'Gauer 712M

check out the X-Gauer in action: https://www.youtube.com/watch?v=cYj_UNQDgpM

User avatar
McCall Pinz
Switzerland
Posts: 566
Joined: Sun Mar 11, 2007 6:01 pm
Location: McCall, Idaho

Re: Exhaust re-do

Post by McCall Pinz » Wed Mar 19, 2014 3:11 pm

I only cleaned the inside of the HE with compressed air to get rid of any loose bits or dirt. Same with the header. The flex couplers were so tight to the header that they probably don't even need the clamps. Yes, that stayed in one piece when they coated it.

Definitely time to find a puddle now!
eat, sleep, Pinzgauer

newtopinz
United States of America
Posts: 62
Joined: Tue Dec 31, 2019 5:59 pm
Location: Monterey Bay area, CA

Re: Exhaust re-do

Post by newtopinz » Sun Mar 01, 2020 9:32 pm

Excellent write up and super helpful McCallPInz. Thank you.

I started thinking I was just going to replace the muffler, but ended up replacing the HE along with removing the header for the flex kit upgrade. I removed all of the header studs except one. now I'm struggling to remove the lone stud in place while I have the exhaust parts sandblasted/ceramic coated just like you did.

I do have a few questions
1. I am planning to replace all header studs with new ones I bought from SAV. Not sure if they are stainless steel, but if not I think anti seize would be adequate? Or should I hunt down stainless steel studs as someone mentioned they found in a local hardware store.
2. Should I put locktite in the thread portion that goes into the head? Or anti seize? Or anything at all?
3. Anyone knows the torque spec for the stud? I am thinking using two bolt method to install it, any different/better idea to install the header studs?
4. I am thinking of installing the headers, then putting the flex kit on the header, then bolting up the HE/muffler together last. Should I install the flex kit in its most compressed or most extended position or somewhere in between? I am thinking to allow expansion one would want to clamp it in it's most extended position when cold.
5. Any torque spec for the header nut, I see you left it blank. I was thinking of just using the german torque spec: good en tite.
6. best way to remove a stuck stud? I tried PB blaster and vice grip, which was a newbie mistake. I will try to rethread using a die set and then use the two bolt method. If not I will try to chuck stud removal tool +/- heat on the head.

Thanks
Kelvin

murrayjp
United States of America
Posts: 55
Joined: Thu Jul 19, 2018 6:29 pm

Re: Exhaust re-do

Post by murrayjp » Mon Mar 02, 2020 2:44 am

Nice write up and the Pic are great
thanks
Bill

User avatar
rmel
United States of America
Posts: 1192
Joined: Sun Sep 25, 2011 12:19 pm
Location: Woodside, CA
Contact:

Re: Exhaust re-do

Post by rmel » Mon Mar 02, 2020 9:34 am

You could try to remove the last stud with a double locked nut in place.
Squirt some penetrating oil in there but do not over force it. If it fails
to move leave it in place -- as long as the exposed threads are good don't
worry about it. They are set in am aluminum head in a blind hole so don't
push your luck. I've taken Pinz heads for valve jobs with stubborn studs
in place -- not a big problem.

The exhaust nuts are brass, with a ball seat and a special washer to receive
the ball to the flat flange of the header. Make sure you have the right hardware
and not some DIY substitutes.

Since this is a M8 Brass on steel 8.8 stud the highest torque should not exceed
the max limit for a Brass nut -- staying below 110 in-lbs (12.4 Nm).

The proper procedure is to first seat the studs in the heads -- just finger tighten only.
Get the sealing rings and gaskets on the top of the exhaust header, put header in
position add the special washer and nuts, jiggle it as you loosely tighten BEFORE final
tighten. I never use a torque wrench on these nuts, I just tighten slow nut after nut,
repeating to a uniform amount of low'ish force until it "feels" right. You will be hard
pressed to actually get a torque wrench in there anyway. These Brass nuts will not
come loose, they will take a set at a low torque, you just want enough force there to
compress the gasket. If there is a exhaust leak be careful not to over tighten, make
sure it's not a seating issue.

Then install the Flex coupling. You should be able to do that W/O separating the HE
and Muffler, unless they are already apart then it would be easier to reassemble from
front to back.

P.S. If you did not get your exhaust gaskets from EI then get a couple of sets from
them -- trust me on that tip.
Puller: 71' 710K 2.7L EFI aka Mozo
Follower: Sankey MK 3, 3/4 Tonne
Rescue Pinz: 73' 712M

Driver: Ron // KO0Q

Post Reply