Oil gauge leaking oil on 48 DeSoto

[MarcDeSoto]

Still working on my oil filter and tightening up the lines, but when I crank the engine oil keeps leaking out of the oil gauge connection.  I replaced the line, but the same thing happens.  The line can come out of the fitting about 1/8", but I guess that's normal, but that's where the leak is.   The pic shows the back of the oil gauge and the new line going in.  How do I fix that?   Are brake lines not meant to be oil lines?  

[desoto1939]

on the end of my metal oil line that went into the back of the gage the line had a press fitting that made a small bubble or compression fitting to seal off the hole in the back of the gage.  Check your old oil gage line to see if there was a compression fitting on the end of the metal line. The flared fitting then seals the line when you screw in the connector.

 

Rich Hartung

Desoto1939@aol.com

[61spit]

It is for sure a compression type fitting that goes into the back of the gauge. It is a shorter line that goes into the the back of it and through the firewall. That connects to the flex line at the top of the line coming up from the engine block. Basically three pieces. Hard line from block - flex line - hard line through firewall into the gauge.

[MarcDeSoto]

What is a compression fitting?  Never seen one of those.  

[Plymouthy Adams]

go to your hardware store and ask for 1/8 tubing ferrule.....

[Sam Buchanan]

1 hour ago, MarcDeSoto said:

The line can come out of the fitting about 1/8", but I guess that's normal, but that's where the leak is.  

 

 

No, that is not normal, the fitting is leaking because the flare on the line isn't tight against the flare in the gauge. As others have stated, you need the little brass ferrule that fits between the line flare and the gauge flare. This allows both female flares to seal.

 

Edited May 6, 2022 by Sam Buchanan

[MarcDeSoto]

Do I do that on all the oil filter fittings?  Here is a pic show the new line and the old line.  No ferrule.  

[RobertKB]

This is what the factory used. There is no flare on the end going into the gauge. To me it’s a specialty item. As mentioned the line is long enough to go through the firewall and the other end meeting the hose is flared. 
 

[MarcDeSoto]

Why doesn't my line have that ferrule?  And why is your ferrule on the male end and the ferrule shown by Sam on the female connector?  

[RobertKB]

Your “original” line is most likely not original. The line and ferrule I show is probably the first time it’s been separated from the gauge since new. It’s a spare gauge I have and I took it apart specifically for this thread. I have worked on many old Mopars from 1938 through 1954 and every oil gauge line had that fitting. 

Edited May 7, 2022 by RobertKB

[keithb7]

Who made your flared fitting? There are techniques to be followed then flaring lines, or they are prone to leaking.

[harmony]

Good thread.  Even though mine is fine.  I had no idea what fitting was at the gauge.  Now I know.

[Sam Buchanan]

1 hour ago, MarcDeSoto said:

Do I do that on all the oil filter fittings?  Here is a pic show the new line and the old line.  No ferrule.  

 

No. If you look carefully inside the fittings on the filter elbows, you will see a 'male' flare that mates with the 'female' flare on the end of the brake line. This called an inverse flare because it is the 'opposite' flare to what is on the brake line. No ferrule is needed.

 

But the oil pressure gauge just has a regular flare inside the fitting, no inverse flare. So the ferrule is needed. The same deal is usually found on original fuel tanks where the line attaches to the tank.

Edited May 7, 2022 by Sam Buchanan

[Sam Buchanan]

34 minutes ago, keithb7 said:

Who made your flared fitting? There are techniques to be followed then flaring lines, or they are prone to leaking.

 

Those look like pre-flared lines that we buy at an auto parts store.

[9 foot box]

   I’ve seen it posted in the past, that the gauge uses a special ferrule like RobertKB shows. Mine is the same. My P15 parts book lists two oil lines. One is 3/8”x 24 inverted flare and a 3/8”x 27. Your original line is pipe thread and the new line is straight thread 24. My line nut is 3/8”x27 straight thread not NPT. If you have a parts list book, look in the engine oiling section for what lines were used. I thought that a compression fitting for pilot would work, but I don’t know the thread count.

[MarcDeSoto]

The fittings that they sell at Oreillys are 27 thread on one side and 24 thread on the line side.  when I asked if they sold a 1/8 ferrule, the counterman looked like he had never heard of one before.  He said "do you spell that with a ph?".  If I'm reading you right, I put the ferrule in the back of the oil gauge and screw my line into it.  Correct?  

 

[Plymouthy Adams]

that is why I stated......go to the local hardware store for the ferrule...these are normally serviced at the big box car parts store in line kit or gauge and line kit.  Most all new lines today are plastic and o-ring setups.  Times have changes and so has the manner of install and materials.

[Sam Buchanan]

6 hours ago, MarcDeSoto said:

If I'm reading you right, I put the ferrule in the back of the oil gauge and screw my line into it.  Correct?  

 

 

Correct. Take a brake line with you and get a ferrule that fits the flare on the line.

Edited May 7, 2022 by Sam Buchanan

[kencombs]

14 hours ago, RobertKB said:

This is what the factory used. There is no flare on the end going into the gauge. To me it’s a specialty item. As mentioned the line is long enough to go through the firewall and the other end meeting the hose is flared. 
 

This pic I think is of an original oil pressure line to gauge.  Note, no flare and the compression ferrule is a different shape than a 'normal' hardware store compression ferule.  Those will be tapered on both ends while the pictured one is tapered only on the gauge side.  The other end doesn't fit a normal compression nut but rather the end of an inverted flare nut.

 

I think you may find a replacement from a pilot light gas line or thermocouple  connection for a furnace or gas water heater.  Good hardware store or maybe a plumbing supply.

 

If not readily available you could try a standard one but file or grind the nut to mimic the original as much as possible.  

[RobertKB]

Yes, the original ferrule is firmly attached to the line. I would recommend placing a “want ad” in the classifieds. I would put down year and make of car as line length can vary depending on width of dash. Longer is better than shorter. Someone out there likely has a spare one. Not me as I hang onto spare unique factory parts unless I have more than one. 
 

Always better to go factory than trying to cobble something together that may or may not work. Also, you don’t want to damage the fitting on the gauge itself using inappropriate parts. Then you’ll need a new gauge as well. 

Edited May 7, 2022 by RobertKB

[Young Ed]

This is what you are looking for. The nut and ferrel start out one piece and snap into 2 on first install. 

 

 

 

[desoto1939]

39 minutes ago, Young Ed said:

This is what you are looking for. The nut and ferrel start out one piece and snap into 2 on first install. 

 

 

 

 Young ed  do you have a part number for these connector and also where did you get yours.  I was tryting to explaind to Marc in my reply about the ferrule at the end. even contacted several MoPar venders about the oil pressure gage and this special line end and they did not have any or even know about the special end.

 

Rich Hartung

Desoto1939@aol.com

[Dodgeb4ya]

This same topic came up a few years ago and Ed found those special ferrule nuts..cannot remember if a # was posted then.

I used one on my truck guage line...no leaks.

A regular compression ferrule will leak.

[9 foot box]

   It looks like a Parker 61HD-3. But I don’t know if the thread count is correct for his gauge. 

[Sniper]

17 minutes ago, 9 foot box said:

   It looks like a Parker 61HD-3. But I don’t know if the thread count is correct for his gauge. 

Looks like 3/8-24

 

https://www.mfcp.com/product/fittings/compression-pneumatic/hi-duty/parker-61hd