I changed my car Front disc brakes (Ford Fiesta MK4) but now my braking seems slow and soppy?

I changed my car Front disc brakes (Ford Fiesta MK4) but now my braking seems slow and soppy? - 1

They need time for the pads to bed in, they will start working properly after around 200miles.

Need to have changed pads at the same time as if not then the old ones will not be flat enough to engage the whole disc surface.

Looks like you did not bleed the brake lines. You may have let air into the brake lines.

While Timbo could be right, most cars can handle you changing just the front or just the back brakes, as long as you change them in pairs.

Who is Jack is right, but there's a much faster way to do it. It's unsafe to have spongy brakes for 200 miles, so I'd do it this way: On a stretch of road where you can do this, get up to 25-30 mph and hit the brakes hard to come to a stop. Not hard enough to engage the ABS or lock the tires, but you should stop quickly. Reverse the car to 10-15 mph and do it again. You'll probably start to feel the brakes catch easier. Do it forwards again and you should be good to go.

If that doesn't work, check online or a Haynes/Chilton manual to see if there are other procedures you need to follow when doing the brakes. Some need to be bled after a pad change. It might also be recommended that you resurface the rotors.

Did you change the pads and discs, or the pads alone?

If both did you remember to clean the disc surfaces with brake cleaner (or petrol) to remove the protective varnish? If not then you'll need to remove the pads and grind off the top 1mm from the friction surface (ideally by using a milling machine) and will need to clean the discs properly. After that it still takes about 250 miles or so to bed the pads and discs together during which time you must avoid harsh braking.

If just the pads, did you check the discs were not deeply scored and did you check their thickness? Badly scored discs must be refaced smooth, and that sometimes takes worn discs so close to their minimum thickness that they need replacement anyway. If in doubt just change them; front discs typically need changing with every alternate pad change but if you've been a bit silly and fitted harder "racing" pads for street use then the discs need changing with every pad change. Either way, fitting new pads to old discs always leads to a longer bed-in period unless the discs were re-faced, and it can easily be 400 miles.

One final possibility is if you were a bit too generous with the anti-squeal grease whether you used copperslip or thermally conductive ceramic paste such as CeraTec. If you don't use the bare minimum needed it liquefies under braking and migrates into the disc. If that's happened you have to clean it off with brake cleaner/petrol and throw away the pads and replace them; there's no safe recovery for pads which have been contaminated.

Everyone seems to be in the "bed in" group. I'm going with that also but I need to ask, did you buy the cheapest set of pads you could? That could be the reason if you did.

Are you an experienced mechanic? If not, then you probably did something wrong

Brakes are cleaned with "Brake-Kleen" This is not a petroleum product. Petroleum products(gasoline) is OILY. You don't want to use that on the drums or steel rotors or on the brake parts. Do it right, or don't do it at all.
Chances are the rotors are glazed and they need to be turned or you missed the fact how the caliper works in your car and only one side is pressing on the rotor… Instead of both "PINCH" the rotor from the front and behind the rotor. If only one side is working and the other is not, then brakes are nearly non existent. See a brake mechanic and see how he does it and you remember forever.