Assembling the Stainless Steel Lined PTFE hose fittings

[rustystud]

I told Aaron (peashooter) a while back (OK maybe a year or two or more !) that I would post some pictures of how to assemble the reusable (field repairable) Stainless Steel lined PTFE hose fittings. Well I was cleaning my computer ( too much junk !) I came across these pictures. So I will explain the process. There are 3 pieces that make up the fitting. The main body, the ferrule, and the clamp (at least that's what I call it ) . You first slide on the clamp over the tape, picture 3 ( I'll explain later) . Remove the tape, then using a small screwdriver gently pry back the stainless steel braid from the Teflon hose ( picture 4 ) . There must be NO strands left touching the hose ! . Then push on the ferrule (pictures 5 and 6 ) . It will take a little force to do this. The hose will bottom on the inner lip of the ferrule. Then again using the round shaft of the small screwdriver gently force the hose into the ferrule walls until it is a smooth surface looking straight down the hose ( pictures 7 and 8 ). Now use a Teflon based spray to lube the hose and insert the main body. You will have to push and twist at the same time using considerable force to get the body to seat all the way in ( picture 10 ) . Do NOT bend the hose assembly while doing this ! It must be a straight push in or you risk dislodging the ferrule.

 

[rustystud]

Once the main body is all the way in, bring up the clamp and start threading it on the main body ( use some spray on the threads ) . I use a vise when at home to hold the main body, but a wrench will work just as well in the field. Also note that the hose will start to turn after a few threads have been tightened. This is due to the fact that the braid is gripping the ferrule. Just make sure the hose can move freely and does not become kinked . Tighten the clamp until it touches the brass on the main body ( picture 3 ) . Do not over tighten it ! 5 to 10 ft lbs is all it should take once it touches the brass. Pictures 4 and 5 show how the hose is cut. You must use a high speed cut off wheel to cut the hose. Tape the area that will be cut ( I use electrical tape ) with 2 wraps . Any more and it well be difficult to install the clamp over it . Then cut it at a 90 degree angle . The straighter the better. Blow out the hose to remove any debris. That's it !
The last picture is the spray I use. "Tri-Flow" is also a good product, so is "LPS 2" .
Hope this helps someone.

 

[peashooter]

Thanks for the step by step rustystud. Are these Parker fittings you are demonstrating with? Are the Weatherhead brand ones done the same way? I had bought a SSP brand Braided hose setup a while back and it had a little different connector without a separate Ferrule, never knew how tight to get clamp onto the main body... thank you.

 

[Woodsplinter]

Thanks for the great information! Are these used for the brake system?

 

[Jeepsinker]

Fuel system

 

[welldigger]

And air systems. Nice write up rusty.

 

[JasonS]

and power steering. Speedway Motors has a nice selection and good prices.

 

[rustystud]

This style hose (PTFE stainless steel wrapped ) can handle up to 3000 psi working pressure in oil, fuel, and many chemicals including brake fluid. It can also handle around 500 degrees temperature. At work we use this type of hose on almost anything. It also handles vibration extremely well. It also never ages. The hose will last forever if not damaged. That is why I used it on the deuce fuel system and many oil lines.

 

[Lonnie]

1 thing I can add is that after cutting the line, I suggest deburring the edge of the teflon with a razor knife. It allows the Ferrule (olive) to seat better on the end of the line.

They also make aluminum hose ends. If using these I recommend motor oil on the threads to prevent galling.

 

[rustystud]

1 thing I can add is that after cutting the line, I suggest deburring the edge of the teflon with a razor knife. It allows the Ferrule (olive) to seat better on the end of the line.

They also make aluminum hose ends. If using these I recommend motor oil on the threads to prevent galling.

Yes, if you don't get a good straight cut on the hose sometimes you need to use a knife to clean it up. On the aluminum fittings I use anti-sieze, but I'm sure motor oil will work OK .

 

[Neophyte]

Awesome write up!! I used a the same hose for fuel lines on a DD453 I rebuilt over the winter. The critical part was cutting the braided hose with a fiber cut off wheel (took a couple tries to figure out that was the best method). Once the braid comes undone.....impossible to connect the compression fitting on.

 

[rustystud]

Awesome write up!! I used a the same hose for fuel lines on a DD453 I rebuilt over the winter. The critical part was cutting the braided hose with a fiber cut off wheel (took a couple tries to figure out that was the best method). Once the braid comes undone.....impossible to connect the compression fitting on.


View attachment 514280

Good looking engine you have there Neophyte .

 

[Neophyte]

Thank you. I wish this write up was available 6 months ago.......I must of cut the braided hose 4 times before getting it right. I used 8an fittings throughout the fuel system...worked like a charm. These PTFE hoses are a huge step up from the old rubber hoses.

 

[rustystud]

Thank you. I wish this write up was available 6 months ago.......I must of cut the braided hose 4 times before getting it right. I used 8an fittings throughout the fuel system...worked like a charm. These PTFE hoses are a huge step up from the old rubber hoses.

They are the "cats meow ! " I see you used the aluminum fittings. I always just use the steel ones, that way I can recycle them to use on hydraulic systems if I need to.

 

[rustystud]

Though come to think of it aluminum would be better with diesel fuel. I always see rust on diesel fuel fittings and I have never found out why ! At work I just use "anti-sieze" on the threads to prevent rust buildup. They do make Stainless Steel fittings for PTFE hose though they are extremely expensive !!!