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Discussion Starter · #1 ·
On my old T16 I had done quite a bit of clutch work. I rebuilt the master and slave cylinders and fitted a new pressure plate, friction disc and release bearing. Unfortunately the rebuilt slave cylinder burst a seal as soon as the clutch pedal was pressed and the brand new replacement leaked.

Well the clutch system worked okay for almost one year, but gremlins again returned to give me grief. I'd known for a while that the slave cylinder was leaking and the rebuilt master cylinder also started going.

I would loose the clutch pedal when manoeuvring (master cylinder) and there would be a small puddle of fluid underneath the car when left overnight (slave cylinder). The fluid level in the reservoir also dropped.

For several months I topped up the reservoir as at the time I had no facilities to do the replacement. However, inevitably something else happened to finally spell death for the clutch assembly.

Hydraulic fluid leaking through the front of the slave cylinder contaminated the grease in the release bearing leading to premature failure. I could hear and feel the dry bearing through the clutch pedal.

On the way home one day the release bearing finally gave up and I completely lost all clutch action. I was stuck in 4th gear yet somehow managed to get the car home without changing gear or stopping :nono; I strongly suspected that the release bearing had broken up completely.

In addition, fluid from the leaking slave had also contaminated the friction disc leading to intermittent slips and juddery take-up.

Well by then I had the garage kinda sorted out and was able to tackle the clutch job. Bear in mind that I expected to replace most components: master and slave cylinders, friction disc, release bearing and perhaps pressure plate too.

When I did the clutch job last time, I didn't remove the bonnet but this time I decided that I would. It's straightforward, and massively improves working at the front of the engine bay. Remember to remove the washer jet hoses first though!

I made up some protecting pads for the bonnet from old box packaging. I glued them together properly, but at that time tape'll did the job.




There's a channel here cut so that the bonnet edge rests securely:




Access to the clutch requires that all inlet to turbo piping be removed. This is how the engine bay looks before starting.


Air filter, air mass meter, AMM --> turbo inlet and turbo outlet --> intercooler all have to be removed, along with the EGR pipe. There are vac hoses to the APC solenoid and BOV that should be removed; I put these somewhere fairly obvious so that I don't forget to put them back!


...the engine bay looks like this:


Here you can see the plastic spawn-of-Satan clutch cover:


The clutch cover is held in place with three bolts. There is also a bracket for the bottom radiator hose that attaches to the front-left side of the clutch cover and into the gearbox. That bolt must be removed also.

I found it necessary to also remove the EGR pipe in order to get the clutch cover off.

Getting the cover out is tricky and involves wiggling it around. It's quite robust though and seems to tolerate the twisting needed. The job would probably be made easier if the clutch pipe is removed first.


The pressure plate, flywheel and slave cylinder are revealed. Something here don't look right to me:


You can clearly see that the release bearing is badly off-line and the bellows dust seal is damaged.




The proper Saab tool used for compressing the clutch. The tool is used when disengagnig the clutch using the pedal is not possible. The ring you see on the groud fits around the release bearing and then into the tool's fork. There is a lever on the tool's handle that hooks onto the pressure plate. The clutch can then be levered into a compressed state.


The fork end of the lever, and the ring that fits around the release bearing:




The ring opens up to fit around the release bearing (or whatever's left of it) and then closes into a circle. The fork-end of the lever then engages with the ring and with the hook on the pressure plate the clutch can be compressed.

To get the lever's ring in place, I found it necessary to cut away the rubber bellows around the dust cover. I'd hoped to re-use the bellows seal, but it was too badly damaged, plus I discovered a spare in the garage :)


These are spacer rings used to keep the pressure plate in compressed state so that it can be removed. There is a large ring and a small ring. The smaller ring is used on earlier pressure plates with shorter compression fingers:


As the spacer is sprung steel, it will hold itself in place on the pressure plate's inner ring while it's being compressed. When the clutch compresses, use a screwdriver to nudge the spacer into place. If the spacer isn't fully seated then it could pop out.

This is the primary chain cover. Behind that are the chains which link crankshaft drive (via clutch) to the gearbox. Also inside there is the clutch input shaft which must be withdrawn before the clutch parts can be removed.


At the front of the primary chain cover is a rod spring. Push in one end of this rod to unhook it from the drive cover. There's a circular cover that fits onto the front of the housing which you can pull away easily.

You'll then see a cross-shaped plastic part. This is an oil sprayer that lubricates the primary chains. It screws into the clutch input shaft and can easily be removed.

Circular cover and oil sprayer:


Time to withdraw the clutch input shaft. Screw a bolt into the end of the shaft and lever it back using the Saab tool or a pry bar. The shaft is held in place with a spring clip and will release suddenly and can damage the radiator unless care is taken (put thick cardboard behind the rad). The shaft cannot be fully withdrawn but it doesn't need to be for clutch removal.


You can see that the genuine Saab clutch tool has a cutout that fits around the bolt for levering out the input shaft:


With the input shaft withdrawn and clutch cover off it's time to remove the slave cylinder. I decided to clamp the flexible clutch hose to minimise fluid loss during removal.

The cylinder is held in place with hex socket bolts and they are a nuisance to remove with an Allen key because the dust seal gets in the way. In the past I had replaced the hex socket bolts with hex head bolts and removal is now no longer a problem. A ratchet spanner is a godsend for removing the bolts.

If the slave cylinder's piston is pushed in when the clutch pipe's out then hydraulic fluid will be ejected at speed onto the paintwork. To prevent that, tightly screw a spare cylinder nipple into the cylinder.


The pressure plate fits onto dowels in the flywheel and is held in place with six bolts. You will need to turn the engine over to get to all the bolts so make sure the gearbox is in neutral.

The pressure plate may need to be gently prised away from the flywheel with a screwdriver/pry bar. When it falls off the flywheel, you'll be able to wiggle the slave cylinder out and then lift away the rest.

If you plan on reusing the pressure plate or friction disc, then ensure that neither is contaminated with grease.

With the slave cylinder, pressure plate and mangled release bearing removed, here's how it looks:




The back of the primary drive case. This is where the slave cylinder fits (note the location of the bolt holes). You can see the hole where the input shaft emerges to engage with the friction disc and flywheel.


The slave cylinder and ruined release bearing/cover on the bench:
 

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Discussion Starter · #2 ·
This is one half of the release bearing. It should be a single unit, but heat and lack of lubrication have caused chronic failure and the two halves have separated. When the release bearing broke up, hardened pressure plate steel fingers carved into the bearing's metal shell:


What looks like a blob of goo on the left of is in fact solidified molten metal :eek:


Roughly in the centre of the photo you can see a metal disc. This is the other half of the release bearing. I still haven't found the bearings themselves :eek:


See what metal failure + 5000RPM does to a clutch assembly:






The pressure plate. All looks fine, until...


...you see two marks that look like clutch slippage:




The pressure plate fingers that hacked and ground up the release bearing and dust seal:


Friction disc. Despite the disc looking okay, I know it's junk because the friction material's absorbed hydraulic fluid and the clutch judders on take-up. Note the splined centre hole that mate upto splines on the input shaft.


There's barely any wear:


I had to wait for a replacement slave cylinder from the suppliers and so could not immediately replace the slave and related clutch components.

I did however have a new master cylinder to fit to the car and so was able to do that job. The master cylinder bolts from the engine bay onto the front of the bulkhead with nuts inside the cabin. The hydraulic are of course in the engine bay. So to remove the master cylinder requires access from both engine bay and cabin.

First the kick panel must be removed, to give access to the cylinder's bolts and linkage to the clutch pedal. There is a bolt in the centre of the kick panel that's visible after the centre console's been removed:


You'll also have to remove the cover underneath the steering wheel (two bolts and one plastic clip).

There are also two bolts inside the engine bay, inside each front wing. The right-hand bolt's in here:


Close up showing bolt in centre of photo:


Left-hand bolt:


Close up showing bolt in centre of photo:


With those three bolts removed, the kick panel can be released.




You can see the general master cylinder arrangement at the back of the bulkhead:


Fluid can clearly be seen leaking from the back of the master cylinder. This then was not only leaking fluid past the internal seals (giving loss of pedal during manoeuvring) but also past the front seal. Note the studs and nuts that secure the cylinder to the bulkhead.




Poor picture - clevis pin arrangement. The brass clip pulls radially away from the pin which can then be pulled out of the joint.


Note the molybdenum grease used to lubricate the clevis pin:


Inside the engine bay, you can see the fluid supply pipe from the reservoir to the master cylinder:






Clamp and pull off this supply hose. Then unscrew the high-pressure pipe from the front of the cylinder. Removal of the pipe is made easier if you undo the clamp:


From inside the cabin, remove the two nylok nuts that secure the master cylinder to the bulkhead.

Master cylinder removed:


Old master cylinder removed from car. You can see the barbed pipe from the top of the unit; that is for the fluid feed.


New unit. I wondered why a new gasket isn't supplied with the new cylinder. Neither do you get new nylok nuts!




New and old:


New unit bolted to the bulkhead, and clevis pin inserted and greased up:


View from the engine bay:


The new clutch pressure plate has to be compressed prior to fitting. In the uncompressed state, the protruding pressure plate springs mean that there's insufficient clearance to drop the whole clutch assembly into place.

I've seen several approaches to compressing a pressure plate and I dislike all of them. Using a lever to compress the clutch was the obvious method. I use two planks of wood, a roll of insulation tape and a block of wood.

Put the pressure plate on the first plank to protect it from debris and damage, and also to raise it off the ground slightly. Then place your chosen spacer tool around the edge of the pressure plate springs. I use the genuine tool because it's spring loaded and will pop into place when the clutch is compressed.




The roll of tape is used as a spacer between block of wood and springs. Without it the block of wood we'll use would end up flush with the pressure plate's top surface before the clutch had been fully compressed.


Next the block of wood balancing on the tape roll.


You need a pivot for the lever. I used the front doorstep of my house. Notice the continuity error later on in the photos where the plank's been moved. This is because the doorstep started to lift :eek: Make sure that whatever you use as a pivot is solid because you'll be exerting a lot of force against it.

I used a plank from an old pallet, but this wasn't really strong enough and started to splinter just as the clutch compressed. I used to have a length of hardwood decking, and that was excellent. Ideally the lever should be very strong and inflexible.

Push the plank downwards until the springs pop downwards. If you do use a plank, you'll be able to sit on one end freeing up both hands to poke the spacer into place. You must fully compress the plate and get the spacer right underneath the edges otherwise the huge force of the springs will push the spacer out at great speed. Not nice when it happens as you're leaning over the engine bay :eek:


Here you can see the compressed pressure plate with the spacer securely in place. This is how yours should look.




With that done, it's time to grab a cuppa and then inspect the slave cylinder components. Here we have (left-to-right) the slave cylinder, rubber dust bellows and the release bearing. The amber coloured goop on the end of the slave cylinder is to protect the end of the slave from damage and should be removed prior to fitting. The release bearing comes pre-greased and further grease should not be added.




Rubber bellows and release bearing stacked up on top of the slave cylinder. This is how those three components fit together when they're installed.


See the gap between the end of the slave cylinder and the top of the release bearing? Well the whole assembly has to be compressed to take up all that space so that the assembly will fit. The spring inside the rubber bellows allows us to do that.
 

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Discussion Starter · #3 ·
The method I use for this is to stack up the friction disc, pressure plate, slave cylinder, bellows and release bearing. Then thread strong cable ties between the friction disc's holes up through the pressure plate springs and loop around the slave cylinder's bolt holes. That allows you to tighten the cable ties and compress the whole assembly. You then have just one component to lower into place leaving one hand free.


Don't forget to add a dab of molybdenum grease to each spring finger where there'll be contact with the release bearing.


If you look carefully you'll see that that there's no friction disc in this photo. That's what happens when I try to rush a job.


Tighten the cable ties evenly until there's no more slack. A word of warning here: be careful where you thread the cable ties on the plate, as if you can't unthread them after the whole assembly's bolted up then you'll have to remove it all again. The ties can easily bind on the sharp edges of the friction disc and pressure plate.


Here we see the whole assembly lowered into position with the pressure plate loosely bolted to the flywheel. I recommend that you use just three bolts on the pressure plate until after you've removed the cable ties and ensured that everything's in order. Fewer bolts to remove if there's a cockup :p


Note that the slave cylinder's isn't correctly orientated: it needs to rotate clockwise by around 90°. It's out of whack because I rotated the flywheel when inserting the pressure plate bolts.


If eveything's okay, then insert the remaining bolts and hand tighten. Then torque up the bolts to the correct spec (can't remember what this is - check Bentley/Haynes). Tighten diagonally opposite bolts, then move around one and repeat.

This is the bolt that I screw into the end of the clutch input shaft when it's removed. It's also a useful extension when the bolt needs to be pushed in upon reassembly. I lever the bolt against the front engine mount.

Don't use brute force on the input shaft. If the splines on the shaft don't line up with the friction disc then you'll get nowhere. The shaft should fully engage with a click. If you can push the shaft in only part of the way, apply gentle pressure on the lever and rotate the flywheel a little. You should then feel the input shaft engage with the flywheel.


Everything's bolted up here but the spacer is still held within the pressure plate and that must be removed. I once used the clutch mechanism itself to depress the plate and allow removal of the spacer but I am fairly sure that hyperextension of the slave cylinder piston damaged its o-ring seals. The result was an instantly knackered slave.

My solution was to use the Saab clutch compression tool entirely for removing the spacer. The information following about using the tool is of course relevant to getting the clutch out in the first place when the slave cylinder has failed.

Here is the compression tool's collar that fits around the release bearing. Notice how it's hinged at the top.


The collar's in place now.






The prongs on the end of the lever have cutouts which match spigots on the collar.


The next sequence of photos show how the lever hooks onto the pressure plate, and how the prongs fit into the collar.








Pulling back on the lever exerts a force against the collar which depresses the pressure plate's springs.This frees up the spacer. Pull back on the lever with one hand and pull out the spacer with the other. Spacer gone now!




You now have a choice: put everything back and then bleed, or bleed and then stick everything back. It's probably wise to bleed first, as if there's a problem with the slave you then don't have to remove everything again in order to inspect it.

So, refit the clutch pipe to the slave. Make sure to use a proper brake pipe spanner as an open-ended type isn't strong enough and could round off the fitting - then you're knackered!

Time to bleed the clutch system. I used a simple setup with a spare plastic container as a reservoir for the old fluid. Take one bottle and a length of spare vac hose. Drill a suitably sized hole in the bottle's cap and push through the hose until it's towards the bottle of the bottle. The hole should ideally be undersized so that the hose fits tightly.




This is the Gunson Eezi-Bleed kit that everyone seems to resist buying. It does the job but is messy. I used to recommend it until I bought a Mity-Vac which really is the best and easiestway to bleed hydraulic systems. At least the Eezi-Bleed's inexpensive.


Fill the Gunson bottle with fresh brake fluid and screw the cap that's on the end of the clear plastic hose screws onto the car's reservoir. The black hose fits onto the valve of the spare tyre. Make sure there's no more than 20PSI pressure in the tyre, otherwise the Gunson bottle might spray nasty paint-stripping brake fluid over your car's bodywork.


The idea is to use air pressure from the spare tyre to force new fluid from the Gunson bottle through the clutch circuit and out, draining into a spare container taking with it all the air and old fluid.

Connect the hose from the spare container you're going to use and fit it over the bleed nipple on the slave cylinder. Make sure the bottle's not likely to fall over and that it doesn't overflow.

Put the bleed kit's connector on the spare tyre valve and then open the bleed nipple to allow fluid out. Watch carefully the level of fluid in the Gunson bottle. When it gets towards the minimum mark, close off the bleed nipple, disconnect the tyre and refil the bottle. It's wise also to empty the drain bottle into something larger.

I had to chuck around a litre of fluid through the clutch circuit before I had any pressure in the pedal. I'd strongly recommend you push through two litres before you try the pedal. If you jump on the pedal when there's no pressure in it, then you could damage the seals.

After bleeding, try the pedal gently. If there's no pressure by the time the pedal's halfway down then don't push it any further. Instead push more fluid
through the system. Only depress the pedal fully when you have pressure.

I hear that pumping the pedal while the Eezi-Bleed pushing fluid through the circuit is the mot effective way to bleed the clutch. Never tried it myself but I've seen it done with excellent results.

Here's the engine bay with everything back to where it was. It's easy to nudge off the spade terminal that connects to the water temperature sensor (close to the thermostat housing). If you find that the temperature gauge on your car doesn't work after doing the clutch job, then that'll be the reason.


When I removed the existing clutch I discovered a crack in the friction disc. This Borg and Beck/AP clutch had less than 10,000 miles on it and I shall be returning it to the supplier for a refund (along with the faulty slave cylinder).




I am (very) happy to report that there was no sign of leaking fluid from either master or slave, the reservoir remained at the same level and the clutch action was excellent with no loss of pedal during manoeuvres.
 
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