Can't get wire from old light out

[sjoefl01]

Hoping for a mechanics trick.
I have a really old Amerilite pool light that is 12v and for some insane reason they put the wire in half inch electrical PVC. The wire is probably #12 and I am guessing near 100ft long. I believe all of the conduit is under concrete. When I had the liner installed the guys gave up on replacing the light because they could not get the old one out. They thought the conduit was probably broken underground. As I look at how tight the wire is in the half inch conduit I am thinking that it is just all bound up. I could probably get a a water hose to the fitting on the other side and pass water through it. I thought about loading the pipe with dawn dish washing liquid but I don't thin that would be a good idea since the water will be mixing with the pool water.
Any ideas?
Something slippery that would not contaminate the pool water?

There is not enough wire on the pool side to get the light all the way on the side of the pool. The ring is horribly corroded and the only replacement I could find was Pentair which is a completely different design. I am not sure it would pull the gasket tight enough to keep the water out. The light is currently flooded.
Any help would be greatly appreciated.


Update:
So I spent the afternoon working on the problem. I made an adapter so I could hook a water hose down the line. I passed a lot of water through the conduit and could not move the cable either way. I poured a lot of dawn dish washing liquid and put just a a little water in the pipe until I could smell the soap in the water bubbling up. I tugged really hard and nothing.
I decided to see if if I could repair the existing Amerilite fixture. I have a new gasket. Although the fixture is corroded I think I could get it to seal. I drained a lot of water from the pool so I could dry the fixture and see if I could make the light work. . I found the problem. The little copper tab that makes contact with the center pin of the bulb has broken off. About all that is left it a tiny piece of copper and the rivet. If I could get it out of the pool I might be able to drill and tap the rivet and make a new copper tab. I don't really think that is going to work very good in the water. I am still looking for brilliant ideas. I can think of some ways to add more leverage to the wire pulling effort but that seems like one of those things that end up viral on Youtube

 

[z3540i]

There may be a kink in the wire causing the tightness. Suggest pushing as much of the wire into the PVC from both ends to "unkink" the wire but make sure you have enough outside to still be able to pull on the wire. Then pull on both ends at the same time (2 person job). You may have to try this several times to unkink the wire. Also, when you pull the wire out, have someone feed the wire into the PVC (may help if there is a 90 degree bend anywhere along the PVC). Unfortunately, if there is a sharp bend in the PVC, it may be impossible to pull it out. You may have to call in the experts (

Good Luck!!

 

[Rocket J Squirrel]

What my PB did for leverage was to wrap the wire tightly around a pick-axe handle (at the lamp end) and use the axe blades as handles with gloves on. It was brute force turning that axe, standing in my mostly drained spa, but it eventually worked.

100 feet is a lot of wire, though. Mine was probably 20 feet from the lamp to the junction box. Yours may be past DIY level.