What type of thread size is this?

linx310 · Post by **linx310** » Mon Jul 19, 2010 8:03 pm

This is my vacuum line that runs from the vacuum tee to my fuel pump on my 1952 M38A1

What size of thread is used on the "screws" at each end of the line?

Is it some kind of special type of thread?

The parts circled in red screw into each other.

idiocrates · Post by **idiocrates** » Mon Jul 19, 2010 8:19 pm

The fitting is called an inverted flare...the top one is the female.....the lower one is the male. Its hard to tell from the photo but the tubing is either 5/16" or 1/4". The upper fitting is usually used where the tubing terminates and is screwed into whatever it is using the 1/8" NPT thread on the part of fitting outside your red circle. If the tubing is 1/4" the thread on the nut will be 7/16" x 24. If the tubing is 5/16" the thread will be 1/2" x 20. Hope that helps.

linx310 · Post by **linx310** » Tue Jul 20, 2010 7:16 am

Any idea where i can find an adapter that goes from 1/2" inverted flare male to 1/8" NPT female?

I tried autozone and lowes already...

idiocrates · Post by **idiocrates** » Tue Jul 20, 2010 7:46 am

Either a NAPA store or an O'Reilly's should have what you're looking for. Around here we have an old Gibson's store that is still loaded with brass fittings. If none of these sources work out for you there are numerous web sites that sell brass fittings.

So are you saying you need an inverted flare nut for 1/2" tubing.....or are you looking for an inverted flare nut for 5/16" tubing? The nuts are sized based on the OD of the tubing.....not the wrench size. And, of course, if you are going to change out the nut you are going to have to rebend and reflare a new piece of tubing cause the nuts are essentially not replaceable unless there is enough excess length built into the tube to accommodate cutting off one of the old nuts and reflaring the tube. Usually, I might add, its the fitting that goes south and not the nut since the nut is generally (although not always) steel while the fitting is much softer brass or bronze.

linx310 · Post by **linx310** » Tue Jul 20, 2010 8:14 am

or are you looking for an inverted flare nut for 5/16" tubing?

It is the one for the 5/16 tubing...I need it to screw into the inverted flare Tee and convert to a NPT female thread so a hose barb can be attached.

idiocrates · Post by **idiocrates** » Tue Jul 20, 2010 8:37 am

A company called Couplings Company, Inc makes this piece called a swivel......might be just what you're looking for....
Their web site is www.brassfittings.com They are located in Lincolnshire, IL For a 1/4" hose by 5/16" inverted flare the part number is 815LCD. For a 5/16" hose by 5/16" inverted flare the part number is 815LDDD.

Post by **wesk** » Tue Jul 20, 2010 9:00 am

If you are referring to the hose connection to the wiper "T" for the wiper supply hose that originally was simply a short pieced of tube flared with an inverted flare fitting on one end for the "T". If you have a tube beading tool you can add a small raised bead on the slide on end to help retain the wiper supply hose better.

Niclas · Post by **Niclas** » Tue Jul 20, 2010 10:43 am

linx310 wrote:Any idea where i can find an adapter that goes from 1/2" inverted flare male to 1/8" NPT female?

I tried autozone and lowes already...

check http://fittingsandadapters.com/

/N

linx310 · Post by **linx310** » Tue Jul 20, 2010 11:25 am

Here is ORD 9 description

MF PART # WO-807846

LINE, vacuum pump to tee, assy. ._
Composed of:
2 NUT
1 TUBE (21 5/16 in.)

So I think its a 5/16 line...its the one that goes from the Tee at the front of motor to the vacuum pump.

idiocrates · Post by **idiocrates** » Tue Jul 20, 2010 11:37 am

Yeah.....just looking at his pic and the general bends of the piece of tubing I suspected I was looking at the piece that goes from the vacuum pump to the "t" located just in front of the pcv valve....and according to my manual this is a piece of 5/16" tubing. I had never noticed that on this side of the vacuum pump the plumbing is 5/16" while on the other side its 1/4". Guess that's to keep ya from mixing up the plumbing. My a1 is devoid of all vacuum system plumbing so I was going strictly by the book. I wonder if this really such a good place for a hose instead of rigid tubing.....but then again maybe Mr. K is correct and I am barking up the wrong tree.....sure wouldn't be the first time.

linx310 · Post by **linx310** » Tue Jul 20, 2010 12:04 pm

I wonder if this really such a good place for a hose instead of rigid tubing

I believe the CJ-5 uses a hose here instead of tubing. My new fuel pump has a different set of vacuum hook ups.

What I am probably going to do is purchase the steel braided lines just in case.

Post by **wesk** » Tue Jul 20, 2010 7:31 pm

The hose tube I was referring too is at the vacuum "T: close to the firewall on left side of engine which takes the suck line from the vac pump, has the line to the distributor and then a short tube stub for the supply hose for the wipers. Everything else in that system is steel except the Army used copper on the distributor vent tubes so the distributor could more easily be moved to set timing.

Both tubes F & Z were steel from factory but were serviced with copper in the field. No rubber hose was used for these lines.