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Discussion Starter #1
Glad I found this site! I recently rebuilt the engine and trans in my '79 Spider. All back together now (not quite ready to start, and nervous to do so after below), but I tried to bleed the clutch and *think* I'm having problems. I've got all the air out of the system, but the pedal is so soft, you can reach into the engine compartment and easily push in the lever with your fingers. I replaced the master and slave cylinders and hoses, but it does the same thing. I'm using Dot 3 fluid. No leaks, No air. The slave cylinder moves the clutch fork only about 3mm - the book says it should move 11-12mm. I'm really frustrated, having gone through 2 masters and 2 slaves with no luck. Is it only supposed to move this far? Any ideas? I'm not a novice at this stuff, and I don't *think* I'm missing the obvious. What gives? thanks!
 

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1. Are you SURE you have all the air out of the system? Did you bleed the slave cylinder with the nipple on top?

2. When you push the clutch pedal in by hand can you see the clutch master cylinder piston being pushed in?

2. Is the clutch pedal pin broken in the pedal pivots? see the following link. Look for the two entries under "clutch"

http://www.geocities.com/motorcity/downs/3837/features.html
 

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I also have a 79 spider. I replaced the slave cylinder and line a few years back. From what I remember it went pretty trouble free. The slave cylinder does move the clutch arm about a 10 mm to 15 mm. and it is very heavy under foot. It would be very hard to push in by hand. I'm no pro but it sounds like air in the lines or the pedal itself. Have you tried cracking the nipple and letting the line slowly drip over night. This is what I had to do once to get air out of my brake lines. It works good luck.
 

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Let me reinforce what has been said above. Be ABSOLUTELY sure that the bleed nipple is at 12 oclock when you bleed the clutch otherwise there will always be some air trapped in there.
 

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Discussion Starter #5
Thanks for the replies - I had not thought about keeping the bleed nipple at 12 o'clock. I'll give it a shot. IAP suggested that the rubber hose may have a "bubble" in it, where it's expanding. I don't see anything, but I'll replace it (again) too. Thanks!
 

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Before you start replacing anything, be sure to check the mechanical integrity of the pedal system. If you can easily push the pedal down with fingers, it sounds like you may have a clutch pedal pin or linkage broken. Visually check to ensure that the clutch master cylinder piston is indeed being pushed in all the way when you work the pedal.
 

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Discussion Starter #7
Thanks for everyone's help. The problem was the slave cylinder being bled at the bottom instead of the top. All the air's out, and the clutch now releases! Thanks!
 

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Excellent! Pretty soon we'll have a legitimate searchable database with genuinely usefull info!!
Long live AlfaBB.
 

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What to do when the clutch won't bleed

The Master Cylinder (MC) on my US-Spec (Spica) 69 1750 (and no doubt other similar cars) would not bleed. After bench testing, I realized that the distance between an open intake hole and closed is very small. If the mechanical adjustment to the MC presses at all on the intake hole it will not bleed. However, trying to work this out using the bleed valve on the slave cylinder (SC) is difficult because it is so far from the MC, especially if your car is on jack stands with not a whole lot of working room.

First, in the event that your clutch hydraulic pipes were removed, you need to know which is the intake (from the reservoir) and which is the outlet (to the SC). As can be seen on this photo, the bottom hole (#2), not the angled hole (#1), is the intake.



1.) Buy a new Clutch-Hydraulic-Flexi-Hose. Keep it clean because you are going to put it in your mouth.
2.) Install the MC but do not hook up the pipes.
3.) Screw the flexi hose into the intake hole (#2).
4.) Blow into the hole and determine that air is coming out of the outlet (#1)
5.) Begin adjusting the mechanical screw that increases or decreases the length of the clutch actuator rod (is that the correct name?) until the air stops flowing
6.) Back off so it flows again.
7.) Check the clutch pedal to make sure it is where it should be
8.) Carefully mark the threads on the adjustor to make sure it does not move. Lock it in.
9.) Install the pipes that go to the reservoir and SC, which may require removing the two MC bolts and dropping the MC (this is why you marked the thread adjustment)
10) Bolt everything back together (including your new flexi-hose) and begin normal bleeding

At that point, fluid should flow through the system. As others have said, make sure the SC bleed screw is at 12 o'clock (above the flexi hose). I found it was worthwhile buying a vacuum pump which is not very expensive, but makes the job a whole lot easier.

Below is a photo of how I did it, which is slightly different than what I recommend from hindsight. I cut an old flexihose in half so I could insert the bleed screw from the SC into it to test using vacuum. When that produced weird results (my adjustment was slightly off so vacuum made it work with the #1 & 2 pipes reversed but not when correctly installed), I finally pulled the MC apart to figure out how it works, which is when I realized there was slight pressure on the valve which was blocking flow from the reservoir. Obvious in hindsight, but maddening until I stopped thinking about the parts as black boxes and paid enough attention to work out the actual engineering.


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