Alfa Romeo Forums banner

1 - 4 of 4 Posts

·
Registered
Joined
·
1,765 Posts
Discussion Starter #1 (Edited)
Well, something had to be done about my clutch pedal being very heavy and sometimes sticking on the floor. I bought a new slave cylinder (master cylinder in AR docs) - the one for the release fork - quite unnecessarily as it turned out.

I planned to replace the two flex hoses (to the damper, and to the cylinder), but couldn't get the large nut undone where the rigid line meets the hose, under the coolant tank and tangled with the brake lines. Eventually I gave up and drained the fluid through the bleed nipple - it came out perfectly clean, and the clutch pedal pushed down with ease. So I considered that the hoses were probably OK.

I replaced the fork-pushing cylinder (my new name for it!) - which tapped out of the bracket easily, no corrosion (!) The new cylinder was quite bright 'silver' yet seemingly not plated - cast steel rather than cast iron? I gave it a couple of coats of silver paint, and painted the bracket as well. I fitted the new cylinder to the removed bracket, opened the bleed nipple, pushed the piston in, closed the nipple, and let it draw new fluid through - easy. I bolted the bracket into place.

Then I discovered that the pedal was stuck down - lifting the pedal did not bring the pedal-cylinder piston with it. So I unbolted the bracket for the fork-cylinder again, let that expand, then pushed it in sharply. That popped the pedal back up. It also produced bubbles in the fluid reservoir.

I bolted the bracket up again and discovered that the clutch was now working nicely. The right thing to do would have been to have stopped there, job done in an hour. Foolishly, I decided to carry on and bleed it.

The electric seat makes a good pedal-pusher when combined with the broken handle of a garden hoe. That way, the system was under pressure ready for when I undid the bleed nipple. All looking good, no air came out.

But suddenly the pedal became very stiff and heavy, accompanied with a 'swirling' sound, as has been decribed here before.

At this point, I decided to remove the damper - to see if it made any difference. I bypassed it just as Alfisto Steve said. That made a huge difference - swirling noise gone, and now I could push the pedal down by hand (also as Alfisto Steve said). So, problem solved. I tried bleeding the system again but I almost wonder if the system may be self-bleeding - would air find its way back up to the highest point (the reservoir) as the pedal returns? It seems that even if the pedal starts 'down' after bleeding, pulling it back up restores the system to working condition.

So I think the damper was probably the problem all along, but at least the slave, err, fork-pushing cylinder was cheap enough at US$25.

Now the last two pics. Note the installation of the pedal cylinder - in front of the pedal. That means easy access and changing it really looks quite easy, though perhaps it's tricky to get to it somewhere behind the steering rack. I think this must apply to right-hand-drive only?

The clevis pin through the pedal appears to have quite a lot of slack on my car - a couple of centimetres 'free travel' at the pedal before the pedal cylinder starts to move. The pin seems to be too small for the holes it passes through. It looks a bit tricky to remove the clutch pedal, so I guess I'll improve it a little by sleeving the pin, and leave it at that.

I still wonder, is there usually 2cm free travel in the clutch pedal? And do I need to keep trying to bleed the system?

Thanks for reading this far!
-Alex
 

Attachments

·
Premium Member
Joined
·
26,815 Posts
I love to read a success story. However, in my case on my rescue society 93L the hose you could not get off rigid line was bad so even after removing damper clutch pedal was hard to push and stayed down or was very slow to come back up. Once I changed hose all was well again.
 

·
Registered
Joined
·
1,765 Posts
Discussion Starter #3 (Edited)
I love to read a success story. However, in my case on my rescue society 93L the hose you could not get off rigid line was bad so even after removing damper clutch pedal was hard to push and stayed down or was very slow to come back up. Once I changed hose all was well again.
Thanks for the advice! Happily, clutch pedal in mine is still nice and light. I think if it isn't, I shall next approach hose from underneath car on hoist.

I have a question about the clutch pedal. The hole for the clevis pin (attachment to the master cylinder/'pump') has worn oval (many years of the heavy clutch, I guess) in both the pedal and the master cylinder fitting. The two slacknesses add together and along with ridges worn in pin give about 1" slack at pedal. I can't decide on best remedy.

I think perhaps drill out hole in pedal and press in sleeve with same ID as standard pin. Then, weld a washer each side of the master cylinder fitting and use a longer pin. I guess if pedal hole was big enough, maybe a bearing could go in there, which would give me a nice warm feeling inside.

Or should I try just filling clutch pedal hole with weld and drilling a hole in it? Is it possible to drill a hole in a MIG weld anyway? I've never tried.

Or maybe file flats on the top and bottom of a larger pin?

EDIT: Decided to add a couple of pics to make the situation clearer - getting the internal circlip out of the master cylinder (to release end fitting) was an awful job!

Oh, I know! - maybe just drill out all the holes to 10 or 12mm and find a new, larger pin? ... would be confusing at master cylinder replacement-time, but end fitting could be swapped over, only one eaaaasy circlip to remove ;)

Thanks,
-Alex
 

Attachments

·
Premium Member
Joined
·
26,815 Posts
As you say you have a couple options. If you can find correct bigger size pin to match drilled out holes in both pieces maybe way to go.

Drill/reaming both pieces and installing bushings the correct way if you have a new or good original size clevis pin.

Welding pedal and drilling new hole in pedal will work, too but maybe a bit harder to do that to MC plunger pivot hole.

Clutch must have been super hard to push to wear both holes oval like that for a long time.
 
1 - 4 of 4 Posts
Top