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Low clutch pedal, massive confusion

4K views 21 replies 11 participants last post by  AlfaAL 
#1 ·
Finally got the 164's clutch M/C replaced, but the pedal is maybe 2 or 3 inches off the floor, and has to go all the way down to disengage. The mechanic – one of the brothers who run Alfa Italia in Burbank – just shrugged and said maybe it'll come back up after a while. Multiple pumps didn't seem to make any difference either. it seems odd to have no way to adjust pedal height in these things.

Adding to my confusion is the odd terminology employed in the manual. Every car I've had with a hydraulic clutch has a unit acted upon by the pedal linkage called a Master Cylinder, which then sends fluid under pressure to a Slave Cylinder, which operates the clutch. The 164 manual refers to the first device as the "pump" and the one at the clutch end as the Master Cylinder … and the part I had replaced was called the Master Cylinder. And I recall being told by a very good amateur mechanic I trust that the 164's master cylinder was under the dash … !
 
#2 · (Edited)
Hi Will. I've been there and the photos below show the cause. My pedal didn't break right away - in the early stages, the symptoms matched what you describe. Solution was to get a good, used pedal from APE.

And I recall being told by a very good amateur mechanic I trust that the 164's master cylinder was under the dash
Yup, it's all a bear to get at. Actually, I think replacing the pedal will be easier than replacing the clutch master.

The mechanic – one of the brothers who run Alfa Italia in Burbank – just shrugged and said maybe it'll come back up after a while.
Wow - that's kind of scary. If you ever need any brake work, have the other brother handle it!
 

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#3 ·
Most of us call the one under the dash the master and the one acting on the clutch arm the slave, no matter what the book says.
There is no adjustment that I'm aware of for the clutch pedal; however, sometimes the pedal arm fails up near the pivot point and the pedal goes closer to the floor before it fails completely.

That's it, Jay:)
 
#6 · (Edited)
Thanks, guys! Calling APE first thing tomorrow.
Well, I can't guarantee that a failing pedal is your problem, though it certainly seems that way. It might be worth looking up under the dash with a flashlight before spending $$$ on a new pedal.

Del said:
Not cast, but certainly understrength for fatigue cycling
Right, 164 clutch pedals aren't made from castings (like the door handles). Don't know what they were made from - perhaps Soviet steel, or recycled paper clips, or recycled Soviet paper clips. Irrespective of material, the design was poor, with that kink between the pedal and the lever arm.
 
#5 ·
Not cast, but certainly understrength for fatigue cycling (I think I'll inspect the one in my 91S soon).

The door handles, yes. Alfa cast door handles, both inside and out, have always cracked. My Sprint GT had outside handles break, but I learned how to repair them without it showing. Alfa door handles ever since have always been suspect, cracking now and then, esp if manhandled.
 
#8 ·
Yes, it is a classically easy stress analysis design calculation to properly size this part for the loads AND material allowables. In general, the basic reliability problem Alfa has had through the years is their use of cheap and lousy understrength metals for components.
 
#9 ·
Certainly good to check for a mechanical failure of the clutch pedal arm under the dash...I'd also check the basics, though.

1 - Verify clutch dampener/puck under the air filter is gone - this caused a lot of problems and the clutch works better without it.

2 - Did you replace the rubber hose to the slave? Probably not the problem, but old hoses can swell inside and cause problems. Now is the time to do it.

3 - Check that its bled properly. I've done a couple, and it takes a lot of work to get all the air bubbles out. Remove slave from trans, use a large C clamp to keep push rod in slave cylinder, and then have a helper push in clutch as you crack bleeder valve open. Repeat the "push clutch-open bleeder-close bleeder-release clutch (pull up)" process many, many times, while keeping an eye on the fluid level in the brake fluid reservoir. Keeping the slave as high as you can during the bleed process will help air bubbles make their way to the top and out of the system. My guess is that it hasn't been completely bled and you have some air in the lines still.
 
#10 ·
well I had my slave replaced and she is working well except (always something right?) mechanic told me the clutch pedal pivot thingie (my terminology) was failing or worn... sigh.. is this part still available and is this a doable project or does she go back to the shop? thanks!!
 
#11 ·
So what is the problem? Do you have excessive play in pedal? Is spring cartridge working OK? Little more info needed.

Pivot clevis pin or hole in pedal or master cylinder yoke can be worn for the pin. Pedal lever arm can be cracked.

Report your findings.
 
#12 ·
Hi Steve,

the pedal goes to the floor before it disengages the clutch, just had the slave replaced.. clutch is now working well .. the pedal does not always return. The mechanic said the pivot pin is worn. The pedal is also noticeably not even with the brake pedal.
 
#14 ·
If the pedal's not coming all the way back, that's not normal.

It's not sucking in a full complement of hydraulic fluid to push into the slave cylinder.

Sometimes things don't get translated well. Just think of it as the Master Cylinder ("Pump") and the Slave Cylinder.

The only thing I will say about the mechanic's excuse, is "that dog won't hunt."
 
#15 ·
The pedal pivot wears quite early on. There is no economically reasonable fix. It should not affect the clutch operation.

Failure of the pedal to return on its own may result from a broken or faulty internal spring in the MC which helps the piston and its seals return to resting position.

Why only replace the slave cylinder? How was that fault diagnosed as compared to faokure of the MC?
 
#17 ·
I got my clutch pedal feel back to normal yesterday after re-bleeding air out of system. Did you get yours working better?
 
#18 · (Edited)
I haven't been able to get back to it until just now.. reading your posts and about to head out to look at it again. It is a 91 base model
. When I said slave I was talking about the part on the transmission.. don't know why Alfa calls it the master :) I sure don't want to have to work on the master under the dash.. my body doesn't twist and bend like it used to. I will bleed it myself and see if I can't get a better feel to it. I just drove it around the block, it wouldn't go into reverse without grinding, my foot was pushing the pedal to the floor. I was able to shift into all the other gears, but with my foot to the firewall... wondering about this mechanic? when I bled the system in order to even drive it to his shop I had better pedal than what he delivered to me. but mine was leaking. It does not appear to be leaking now.. the reservoir is still full so that is a plus
 
#19 · (Edited)
It can be a real bear to bleed out the air. I actually had to bleed the master under dash using pressure bleeder with low pressure attached to brake reservoir. Then I ended up with slave cylinder off the transmission and held it elevated up high as far up as the hose would let me. I finally even had rubber boot, piston and spring out of slave and poured in fresh fluid into empty chamber while holding it straight up.

Reinstalled spring, piston, plunger and boot and then reinstalled it into mount on transmission.

I also don't have the "hockey puck" damper in the system. If installed it mounts to air cleaner support bracket. If you have it installed, I suggest you disconnect/remove it and then hook just the one hose going to it from firewall directly to slave cylinder.

My wife helped me finish the final bleeding by pumping clutch pedal and holding it about 3 times while I opened bleeder on slave to get last of air out.

Pedal now at same height as brake pedal and almost no free play in pedal now before the clutch slave starts to move. Clutch release and shifting smooth as can be.

Because I also had to change out to clutch master cylinder and the pedal had come up above the brake pedal when the master disconnected it bent the cruise and brake light switches mounting bracket. I had to bend the bracket back towards pedal switch stops to shut off brake lights and for cruise switches to touch each pedal, too.
 
#20 ·
awesome I appreciate the wisdom and experience here! so I woke up this morning and decided I am going to give it a shot at bleeding.. I couldn't believe the amount of air bubbles coming out. Makes me wonder if that shop even attempted to bleed the system after replacing the slave. It still isn't perfect and I imagine if I did all the above Steve, it would be much better.. But at least now it is drive-able!!!! yay I drove around town for a bit after I did all that and couldn't wipe that smile off my face... yes I remember now why I love Alfa's...so now still so much to be done...I will search for how to fix the speedometer to show actual or close to speeds... now it shows I am going 10 mph slower than my gps indicates.
 
#21 ·
congrats on the drive...
it would be nice to be able to pump new fluid in and push the old stuff out. Did that on a motorcycle and the bubbles kept coming out till the new fluid started to flow. The color of the old stuff was not the same. Not sure is that is a possibility on the 164.
 
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