Problems in the clutch.

Hi Luis,

There are quite a few factors that could be at play here, so I'll try to go through the possibilities with you.

First, as @jayeff has already mentioned, you could be low on hydraulic fluid. Just like your brake system, the hydraulic clutch works by transferring pressure from the master cylinder on the firewall to the slave cylinder on the transmission. If it doesn't have enough fluid, it won't be able to build up the needed pressure to operate the slave cylinder fully.

If the fluid level is low, you'll want to top it up with the correct fluid for your car. One problem is that a low fluid level can allow air into the system that has to be removed by bleeding the clutch, exactly the same procedure as bleeding the brakes. That should remove any sponginess in the system.

A similar situation can come about due to leaks in the hydraulic system. The fluid is kept in by rubber seals, which can wear out over time and allow the fluid to escape past the seal. Check the master and slave cylinders for any signs of fluid leaking, especially around the shaft where the clutch pedal goes into the master cylinder and where the rod that activates the clutch pressure plate comes out of the slave cylinder. There may be a rubber cover over either end that you might want to pop off temporarily in order to check for the presence of fluid there.

That should address the "sponginess" issue, but that may or may not be related to the pedal height issue. Over time the height at which the clutch pedal engages will change as the pressure plate inside the transmission wears down. Generally there is an adjustment in the clutch that compensates for that wear. Over on the Aveo forums, one user gave the following information regarding adjusting the clutch.

Help with clutch peddle

I took a look at the Manuals I have, and here are the Specs that it has:

Clutch Pedal Freeplay: 0.4-0.5 Inches

Clutch Pedal Travel: 4.7-4.9 Inches

you adjust it by loosening the locknut and turning the Clutch Master Cylinder Pushrod until you pretty much get the specs I have listed.

Keep in mind that at some point the adjustment will no longer be sufficient, and at that point it is probably time to replace the clutch. That work normally includes putting in a new pressure plate, clutch disk and throw out bearing.