m38a1/m170 exhaust

bl5211a · Post by **bl5211a** » Fri Jul 11, 2014 4:55 pm

Getting ready to assemble exhaust system, do folks recommend using high temp sealant on pipe flange gaskets?

MODIFIED · Post by **MODIFIED** » Fri Jul 11, 2014 5:21 pm

I opted to make my own copper flange gaskets for exhaust joints. After annealing to precipitate ductility, then spray a few coats of ultra copper sealant that acts as an added conformal layer.

I've had little success with other forms of RTV or sealants when mating high temp flanged surfaces along the exhaust system to the stock gaskets.

Initially, a properly prepared mating surface despite what you choose; either dry or with sealant, insures a good long lasting seal upon any connection, meaning that the contact surfaces both join flat and clean.

OKCM38CDN · Post by **OKCM38CDN** » Fri Jul 11, 2014 7:15 pm

On my M-38 CDN which is very similar to the M-38A1 the only thing I did was make sure I used brass nuts on the bolts on the exhaust pipes themselves per the SNL... I have been running my M-38 for almost 10 yrs with out a problem in the exhaust system.

As long as you are using the military triangular fittings and gaskets all should be well...

Hope this helps...

bl5211a · Post by **bl5211a** » Fri Jul 11, 2014 7:27 pm

Did u use brass nuts on muffler to pipe flange and pipe to pipe flange ?

OKCM38CDN · Post by **OKCM38CDN** » Sat Jul 12, 2014 5:54 am

All nuts were brass, on the exhaust manifold to block (Special Castle / Lock nuts) then all the bolts from that point on had the standard gasket (triangular in shape) and 3 bolts / Brass nuts per connection...

Hope this helps...

billybob · Post by **billybob** » Sat Jul 12, 2014 6:12 am

Where did you find the brass lock nuts? Thanks.

bl5211a · Post by **bl5211a** » Sat Jul 12, 2014 7:06 am

I have not been able to find the smaller ones in brass , but did find the 3/8-24.

Does anyone have the 5/16 brass nuts?

Post by **wesk** » Sat Jul 12, 2014 8:49 am

The only time any added sealants are used on exhaust system port gaskets is when the assembler doesn't want to machine irregularities out so they fit together properly. It is a poor or lazy man's band aid.

OKCM38CDN · Post by **OKCM38CDN** » Sat Jul 12, 2014 12:36 pm

The 3/8-24 Lock nuts for the manifold are available from most of the military vehicle suppliers (I just bought some from Mullins)

I found the standard 5/6-18 at ACE hardware... My local store has closed so I will need to see if the new one stocks them...

Hope this helps...

billybob · Post by **billybob** » Sat Jul 12, 2014 1:01 pm

Thanks, My Ace store also closed several years ago. I sure miss it. I read somewhere that they may not have a MVPA jeep reunion in Jeff City this fall. I hope they do.