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cchan
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Clutch Slave Replacement

Post by cchan »

I have some questions. We installed a new clutch Slave on the restoration of our Alfa. We have driven it around 700 miles since the restoration and the last trip we had an issue. The Clutch peddle hit the the floor, there was smoke from the back area, and the clutch grabbed higher and higher. It was a very hot day and we were stuck in 1 1/2 hours of traffic going uphill. We barely made it home. It seems that this problem might have resolved itself on this Own???

When this happened, we towed it to the warehouse and parked it and used my other Alfa for the rest of the summer events. Now that summer is over, we put the GTV6 on the lift and the clutch works fine. We inspected it and it apears that there are no leaks in the rubber hose and assume that the metal piping where the rubber hose connects is intact. There is no evidence that there is a leak with the exception of a little moisture on the rubber cap of the slave. I think this is where there might be a leak since it should have no moisture or brake fluid dirt.

This leads to my question, it this were the slave would leak? If so it is possible for it to fix itself? I think the part is not that expense so I was just thinking of installing a new one to insure that we don't get stuck in the street. I am posting some picture for your review and assistance. You can see the area in Slave #1 by the 12 stamp. It is slightly dirty with alittle stain at the seal. The confusing part is that it is working and the clutch engages. Thank you for any and all suggestions.
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Slave #1.jpg
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Slave #3.jpg
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Slave #5.jpg
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MR2 Zig
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Re: Clutch Slave Replacement

Post by MR2 Zig »

when the slave was bled did you rotate it so the bleed nipple was at the top? If not you may have had some air in there that expanded with the heat and your foot on the clutch pedal in traffic may not have allowed the relese of pressure and it caused the piston to go out of the slave to relieve the pressure. Given time to sit for a while the system settled back into a serviceable state. Is you clutch fluid resivoir lower than it had been?

hth,
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cchan
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Re: Clutch Slave Replacement

Post by cchan »

I did not personally bleed it. JJ did and then I think that Phil did when we had to replace the clutch. The brake fluid was lower and I know that fluid was released in the rear since I saw the smoke. There was also the usual burnt clutch smell as well.

Are you suggesting that we just rebleed the system and keep the current slave?
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Zamani
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Re: Clutch Slave Replacement

Post by Zamani »

Maybe you can try this, jack the rear of the car as high as possible. Fill up the brake fluid reservoir to the max, then open the bleed screw and let it slowly drip. I'm not sure if this will work 100%, but if you start bleeding by pumping the pedal, I think smaller bubbles form and may not go out of the system. But by not agitating the system, the bubble will slowly and naturally work it's way to the bleed screw.

However you did mention about the smoke...was that brake fluid smoke or clutch smoke? COuld be that it is an old stock part. It may be worth replacing to avoid the risk of being stuck in traffic.

Also, please try to make it to the All Italian Day in Alameda next month.
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Re: Clutch Slave Replacement

Post by Typhoon90 »

I used to own a Valiant with a 4.3 litre six and really tall diff gears (2.92). A few times when I owned it, the clutch plates got hot and wouldn't really engage, it'd just slip. The fact it had really tall gears meant if you got stuck crawling up hills in heavy traffic, you'd have to do a fair bit of clutch slipping and the clutch friction point would slowly come higher and higher up on the pedal. The pedal would also go REALLY light, like it was disconnected. Yes, it would even get to the stage of not transmitting full power and slipping. When let cool for an hour, it would be just fine.
I mention all this because that clutch system was a completely mechanical linkage, no hydraulics involved at all.
I suspect your friction disc was overheating or something similar, if the car smelt like hot brakes when it was happening, I am sure of it.

Regards, Andrew.
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Re: Clutch Slave Replacement

Post by Bruce »

If the clutch slave was leaking (I have recent experience) the shared brake & clutch reservoir level would drop. My clutch pedal used to stick down and this was due to a defective clutch master cylinder caused by a clogged supply hose (right hand drive cars have a long rubber hose with collapses internally). Recently the clutch fork pivot broke and caused the pedal to stick down, which I pulled back up and ended up with a lower and shorter stroked clutch pedal.
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