I've been having problems with my bathroom toilet causing"squawking" in the pipes (in the wall) when it flushes. Had a plumber tell me it was due to water pressure (funny...I've been living here for 8 years and it just started) and that I would need a new toilet...decided to live with the noise instead. However, now the spray attachment on my kitchen faucet also "squeals" when used, and the faucet itself has begun to cause a water hammer. I'm thinking my old copper pipes have built up corrosion (house is almost 40 years old and our water has a lot of iron in it) and the supply pressure is fluctuating. Any idea how I can "flush out" the lines without calling in a "professional" and/or the City? (Their jurisdiction runs only to the property line, not to the residence.) 

i have a problem with not having water presure on my hot water side. i have great preasure on the cold side, why is that? how can i fix it with out an expensive plumber bill?