I'm installing an aftermarket oil pressure and water temp gauge set in my 78 but I'm not sure about the hose for the pressure gauge. It's a kit from summit and came with a Teflon tube so I put the compression sleeve and the threaded fitting on the hose and screwed it up to the back of the gauge but I can pull the Teflon tube out of the fitting pretty easily. Is it supposed to do this or should I not be able to pull it out? I'd really prefer not having oil fly all over my cab.

 

You should NOT be able to pull the hose out the back of the gauge. Are you sure you have the compression sleeve on correctly (if there is even a difference)?

 

You should not be able to pull it out of the compression sleeve. When tightened correctly, the sleeve compresses slightly and locks onto the flexible tube. I was nervous about using the nylon or teflon tube but I've never seen one have a problem. I've installed quite a few.

 

Thought about it and are you sure you have the tube seated/flush all the way on the back of the gauge fitting and are you sure the compression sleeve is smooth and has no burrs?

And is it seated in the threaded fitting correctly?

 

Did you even put a compression sleeve (ferrule) between the nut and gage adapter on the tube? You should have had a tube nut, a sleeve (ferrule) slid up on line, and insert tube into adapter and tighten nut thus squeezing the sleeve (ferrule) onto line.

Some use a barrel shaped sleeve (ferrule) that works either way, others come with a sleeve (ferrule) that is more pointed on one end and flat on the other, the point goes towards the engine or gage and away from "line".
Some others are two piece affairs, with an adapter and a screw in nut that has the compressable part made to it (I don't use these myself).

I've used the plastic tubes for oil gages for 45 years, the one on my '77 has been on there since 1986 and maybe twice, I have cut the end and used a new sleeve (ferrule) and put it all back (I've never seen one break clean, but I have found a time or two a weeping leak).

You can use copper, it costs more and copper will fatique crack if you don't provide loops between moving and non moving parts (like between engine and firewall hole).

 

FYI..... It's called a "capillary tube".

 

not sure if mine had one of these or not, but they should have this part. If it doesn't you can buy them buy their self at hardware stores. It goes in soft tubing to give a more positive bite from the collar.

http://i00.i.aliimg.com/img/pb/942/7...748942_990.jpg

 

The compression sleeve is called a ferrule. You can also get a fitting that will allow you to push the line into it with no fittings to tighten. I recommend this for the attachment to your gauge for ease of completion. You could probably do it at the engine, but I don't know about the heat. The link is for general purposes only, but here it is:

SMC Male Connector,1/8 In,Tube x NPT - Push to Connect Tube Fittings - 4GLA2|KQ2H01-34S - Grainger Industrial Supply

Personally, I just went with an electric oil pressure gauge. Sender unit screwed right in and wires to the back, just like the other gauges.

 

I personally don't like the plastic tube even though I've never really had any problems with leaks. When I installed new gauges last time I upgraded my hoses with this braided line kit from Speedway. Works great and looks good too.

Braided Pressure Gauge Line Kit - Speedway Motors, America's Oldest Speed Shop

 

I stand corrected.... it's not a capillary tube. Thanks tbear.

 

Funny edit, Tbear

 

Accel has a brass line to replace the teflon line. The teflon line is prone to kinking and crushing. Normally, there's no issue with them, but if you want piece of mind, get the brass line kit.

 

I'm going to go with a braided stainless line eventually. I'm positive it was put together correctly because I found out my problem. I only had it finger tight... Apparently the purpose of the compression sleeve didn't quit register until after reading the comments here. It was obviously one of those days.

 

Haha ..... Glad you approve!

When I wrote that post initially I was looking for a word that escaped me, so I usesd what I used ..... and then you brought it back to me.