I had to cut the hydraulic clutch line on my 1990 ford ranger (2.3, 2 wheel drive) to get the transmission out and I tried to splice it back together with a union but to no avail. Can I somehow repair it with new line or do I have to buy a new line?

 

Being plastic, I don't think there is a reliable way to attach it back together.
On my 99 the line was held in to the master cylinder by a role pin and sealed to the cylinder with an "O"-ring, so it is replaceable.
Getting the line out of the slave cylinder is the tricky part, and I'm going to assume that you couldn't get yours out because you cad to cut it.

Watch this video.


https://www.rockauto.com/en/catalog/...hose/line,2332

 

Both the line to the master, and the quick disconnect at the slave, are pinned to their respective component with a roll pin and sealed with a double o-ring.

I had a hydraulic shop silver solder a AN fitting to the slave cyl tube, and crimp a line to the master cyl fitting. Had them make a small tube that I attach to the slave after its installed, and on the shop floor. When its in the truck, the master line attaches to that.

Worked beautifully, and no more issues with the quick disconnect and plastic line.

 

If it's anything like my 1995, those clutch lines are nearly impossible to completely bleed when in the truck. The replacement master/reservoir/line assemblies come pre-bled when you buy them. Something to consider when looking for your repair.

 

You can, but it requires taking the master off the firewall. I always bleed via this method. It takes like 2 mins tops