HOW DO I TAKE APART MY DELTA 4578-LHP TO FIX A LEAK?

http://www.deltafaucet.com/parts/id-my-product/index.html?reset=true#wiz you should be able to track down the one you have on this "troubleshoot your product
'

with the model number you should be able to find one easily on ebay or amazon. ask the seller any questions before purchase if unsure.

at the bend in the faucet handle there is a hole that has a set screw in it

It sounds like you are referring to the valve assembly. It sounds like the line broke where it is soldered into the base of the valve assembly. You may be able to solder the line back on using a union, but if not. it may be easier and cheaper in the long run to just replace it.

Go to the link below then click on download. This will bring up a pdf file for the Delta 14 series. Scroll down to page 5 for instructions from Delta on how to adjust the temperature after removing the handle.

http://www.deltafaucet.com/customersupport/documentation/T14430-LHP%20H74%20A74.html?document=mi&documentIndex=0

the retaining nut,located under handle may not be screwed down all the way.this happened to me on similar / same faucet's.so try this and see,nice and easy

To fix the leak in delta faucet is have a repair kit for
Delta 470-WHRS. The repair kit consist of O-rings
replacement. Otherwise, you have to buy a replacement
for your Delta 470-WHRS.

yes . when buying the faucet dont forget to buy stainless steel suply lines for water line connection.

Turn the water off at the faucet, remove the handle and the retaining nut that is apart of the trim. You will see where you can use a wrench to remove it. The ball assembly will come right out and you can replace the washers right below it. Put it back together and if needed, tighten the tension ring that is on the retaining nut (usually grey or white in color) so it won't leak water around the ball stem. Good luck.

one word clr. let it sit in the solition over nite it will remove scale and deposits. you can find clr at lowes, home depot, walmart, etc.