When you say keep breaking, are they broken off in pulley now? How are you planning to remove broken bolts? Can you grab them with a pair of locking vise grips, or equivalent. If you are lucky enough to get broken bolts off, use only top grade 8.8 or equivalent hardened bolts. If your pulley is frozen, and heat and penetrant aren't getting it to budge, you may have to tow to a pro machinist. They have trick tools and techniques that might work.You might try a different harmonic balance puller. The front of yours may be damaged, or missing something. Keep us posted as to your progress.
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