The clutch worked fine, now, there is no pressure when l push the clutch pedal until the last inch to the floor, and it is hard to put into gears when l start it up... Can l adjust it? Do l replace it? What should l do?
How much does it cost?

Replace it cause it might be better and wont have to worry about it going out later

u have a hydraulic clutch on the civic. there r a few possiblities. the first is that it is simply low of fluid. the master cylinder for the clutch is on the rear engine wall on the driver is side. it will be below & to the left of the brake master cylinder. the clutch master cylinder uses the same DOT3 brake fluid as the brake master cylinder. if the clutch master cylinder is low on fluid, then add it & that may take care of ur problem.

if its very low then u have a leak in either the clutch master cylinder or the slave cylinder on the transmission end. typically those cylinders r changed as a set but they do not need to be; u can replace one or the other, whichever is leaking without taking out the 'insurance' by replacing the non-leaking one.

if the hydraulic system is full then the clutch is worn & will have to be replaced. its usually about $400 to replace it plus another $50 to put a refaced flywheel on it (recommended but not necessary)

hope that helps

Best way to check is to remove the rubber insulation covering ur slave clutch cylinder. Your slave clutch cylinder is located right against the bottom of ur transmission housing bell when u first lift ur hood & peer down.

When u press on ur clutch pedal, it transfers ur force into ur master cylinder located against the rear firewall, then across metal thin pipes that push ur clutch fluid into ur slave cylinder.

When u remove the rubber insulation & expose the slave cylinder, u can have someone press on the clutch pedal while u observe a rod protrude from the slave cylinder that should extend & push against the transmission fork.

If ur clutch fluid does not appear to be low while it appears that ur slave cylinders r effectively pushing against the transmission clutch, l am afraid ur clutch disc has worn down & finally needs to be replaced.

You can buy a new clutch disc kit (includes clutch disc, pressure plate, & bearing) for about $100 from ur local auto parts store then find a shop that will install it for u at the best price for just labor.

Otherwise, if u have an air impact tool, a transmission lift (or wide platform jack), & a few other little tools, u can do it yourself & replace ur transmission clutch for free.

If u do not replace ur clutch disc soon, ur transmission will be even harder to put into gears & eventually unable to engage with ur engine rendering ur car from even moving forward or reverse.

Good luck!