Clutch Slave Cylinder Replacement Guide ? Anyone..
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Shiz
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Previously stated that my brake hydraulic light was showing, released at the early stages of having the car that the rubber boot around the cylinder by the pedal was leaking. I ignored this at the time, and only realised last night that there was no fluid at all in the clutch reservoir. The small reservior looks fine, therefore I pressume its the small slave cylinder leaking. Are these hard to change ?.. Could anyone give me a brief run down. Any help would be appreciated. Thanks
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daimlerman
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Is your car LHD?
Youth is wasted on the young.
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andyp
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no they are not hard to change at all, you will need a very long 3/8 drive extesion bar plus a normal and a short one all together and you will be able to get to the nuts on the cylinder to undo it
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Brianmoooore
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In that case the level of the clutch fluid is not connected in any way with any warning lights that may have appeared on the dash.Shiz wrote:No RHD.. UK spec.
The clutch fluid could also be leaking from the master cylinder, or from the hose where it connects to the master cylinder. In both these case, fluid will have run down behind the carpet.
If you do change a hydraulic cylinder, it's strongly recommended that you change both the master and slave at the same time, since it's very likely the other will fail a few weeks later if left.
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milescook
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Go on then. It's half 3 and I have a crap case of food poisoning so not really getting much sleep.... 
Subject to ammendments from the experts, and I do mean people that have been mechanicing for more than 5 minutes as I have, see the below. Any comments are welcome as this is purely based on my experience and a few other top tips from the forum. Also, the article is intending to be heading the way of the wiki, as promised a while back.
Just realised you actually want a guide for the master, but you'll have to do the slave as well probably, so here's my effort:
This article is written specifically for RHD models. The principal difference being there is a specific reservoir for the clutch fluid. (See image).
The clutch system works on the same principal as the brakes, and 2 cylinders and some hoses transmit the force from the pedal, via clutch fluid (which is the same as brake fluid), to the slave cylinder and clutch release mechanism. The clutch slave cylinder is basically a small hydraulic ram with a piston on the end. When operated, the piston pushes the clutch release mechanism, or at least it used to before you had to read this artcle... This system must be airtight and have no leaks, and can be bled from the slave cylinder in the normal brake bleeding fashion.
Diagnosing a clutch fluid issue is simple. Your pedal goes soft, it becomes very difficult to impossible to change gear, and you may hve very little or no clutch fluid left. The two main culprits are the master clutch cylinder which sits behind your clutch pedal, and the slave cylinder which is bolted to the gear box. If you get clutch fluid around your pedals, then it's the master. If the slave cylinder fails, it leaks fluid into the bellhousing so there is no visible sign of leaks anywhere except for a drip from the bottom of the bellhousing (which most people assume is engine or gearbox oil).
It's recommended to change both master and slave when one fails. When your slave cylinder fails, the piston in your master cylinder would have travelled a little further than it has in the last twenty odd years, and this damages already fragile seals on the crud that has built up.
Firstly if you are taking the slave cylinder off you want as little fluid in the system as possible, otherwise it will just end up in your eyes. Next you remove the gearbox protective plate for easier access, which is attached by two screws to the front beam and two nuts further back. One of my front subframe screws couldn't be secured properly, so a cable tie through the beam holes sufficed. You will need to disconnect the slave cylinder via two nuts, one below one on top. The top nut requires an extension to reach which can get past the hose - see below.
Don't let the cylinder dangle on it's own - just like a brake caliper. To unattach those cylinder from the hose I found it easier to disconnect the hose from it's source, whch is a standard metal pipe with an 11mm union nut. These are notoriously prone to rounding off, and if they do you are pretty screwed, so lots of patience is required. Soak it in WD40 overnight if possible, apply lots of heat if you can (heat guns are brilliant and cheap), and use a proper flared spanner. Google them, and you'll see they wrap around the nut giving you less chance to round the nut. Using a standard spanner on the hose end and flared spanner the other side on the brake pipe nut, give the front spanner a few shock whacks to loosen the nut, and all being well you'll shortly wonder what all the fuss was about. After 20 odd years these unions are so siezed to the hose, and are likely to be as soft as cheese.
With the hose and cylinder off, it's easier to take the hose off the cylinder using the method above in your hand or a vice, rather than underneath the car on your back. See the below picture which tells you all you need to know about getting these unions off! I know the hammer is in shot, don't go nuts with it, it's just to give the spanner a few hard short shocks to un-seize the union, then it should come off by the normal means. When you put the unon back on the new cylinder, do the next chap in 20 years a favour by spraying the thread (not inside) with copper grease.
Re-attach the hose back to the car, and either re-attach the cylinder first then bleed the system (as I did), or bleed first which some people prefer. The bleed valve is on the slave cylinder and on mine is a 7mm nut. Bleeding will be covered in detail elsewhere, but I used a £5 one way valve hose from Halfords that went into the brake fluid bottle on the floor, kept topping up the reservoir and pumping the pedal, until eventually (when I realised how to correctly use the hose...) I saw no bubbles in the fluid. Handily you can pump the pedal by hand reaching into the cockpit whilst on the floor looking underneath the car at the tubing. When finished,
remember to top up the reservoir fully.
The pedal stays soft at this stage. The moment of truth is when you tighten the bleed valve, pump the pedal once, then on the second press it should go hard. To test, I lowered the car off the front jackstands, moved everything out the way of the front of the car, fired up clutch down put in 1st gear to see no revs drop or car movement. Then did a clutch bite point check, went through all the gears, a short test drive, and rewarded myself with a plate of chips.
(Pictures from milescook unless specified, some text provided / ripped off from users Brianmooooooore and willnz).
Subject to ammendments from the experts, and I do mean people that have been mechanicing for more than 5 minutes as I have, see the below. Any comments are welcome as this is purely based on my experience and a few other top tips from the forum. Also, the article is intending to be heading the way of the wiki, as promised a while back.
Just realised you actually want a guide for the master, but you'll have to do the slave as well probably, so here's my effort:
This article is written specifically for RHD models. The principal difference being there is a specific reservoir for the clutch fluid. (See image).
The clutch system works on the same principal as the brakes, and 2 cylinders and some hoses transmit the force from the pedal, via clutch fluid (which is the same as brake fluid), to the slave cylinder and clutch release mechanism. The clutch slave cylinder is basically a small hydraulic ram with a piston on the end. When operated, the piston pushes the clutch release mechanism, or at least it used to before you had to read this artcle... This system must be airtight and have no leaks, and can be bled from the slave cylinder in the normal brake bleeding fashion.
Diagnosing a clutch fluid issue is simple. Your pedal goes soft, it becomes very difficult to impossible to change gear, and you may hve very little or no clutch fluid left. The two main culprits are the master clutch cylinder which sits behind your clutch pedal, and the slave cylinder which is bolted to the gear box. If you get clutch fluid around your pedals, then it's the master. If the slave cylinder fails, it leaks fluid into the bellhousing so there is no visible sign of leaks anywhere except for a drip from the bottom of the bellhousing (which most people assume is engine or gearbox oil).
It's recommended to change both master and slave when one fails. When your slave cylinder fails, the piston in your master cylinder would have travelled a little further than it has in the last twenty odd years, and this damages already fragile seals on the crud that has built up.
Firstly if you are taking the slave cylinder off you want as little fluid in the system as possible, otherwise it will just end up in your eyes. Next you remove the gearbox protective plate for easier access, which is attached by two screws to the front beam and two nuts further back. One of my front subframe screws couldn't be secured properly, so a cable tie through the beam holes sufficed. You will need to disconnect the slave cylinder via two nuts, one below one on top. The top nut requires an extension to reach which can get past the hose - see below.
Don't let the cylinder dangle on it's own - just like a brake caliper. To unattach those cylinder from the hose I found it easier to disconnect the hose from it's source, whch is a standard metal pipe with an 11mm union nut. These are notoriously prone to rounding off, and if they do you are pretty screwed, so lots of patience is required. Soak it in WD40 overnight if possible, apply lots of heat if you can (heat guns are brilliant and cheap), and use a proper flared spanner. Google them, and you'll see they wrap around the nut giving you less chance to round the nut. Using a standard spanner on the hose end and flared spanner the other side on the brake pipe nut, give the front spanner a few shock whacks to loosen the nut, and all being well you'll shortly wonder what all the fuss was about. After 20 odd years these unions are so siezed to the hose, and are likely to be as soft as cheese.
With the hose and cylinder off, it's easier to take the hose off the cylinder using the method above in your hand or a vice, rather than underneath the car on your back. See the below picture which tells you all you need to know about getting these unions off! I know the hammer is in shot, don't go nuts with it, it's just to give the spanner a few hard short shocks to un-seize the union, then it should come off by the normal means. When you put the unon back on the new cylinder, do the next chap in 20 years a favour by spraying the thread (not inside) with copper grease.
Re-attach the hose back to the car, and either re-attach the cylinder first then bleed the system (as I did), or bleed first which some people prefer. The bleed valve is on the slave cylinder and on mine is a 7mm nut. Bleeding will be covered in detail elsewhere, but I used a £5 one way valve hose from Halfords that went into the brake fluid bottle on the floor, kept topping up the reservoir and pumping the pedal, until eventually (when I realised how to correctly use the hose...) I saw no bubbles in the fluid. Handily you can pump the pedal by hand reaching into the cockpit whilst on the floor looking underneath the car at the tubing. When finished,
remember to top up the reservoir fully.
The pedal stays soft at this stage. The moment of truth is when you tighten the bleed valve, pump the pedal once, then on the second press it should go hard. To test, I lowered the car off the front jackstands, moved everything out the way of the front of the car, fired up clutch down put in 1st gear to see no revs drop or car movement. Then did a clutch bite point check, went through all the gears, a short test drive, and rewarded myself with a plate of chips.
(Pictures from milescook unless specified, some text provided / ripped off from users Brianmooooooore and willnz).