70 D100

If your still having trouble getting the rings unstuck, clean and dry the cylinders all the way out and rinse out the oil with Carb, brake, or electrical cleaner. Get it outside, pull the oil pan, and get a flat plastic tote pan under it. Pour in white cleaning vinegar about three inches above the pistons closest to BDC, add three tablespoons of bar keepers friend powder(Oxalic Acid), mix in and then stir in about an inch of naval jelly. Mix thoroughly. Get a cheap turkey baster to siphon some out and distribute to other . Leave a little room. Get your gloves and goggles on, get upwind, and add a tablespoon of muriatic acid to each cylinder. Cover with another flat tote and leave overnight. I once did this with equal parts straight cleaning vinegar, muriatic, and a hydrofluoric acid aluminum cleaner but its really nasty and not good to be around. It turned the pistons into jelly and made a fantastic hazardous mess to clean up. This is a lot milder version of the same, it primarily attacks the rust in the cylinders and rings. Once done, suck everything back out with the turkey baster and put it into a polyethylene jug (windshield washer fluid jug) for disposal (makes great drain cleaner) Rinse cylinders down with hot water three separate times, siphon the water out with the baster and add to the jug. Dry and get some oil back in the cylinders. Try the 2X4 and hammer again. Keep oiling and working back and forth between cylinders. It takes some effort but eventually you'll be able to rotate it around to get the other clutch bolts out.