[Slicknick]

I had a pretty rusty situation under the fuel cap, enough to cause a pinhole leak. After fixing it I have discovered the 2 holes for drainage and ventilation are clogged. I’ve tried weed wacker string and guitar String. I can get a little liquid to drip through. Any other suggestions? My next option is sulphuric acid or muratic with a syringe.

 

[Panzermann]

Are they straight? If so, a drill bit should readily work. Do it gently, though - remove the chuck from an electric drill and just use light pressure to work your way through as you turn it back and forth by hand. Sulphuric acid will eat the steel won’t it?

 

[Slicknick]

Are they straight? If so, a drill bit should readily work. Do it gently, though - remove the chuck from an electric drill and just use light pressure to work your way through as you turn it back and forth by hand. Sulphuric acid will eat the steel won’t it?

Yes. sulphuric acid will start to etch the steel. Letting it sit over night with carb cleaner in it. The copper pipe inside curves.

 

[Panzermann]

Not sure carb cleaner will have an effect - it’s essentially a solvent. Phosphoric acid would be the way to go.

 

[Slicknick]

Not sure carb cleaner will have an effect - it’s essentially a solvent. Phosphoric acid would be the way to go.

Thanks for your input.

 

[jagger]

Try the weed whacker line on drill motor. Move it in and out after spraying some penetrating oil in the vents. Acetone and transmission fluid mixed 50/50 is an excellent penetrating fluid.

 

[Slicknick]

Fixed! Thanks again for everyone’s ideas. I let it sit over night with vinegar but was still clogged. Used carb cleaner. Then hit the copper pipe with a heat gun and air compressor from both endz at 80psi. Weed wacker string from both ends as well. It finally blasted out and now both lines are free flowing.