69 Oil Pressure Gauge Line Leak

[Driftwood]

I ordered a Zip plastic oil pressure gauge line replacement kit and am having trouble getting the end to seal. I started my engine and oil was coming out the middle hole in that brass nut. Wondering if anyone else has monkeyed with this and has some tips.

Besides the plastic line, there are three brass pieces per end with the kit-- a cylindrical ferrule that slides inside the line, a slotted piece of brass that you crimp down onto the line and ferrule, and the threaded brass nut with a hole in the middle.

I'm wondering if it matters which way the slotted piece is facing. In other words, should the smooth end opposite the slots face the nut or the end of the line? Also since I don't have a warm fuzzy feeling about this whole setup, I'm interested in a better kit or totally different setup if anyone has suggestions.

Previously someone had mentioned running a copper line instead. What parts would you need and where could you aquire them?

Thanks for any help,
Andy

 

[Driftwood]

Followup question

I suppose the other question I should ask-- where is the oil actually sealed off-- at the contact between the engine block fitting and the slotted piece? And I assume you slide that ferrule all the way into the line. Should the slotted piece be situated at the very end of the line, or back set a little? I know it's a lot of question for 3 little pieces, but without a picture or instructions I'm questioning if I assembled it correctly. Thanks.

 

[cruisin-davey-g]

Hi: I usually just put the ferrule on the end of the neropreme tube push the line into the guage until the ferrule seats against the guage fitting & then screw on the nut & tighten it down, making sure I don't over tighten. Make sure you put the nut on the tube first before the ferrule (I always forget. My mind's not what it used to be )I really don't know about that crimping end your talking about without seeing pics. You may or may not need it.

Dave

 

[Driftwood]

From what you said, now I think I understand why mine is leaking. The ferrule goes all the way down into the fitting to make the seal. I was putting the crimping piece right at the end of the ferrule, which was keeping the ferrule from inserting all the way in. I assumed you needed the crimping piece to keep the ferrule from falling out of the tube and into the engine (that's the end that was leaking). I'll either move the crimp piece back on the tube a little to let the ferrule go all the way in, or maybe just try it without the crimp piece like you and see what happens. I guess if the ferrule is hitting up against a fitting to make the seal it can't fall down into the engine. Thanks for the info.

Andy

 

[Driftwood]

Wait..now that I've thought about it a minute...I don't see how your setup works. The oil line fits through the center of the brass nut. When you tighten down the nut, what is still pressuring the ferrule up against the fitting? After you tighten down the nut, doesn't the line easily slide in and out, at least until the ferrule hits the hole? Seems like a lot of slop and that it would leak. Maybe that crimp piece is supposed to be crimped back far enough on the line to let the ferrule seat up against the fitting. Then you tighten the nut down against the crimp piece. So the crimp piece is holding the ferrule tight up against the fitting???

 

[cruisin-davey-g]

OK; without seeing exactly what you're doing, it's hard to tell what's going on there. I thought you were trying to fit it to the rear of the guage. Sorry 'bout that. But, It should work on the engine side as well. What happens, is when you seat the ferrule into the block fitting by pushing the tube in so the ferrule seats, when you tighten up the fitting nut, it will cause the ferrule to crimp slightly against the tube so that if it's tightened correctly, you shouldn't be able to pull the tube out of the nut. That's why it's important that you don't over tighten the nut, as you will crush the ferrule too much. At least that's how I've always done it.

Dave

 

[Driftwood]

Ok-- I didn't realize the nut tightens against the ferrule. Now it makes a lot more sense. I'll look at it tomorrow and see if I can get it to work. Thanks for your patience.

 

[ChuckG]

You don't separately crimp that little ferrule....you let the pressure of the nut do the crimping for you. It's a simple compression fitting. If you crimped the ferrule with pliers, etc., you might have boogered it, scored it, gouged it to the point that now it won't seal. The copper plated steel oil pressure lines work the same way, except there's no piece to slide into the open end. Chuck

 

[SwaveDave]

After having my plastic oil pressure guage rupture and squirt oil all over the insides of my new radio/tape player...i went with 1/8" copper ; its silly to me to think GM engineers would choose plastic containing high pressure oil that is run so close to the exhaust and is susecptible to vibrations .

At any rate...on compression fittings, i find if y ou apply a little bit of Teflon Pipe Dope to the male threads of the fitting...it helps seal it better. Start on the 2nd or 3rd thread with the Dope.

Dave

 

[cruisin-davey-g]

Swauve Dave: The copper tube is a nice thought for this type of application. But, because copper tubing is not flexible like the neopreme (plastic) tube, it can run the risk of breaking at the contact points Where it goes into the nut (engine side), because of the movement of the engine itself in the compartment (torque, vibrations, etc.). Sort of like mounting the trans dip stick tube to the firewall. I guess that's why motor mounts are made out of rubber & are flexable.

Dave

To Chuck: You are right about nt manually crimping that little ferrule. Let the nut & compression end of the brass fitting in the block do the crimping work. Like you said, it is a compression fitting. I'm really not too sure what Andy is talking about in the way of that part he is refering to as a crimping end thingie(?) . These types of compression fittings are the same ones used in gas & plumming connections where a compression fitting is called for. Take care!

 

[SwaveDave]

Crusin,

I dont suggest that you run the copper line taught or fasten it to anything on the firewall ; it works fine if you make a small spiral coil in the tubing, or, just have lots of slack in it to allow for engine movement . Where it goes thru the firewall, it should be run in the rubber grommet that has wires going thru it already, and then to the pressure guage with some slack in it still. Mine has worked fine .

Dave

 

[Driftwood]

Picture of parts attached

Thanks for the info. The kits the various Corvette companies are currently selling must be different than ones you guys have used. That ferrule completely slides through the hole in the nut. So the nut would not compress the ferrule when tightened down. That "crimp" piece is a brass cylinder about 1/2 the length of the ferrule. One end of this cylinder has equally spaced slots cut into it (as if for crimping). The slots are about 1/2 as long as the piece itself. The hole in the cylinder is just larger than the tube. And the end opposite the clots has a flat surface, as if for a possible seal.

So I would assume you slide this piece over the tube and ferrule, then squeeze the slotted end a little to hold the ferrule in place. But this crimp piece is too big to actually go down in the engine block fitting to make the compression seal. Then when you tighten the nut, the nut tightens against this crimp piece.

I've attached a photo of the parts. If anyone can tell me how this is supposed to work I'd appreciate it. Or if I can run to a hardware store and get some parts (maybe like you guys used) that would work, that would be great also! Thanks.

 

[JohnZ]

Slide the big nut over the line first, then the slotted ferrule; then insert the thin brass tube into the end of the line. Insert the end of the line into the fitting, making sure it's fully seated, then slide the ferrule down into the fitting, followed by the nut, and tighten the nut. The end of the nut will compress the ferrule around the line, which is prevented from collapsing by the thin insert tube.

Don't even THINK about using copper tubing instead - it will work-harden with engine vibration and eventually fracture. The OEM metal tubing used on C2's wasn't copper, although it looked like it - it was copper-plated STEEL tubing.

 

[SwaveDave]

Ill bet it wont fracture in my lifetime...and i should be good for another 40 years (or so...) Lord willing.

 

[cruisin-davey-g]

"Good Lord Willing..........And The Creek Don't Rise!"

 

[69vettester]

All I have about this is a "BIG" Ditto about not using copper tubing, You'd have oil pumping out the cracked tubing in no time.