Writing up a few suggestions about this type of repair.

On my 85 240 I am in the middle of replacing my fuel filter.
This is 39 years old so all mounting screws were to replace and that's fine, understandable.
So I was at the pump + filter assembly removal phase. Working on the last step when you want to disconnect the output end of the filter. That is the last connection to undo if you want to remove the whole assembly off the car.
While I was unscrewing the banjo fitting at the output end of filter I omitted to hold the banjo fitting in place while applying major torque to the screw. So I ended up bending the nylon tubing badly right at the joint with the fitting.
I knew I had to redo this tube-fitting joint before putting the assembly back in place.
I have read the above steps from Steve. They guided me nicely through the repair at that banjo fitting - tube joint.
In the particular case where the damaged tube is at the fitting I can testify you can do this fix right on the floor. You should not need to remove the whole line between filter and fuel rail.
Going thru each previously posted steps: In the case of a repair right next to the filter fitting. You could do as follow:
1- No need to remove the line from the car.
2- You can reuse the line. Just cut off the damaged line end. Loosing about 1.25 to 1.5 inch. Not a problem.
3- To clean off the plastic tubing from the metal fitting I recommend you use a heat gun ( I would not use a torch ). With long nose pliers you should be able to grab the extra tubing that extends passed the fitting barbed end. It should pull out easily once warmed up.
4- Get two pieces of 3/4" thick hardwood flooring, about 2 inches in length should be fine. 3/4" Hardwood flooring comes with two longitudinal grooves under the flooring piece. Place the two pieces with the grooves facing each other.
Align the grooves and clamp on a vise tightly. Get a drill 1/4" diameter. Drill thru the two sets of grooves. You only need one set but since the two blocks are not attached together it is easier to not have to remember which way you arranged the blocks.
5- Get a C clamp or wood-working clamp. I like the wood working type clamp because you can adjust quickly and they offer very decent clamping force.
Go to the floor near the tube end.
You need to place the tube inside the two blocks, into the grooves. Let 1/2 inch of tubing extend passed the blocks. Clamp the two blocks and apply the load over the grooves with the tube.
6- Lubricate the banjo fitting barbed end with light oil like WD-40 or PB Blast (any loose-nut oil). Manually present the barbed end to the tube. Get a mallet with plastic hitting end. The end of the mallet should be hard plastic. Don't use an end that is too soft like rubber end. You could loose control and bend the tube.
Then with one hand, hold firmly the blocks with clamp against the floor. With the other hand use the mallet to tap carefully AND IN-LINE with the banjo fitting into the tube.
Once the fitting moved 1/2 inch inside the tube, release the blocks to allow another 1/2 inch of tube to extend passed the blocks. Clamp and repeat the insertion with the mallet. Continue the process until the tube touches the shoulder passed the barbed end.
I was surprised to see how easy it was to put together.

In hope this helps. I appreciate all the help I get from this forum and thought I should work harder on my end to pass on some of my own discoveries.

Richard

Writing up a few suggestions about this type of repair.

On my 85 240 I am in the middle of replacing my fuel filter.
This is 39 years old so all mounting screws were to replace and that's fine, understandable.
So I was at the pump + filter assembly removal phase. Working on the last step when you want to disconnect the output end of the filter. That is the last connection to undo if you want to remove the whole assembly off the car.
While I was unscrewing the banjo fitting at the output end of filter I omitted to hold the banjo fitting in place while applying major torque to the screw. So I ended up bending the nylon tubing badly right at the joint with the fitting.
I knew I had to redo this tube-fitting joint before putting the assembly back in place.
I have read the above steps from Steve. They guided me nicely through the repair at that banjo fitting - tube joint.
In the particular case where the damaged tube is at the fitting I can testify you can do this fix right on the floor. You should not need to remove the whole line between filter and fuel rail.
Going thru each previously posted steps: In the case of a repair right next to the filter fitting. You could do as follow:
1- No need to remove the line from the car.
2- You can reuse the line. Just cut off the damaged line end. Loosing about 1.25 to 1.5 inch. Not a problem.
3- To clean off the plastic tubing from the metal fitting I recommend you use a heat gun ( I would not use a torch ). With long nose pliers you should be able to grab the extra tubing that extends passed the fitting barbed end. It should pull out easily once warmed up.
4- Get two pieces of 3/4" thick hardwood flooring, about 2 inches in length should be fine. 3/4" Hardwood flooring comes with two longitudinal grooves under the flooring piece. Place the two pieces with the grooves facing each other.
Align the grooves and clamp on a vise tightly. Get a drill 1/4" diameter. Drill thru the two sets of grooves. You only need one set but since the two blocks are not attached together it is easier to not have to remember which way you arranged the blocks.
5- Get a C clamp or wood-working clamp. I like the wood working type clamp because you can adjust quickly and they offer very decent clamping force.
Go to the floor near the tube end.
You need to place the tube inside the two blocks, into the grooves. Let 1/2 inch of tubing extend passed the blocks. Clamp the two blocks and apply the load over the grooves with the tube.
6- Lubricate the banjo fitting barbed end with light oil like WD-40 or PB Blast (any loose-nut oil). Manually present the barbed end to the tube. Get a mallet with plastic hitting end. The end of the mallet should be hard plastic. Don't use an end that is too soft like rubber end. You could loose control and bend the tube.
Then with one hand, hold firmly the blocks with clamp against the floor. With the other hand use the mallet to tap carefully AND IN-LINE with the banjo fitting into the tube.
Once the fitting moved 1/2 inch inside the tube, release the blocks to allow another 1/2 inch of tube to extend passed the blocks. Clamp and repeat the insertion with the mallet. Continue the process until the tube touches the shoulder passed the barbed end.
I was surprised to see how easy it was to put together.

In hope this helps. I appreciate all the help I get from this forum and thought I should work harder on my end to pass on some of my own discoveries.

Richard

Hmmm, Good info there. I always figured the stuff was like heat shrink. Apparently not.