2G Clutch FCU Removal

What is an FCU?   An FCU is the fluid collection unit / flow control unit, a buffer in the clutch fluid lines, that pools fluid to smooth out clutch pedal engagement.

Why should we remove it?   In order to make sure the clutch fully engages in performance situations.

**Do this Mod AT YOUR OWN RISK**

This will most likely totally void your powertrain warranty, if it is noticed by the dealer. Keep all parts...

If at any time you feel uncomfortable stop and get help. I mean mental help, this is very easy. (small joke, please do not take offence)

Removing the FCU

Locate, beg for, borrow or steal the following items:

  • 10mm line wrench (must be a line wrench. Sears has them.)
  • Dot 4 brake fluid (small jar is fine) this is what the clutch system uses for fluid
  • 14mm boxend wrench
  • Shop manual
  • Long flathead screwdriver
  • Pliers
  • Clear plastic tubing 3/8 OD x 1/4 ID (for bleeding the air from the line afterwards)
  • Catch can for the brake fluid you bleed out
  • CLEAN rags (important, make sure they are clean.
  • 1 or 2 friends to help bleeding the air out of the system (I did it by myself but it took a lot longer)
  • 12mm socket and ratchet
fcu-clutch02.jpg (22091 bytes)

Look at the clutch line section in the shop manual and notice where there is a FCU in the middle of the hydraulic line. The line bends around in a circle. This is what you are going to take out.

Pop your hood and get a visual on this little sucker. It will be bolted to the front passenger side of your transaxle and have a rubber hose and a steel line going into the top of it. These lines are just like the brake lines on your car so, once you think you have found the FCU make sure and follow the lines down to the clutch on the bottom of the transaxle. For those of you who have large hands like me, you might want to remove the large air hose that goes from your MAS to the turbo (this will make the job easier but it is not necessary). The FCU itself is about 4"-5" tall and 3" wide and is on a bracket that is bolted to the front of the transaxle.

fcu-clutch01.jpg (13771 bytes) Get out that 10mm LINE wrench. (Do not try this with a 10mm boxend wrench as you WILL strip the nut)  Loosen the line that comes up from your clutch (not the clutch pedal, but the clutch itself) and goes to the top of the FCU.

Jack up the car (using standard safety practices, braces, etc.) and get under it. Loosen the nut on the line that goes into the rubber line which is mounted on the FCU bracket.

The rubber line that goes into your FCU has a clip that holds it in place, this clip is on the underside of the bracket. Remove this clip with the pliers and the long screwdriver.

Completely unscrew both of the lines. Do not worry about air getting into the system, as you will bleed that out later. Just make sure that no dirt gets in at all. One little grit can still be dangerous to any hydraulic system.

Unbolt the four 12mm bolts that hold the FCU to the transaxle, and remove the FCU. Put this in a plastic zip-lock bag or something because it is full of brake fluid and will make an awful mess otherwise.

Now, the object is to connect the line that comes up from your clutch and went to the FCU, to the rubber line that went into the FCU, just without the FCU in between. This will take some VERY CAREFUL bending of the steel line to mate it up with the rubber line.

Double check to make sure that there is no dirt or contaminates on the flare, the flare seat, the male threads or the female threads. Connect the two lines, using your 10mm line wrench and the 14mm boxend wrench. Check your manual for the proper torque spec. (good 'n snug is what I used)

fcu-clutch03.jpg (24144 bytes)
This is the piece of steel tubing that you will have left over when you are done. fcu-clutch04.jpg (10142 bytes)

Bleeding the Clutch System

Time to get ready to bleed the system. The bleeder is on the bottom of the transaxle, right where the line goes into the cylinder. Loosen the bleeder with your 10mm line wrench just a bit and leave it on the bleeder. You now want to push the clear tubing on to the bleeder and run the tubing into the catch can.The reason the tubing has to be clear is to be able to see the fluid/air coming out when your bleeding the system.

Time to bleed the system. First thing that I did was to take a CLEAN paper towel and carefully stuff it into the hydraulic fluid (DOT 4 brake fluid) reservoir. This is the small reservoir about the size of a silver dollar. This is done to clean out the old and dirty fluid.

Fill it back up. Station one of your friends at this reservoir and have them keep it full. (Carefully! This stuff takes off paint!) Next, station one of your friends in your driver's seat. Their job is to slowly push in the clutch. Now, your job is to turn the bleeder after the clutch man pushes the clutch pedal to the floor. Then, tighten it back up, and then have the clutch man pull the pedal back up. (Remember that it is the clutch arm fork that pushes the clutch peddle back up so when you are bleeding the system, it is normal to have to pull the pedal back up off of the floor).

At this point the refill guy should be refilling. Do this a bunch of times. You will see a big pocket of air go through the system and after that happens you should do it a couple more times just to make sure.

Check for leaks.

You will know your system is bled correctly when you can put the car in gear, push in the clutch, and with the car jacked up, turn the tire by hand. If you have AWD you will, of course have to do some additional jacking at this point. If you can not, then you need to do some more system bleeding.

Test drive your "NEW" clutch.

I did this whole process by myself. The only difference is that it took a bit longer. What I did to push the clutch in is I got a 2 x 4 about 2'-3' long and pushed the clutch in with that and slid the seat up to hold it in place.

After I did this mod, I really noticed a big difference in the reaction time of the clutch during a shift. This WILL NOT fix a slipping clutch! It will simply allow it to engage a lot faster. My 16G stage III, ported everything, 2.5" DP and Cat, 3" cat back, FIPK, Fuel pump, Upper IC, BOV, 18PSI and some other stuff that I probably forgot 2G FWD would not scratch third gear shifts, and now it is soooo easy. Speed shifts into fourth used to be so bad that I could actually see the clutch dust in the review mirror. Not any more. The only drawback is that now your drive line, not your clutch, will be taking the abuse you intended for it in the first place.

Also, I can actually feel what the clutch is doing now. A little less refined, but a lot more defined.

Thanks very much to Rudy Vee and Mike Stella for their contributions to this VFAQ - And to Club DSM Canada for hosting it!