when it comes to replace the drum the drum brake , what part do we change? is it the pad only or anything else?
Question about drum brake replacement?
Your question isn't very clear but here goes.
If it's just routine brake wear, then replace the shoes (you might call them pads - don't know which country you're in).
If the drum is worn beyond service limits then replace the drum and shoes.
If any other parts are worn or damaged, the most likely of which is the hydraulic cylinder, then replace that. If the shoes are contaminated with brake fluid then clean the drum and replace the cylinder and the shoes.
Of course, if you mean disc brakes instead...
Question about drum brake replacement?
Much the same as disk brakes. The shoes get replaced, the drums get cut or replaced.
pads,are different from drums.check the pads 1st
the shoes, alot of the times the drums will need replacing or machining and sometimes a spring kit
Mostly just the pad. But it depends on how much the drum is scored and can it be turned to a smooth surface again. Also, sometimes you have to replace the hold downs because they bend and sometimes the star wheel adjuster gets rusty and doesn't work well and needs changing.
You can't tell until it's apart.
you usually just change the brake shoes but there are sometimes you need to change the hardware too like the self adjusters and springs. it,s also a good idea to have the drums turned down too but if they still look good then take some sandpaper and sand the inside of the drums some.
For drum brakes, friction material are called 'shoe'. Those need to be replace. The drum itself need to be measured for thickness to see it they can be re-surfaced, if not they new ones are needed. There are also a lot of springs. Those are changed if needed. Most of the time they are reused.
Drum brakes do not have pads they have shoes.You replace the shoes and if the brake hardware is broken replace them too ie springs hold downs etc.If the drum is scored it should be turned down at a auto machine shop or replaced if the drum is beyond fixing.
