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Discussion Starter #1
Hey there

I had my mechanic swap my clutch fluid because it was gunky and had clearly a lot of water in it, but was working fine apart from that.
I usually drain the fluids myself by pumping - but i thought I would be reasonable to do it with shop tools to get most of the gunk out by pressure-changing.

Anyways, the clutch is now not working anymore as it should, it behaves like it has air in it. We swapped the hole fluid like twice and there were no bubbles coming out. There is no leak either, everything is dry, reservoir remains level.

Symptoms are that I have to sometimes pump the clutch so I can fully open it and change gear safely.

Any ideas where I could be looking further?

Thanks a lot
Alessandro
 

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What model Alfa?

The slave cylinder of a Spider (and I assume other models) can rotate in the mounting boss. To fully bleed the hydraulic system it must be positioned with the bleed screw uppermost. I would hope a mechanic would realize this but you know for sure...

If you can safely get under the car, have your trusted assistant operate the clutch pedal so you can measure the amount of travel. If significantly less than specified further investigation is needed.

Some Alfas have an adjustable pushrod at the master cylinder. But they are not meant to be adjusted in use. Rather it is adjusted on assembly then left alone. An unknowing mechanic might thus fiddle with the pushrod. Shown below is the Series 3 Spider's pushrod specification.
 

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The bleed nipple must be at the highest point of the slave cylinder to get all of the air out. I simply let some fluid run out by gravity without pumping the pedal. There is also a possibility that you have an air bubble where the hydraulic line connects to the master cylinder. Have your assistant press the pedal half way down and crack the fitting to let out a small amount of fluid and then tighten it again before the pedal is lifted.
 

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Richard Jemison
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Clutch

Well it probably does have air in it.

With someone holding the clutch petal fully in you need to bleed the line at the clutch master cyl.

Wrap it with cloth to keep the brake fluid off various surfaces, then crack the connection enough to get leakage at the fitting. You should hear air escape as well.

Close the connection before releasing the petal, and pump the petal and do it again.

Your problem is common. I hope the fluid used was DOT 3. Avoid newer blends that will attack older rubber compounds in the cars. That includes brake sys as well.
 

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Change the hose as well. ~$80.00 in parts. Bleed it from the bottom, much easier.
 

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Discussion Starter #6
So: round 2.

Tried bleeding at the Master as per RJs advice and also at the slave - some tiny bubbles came out but they could've also been sucked in when i cracked the return line open, so not sure.
I turned the slave so that the bleeder valve it up top.

I didn't notice a single change to the clutch - it is as dead as it was before.

The slave looks like it has been changed at some point, the master looks original. Both seem in OK shape - and again no leaks, no nothing... :-/

An ideas further ideas?

If no. Is there a way to determine whether the master or the slave could be at fault?

Btw I bleed many brakes, and renewed my lines when converted to brembos - no problems there, is there something special about clutches?

Thanks a lot!
Alessandro
 

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Symptoms are that I have to sometimes pump the clutch so I can fully open it and change gear safely.
The slave looks like it has been changed at some point, the master looks original.
Is there a way to determine whether the master or the slave could be at fault?
If you are confident that the system is now properly bled, then I would suspect the clutch master. The facts that the master looks old and that pumping the pedal will get the clutch to release, do suggest that the master may be the problem.
 

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I agree with Jay. Another way to test - if you push the clutch pedal down quickly does it work better? And if you slowly push the pedal down it doesn't work properly? Quickly pushing the pedal down tends to trap fluid behind the seals and will mask leaky, worn seals. Slowly pushing the pedal down tends to allow fluid to pass around worn, leaky seals.
 

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Discussion Starter #9
I only noticed now that whenever i depress the clutch quickly the fluid starts spilling out of the reservoir, as far as I know this should't happen. Am I assuming correct that there should be a seal protecting from this backlash (in the master)?

Thanks a lot
Alessandro
 

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The seals are cup shaped. When the pedal is pushed down the pedal's pushrod moves the master cylinder piston with the cup shaped seal down the fluid filled bore of the master cylinder. When the cup shaped seal is worn out the edges don't make good contact with the bore and fluid (now under pressure as you push the pedal down) leaks around the seal. That is why you get fluid erupting into the reservoir.

Time for a new or rebuilt master cylinder. If the rest of the system is of unknown vintage then I suggest changing the slave cylinder and flex hose at the same time. Inspect the metal line - if it is in good shape (no rust or kinks) then that can usually be re-used.

P.S. brake fluid will adversely affect paint - wash off any spills ASAP. I keep a spray bottle of soapy water handy (and old Windex bottle works well). Don't get any water in the reservoir - be sure the cap is in place before spraying the soapy water.
 

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I suggest you also replace the hose. They can look OK on the outside but fail internally. They can swell and slow/block the flow of fluid. Or a flap of rubber can come loose inside and act like a one-way valve.

Once & done!
 
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