22.01.2006: Saab NG900 Hydraulic Clutch Conversion

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22.01.2006: Saab NG900 Hydraulic Clutch Conversion

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Hydraulic clutch conversion on a 1996 Saab 900. The troublesome cable clutch on a 1994-1997 Saab 900 can be relatively easily converted to hydraulic. In 1999, Saab issued a detailed upgrade document describing the conversion, but in essense it's just a direct swap to newer parts used in the NG900/9-3 family from 1998 on. You can get a conversion kit from online suppliers like genuinesaab.com, order the necessary parts from your Saab dealer, or just dig them up at the nearest scrap yard.

You need a clutch pedal with a master cylinder, a clutch line to the gearbox, a brake fluid feed hose to the brake reservoir, and finally a slave cylinder that goes into the transmission replacing the old throwout bearing. The latter part requires a transmission removal, which is described in this section.

In my case, the parts came from a scrap yard, taken off a 1999 Saab 9-3. The slave cylinder installation is not covered here, since I was replacing the entire transmission, but it's fairly straightforward, and the slave bleeding procedure is described in the transmission installation section. After everything is installed, the new clutch system needs to be flushed using a pressure bleeder.

Tools:

13 mm socket: cluth pedal nuts;
13 mm wrench: upper nut on the clutch pedal;
10 mm socket: lower dash cover, fuse box, coolant tank;
Torx T25 screwdriver: lower dash cover, fuse panel;
metal cutting tool: e.g. a rotary tool with a flexible extention or a 90° attachment;
drill with a 3 mm and 9 mm metal drilling bits.

	22.01.2006 Lower dash Remove the lower dash cover -- half a dozen Torx T25 screws and one 10 mm bolt.		22.01.2006 Fuses Three more T25 screws to remove the fuse panel.
	22.01.2006 Clutch pedal Remove both lower and upper air vents to get a better access to the clutch pedal. Unplug the pedal position sensor.		22.01.2006 Upper bolt Slacken the upper nut on top of the clutch pedal: it's completely hidden from view, and you need a short wrench to get it moving. The nut to the right of it does not need to be unscrewed, but it might help to remove the pedal.
	22.01.2006 Fuse box Remove the plastic nut down below at the corner of the fuse box. Lift the rubber strip along the firewall and unhook the other corner. Lift the fuse box and move it aside as far as the wires allow.		22.01.2006 Clutch cable Undo two nuts holding the clutch pedal to the firewall. Inside the car, detach the clutch cable from the pedal, and remove the pedal completely. From the outside, pull the cable out of the firewall.
	22.01.2006 Cable and pedal The clutch cable and old pedal on the floor.		22.01.2006 New vs old The old clutch pedal is just a lever on a mounting bracket. The new one incorporates a hydraulic master cylinder.
	22.01.2006 New vs old The master cylinder goes through the firewall in a location different from the cable.		22.01.2006 New vs old One of the mounting bolts for the new pedal is also in a different spot.
	22.01.2006 Drilling template This is a drilling template from the Saab manual. The upper circle is 17 mm, while the lower is 35 mm. The mounting hole in the right is 9 mm.		22.01.2006 Two templates I made a second copy of the template to get a clear picture of the cut-out usage.
	22.01.2006 Sticky tape The round holes are to be combined into an oval. The double-sided sticky tape will be used to attach the template to the firewall.		22.01.2006 Applied Attach the template making sure it fits the existing holes. Mark the outside shape and peel it off.
	22.01.2006 Rubber cut Cut and remove the rubber insulation on the firewall.		22.01.2006 Marking a hole Now that you've reached the metal, apply the template again and mark the oval and the mounting hole.
	22.01.2006 Cutter Get a proper metal cutter. A rotary tool with a flexible extention or a 90° adapter should work fine. Eye protection is a must.		22.01.2006 Hole Half a dozen cutting discs later, and the oval is finished. The mounting hole in the right is easy -- just start it with a thin drill bit (e.g. 3 mm), and then do a second pass with a 9 mm.
	22.01.2006 Primed Sand and prime the cut-out to protect it from rust. Do the same on the outer side of the firewall.		22.01.2006 Painted Paint the surface. One of the old mounting holes is not needed anymore, plug it with a short bolt and tighten the nut on the other side. Plug the old cable hole too.
	22.01.2006 New pedal When fitting the new pedal, place a 2 mm washer under the bolt that goes into the newly drilled mounting hole. Fit the upper mounting bracket and tighten the nuts.		22.01.2006 Master cylinder Tighten the nuts on the outside of the firewall.
	22.01.2006 Brake reservoir Cut the end of the downward pointing nipple on the brake reservoir, about 3 mm should be enough. Catch the brake fluid that will leak out.		22.01.2006 Hose Attach a hose to the nipple and clamp it tight.
	22.01.2006 Hose Attach the other end of the hose to the upper socket on the master cylinder. Clamp it as well.		22.01.2006 Sensor Fit the air vents and attach the clutch pedal position sensor.
	22.01.2006 Fuses Install the fuse panel.		22.01.2006 Lower dash Put the lower dash cover back on. It's amusing how much the new pedal stands out.
	22.01.2006 Coolant tank Remove the nut holding the coolant expansion tank. Lift the tank.		22.01.2006 Hole Drill a hole on the edge of the side member for a clamp that will hold the clutch line.
	22.01.2006 Clutch line A new clutch line. The rubber section is there to accomodate the engine movement. The 90° bend on the right is where the line will be clamped.		22.01.2006 Clamp Route the clutch line between the fender and the ABS unit bracket and secure it with a clamp.
	22.01.2006 Master Plug the end of the clutch line into the master cylinder and insert the locking clip.		22.01.2006 Clutch line The other end of the clutch line will be attached to the slave cylinder once the transmission is installed.

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