2002 Kia Sportage Car spongy clutch pedal Answer The clutch pedal is very spongy, and sometime has not pressure on the pedal at all when the vehicle... (More) The clutch pedal is very spongy, and sometime has not pressure on the pedal at all when the vehicle is running and I can't get it into gear. Also the clutch was slipping and very slow to get moving from a dead start, a short time later it began working a little better. Should I replace the clutch and pressure plate or is there an issue with the hydraulic's??

Just a thought since my sons 07 kia was having trouble starting a couple months ago. His is a standard shift, voltage good, I reached under dash and pushed clutch pedal switch plunger button in. Punt in neutral and pulled emergency brake and turned the key, cranks right up. It was not the switch, the pedal linkage/rod to the pedal has a flat plate off to the side the plate which pushes in the clutch pedal plunger to the switch. The plate has a hole in it but I did not know what goes in the hole, I put a flat bolt and nut on it . It has been cranking fine for a couple months. The switch plunger was going in the hole sometimes and the car would not start. The clutch pedal switch will not let the car crank unless the clutch is pushed in. If your car is an Automatic the neutral safety switch on the transmission will do the same thing it has to be in park or neutral. I am having second thoughts I am pretty sure it was clutch pedal switch but having a odd thought it may have been brake pedal switch. You might even be able to put duct tape over the hole till you get the correct plug for the hole if this is your problem.
3 links which may provide some help
https://www.youtube.com/watch?v=1iPCIqrmDBs
https://www.youtube.com/watch?v=FKpMoPoBC2o
https://www.kia-forums.com/threads/2011-sportage-wont-start-sometimes.324082/

would be wise to replace both clutch master and slave cylinder

there is no pressure regulator in the front brakes system. The harder you press the pedal the more braking action. There is an equaliser in the rear brake line to prevent rear lock up under moderate brakes and this is all over ridden by the ABS system when it sensors a locked wheel situation.

Top up your fluid, if it works look for a leak on the cylinder, master and slave

after the nuts and bolts are out your kit should have a allinement tool for pressure plate and cluch disk did kit come with throw-out and pilot bearing would be a good time to change them

If you need further help, I’m available over the phone at https://www.6ya.com/expert/mike_9693b5ad75773352

did you bleed system?

Sounds like poor work, and you may have a bad clutch master or slave cylnder, being it was probably not bleed properly.

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/sean_54c3a3dc48a7773c

Depends on mileage.
If it's due to be changed, replace all parts, but I'd guess a hydrulic issue or adjustment problem.

Need more info on what the trans is doing , or not doing. No chance that brake fluid cools or lubes your transmission. The only possible connection is that your clutch is hydraulic which would use brake fluid , but two totaly different systems. Does your clutch feel funny?

Might be time to change the clutch.