I've never heard of clutch pedal fade before but that is the only way I can describe it. It only happens sometimes and doesn't seen to affect shifting but sometimes the clutch pedal falls to the floor with less pressure than normal, or what feels normal. It also feels stuttery when this happens. I have always thought that it might be because the trany fluid was low but when I changed the transmission fluid it didn't go away, in fact it seems to have gotten worse. I don't think it could possibly be the return spring. Can any body possibly shed some light on the subject?
Thanks
Just the clutch getting worn out? I've never had something like that happen, but I drive Hondas
(04-27-2010 09:57 PM)bmoyers Wrote: [ -> ]I've never heard of clutch pedal fade before but that is the only way I can describe it. It only happens sometimes and doesn't seen to affect shifting but sometimes the clutch pedal falls to the floor with less pressure than normal, or what feels normal. It also feels stuttery when this happens. I have always thought that it might be because the trany fluid was low but when I changed the transmission fluid it didn't go away, in fact it seems to have gotten worse. I don't think it could possibly be the return spring. Can any body possibly shed some light on the subject?
Thanks
Man... that's a doozy! There are a number of possibles and after I post, there may be others that post ideas as well. Hopefully one will hit the BINGO!
1. Clutch pedal fade usually refers to heat building up and cooking your fluid... it usually happens in brakes (like "spirited" mountain driving) but if your clutch is doing it, you've got some major problems causing that much heat. I don't think it's fade although I have no doubt that's how it feels.
2. Tranny Fluid - I don't think that level or quality of fluid would affect pedal travel like that.
3. Check your hydraulic fluid on clutch (and brake) and see if it is clear and to the line. If it is low on the clutch side, you know that's your problem. Could be seals are going bad in master or slave cylinder. If fluid is dark or has black matter floating in it, it is likely seals are breaking down and bubbles are being sucked in. Visual inspection may show fluid leaks but you can have one going bad WITHOUT fluid leaks... it does a "blow by around seals" kind of like a liquid shock absorber spilling fluid over from one side to the other.
4. Air in your line - that is most likely and easiest (cheapest ) to fix. If you have air in your line, it would feel exactly like what you describe. If you had a metal bar between your pedal and the clutch, when you step on it, it would travel exactly the same distance as your foot did. Hydrualic fluid works the same way unless there is an air bubble which compresses and steals the stroke of your pedal travel. Air bubbles are a PITA and can hide in Master cylinder, line or slave cylinder. If you are not sure and not familiar with bleeding hydraulic lines, take it to Tire Kingdom or whereever and have them bleed it. They have the equipment to insure bubbles are pumped out. Then if the pedal goes soft, you know bubbles are not the cause and master or slave cylinder are suspect.
5. People who have complained of true clutch pedal fade often notice it after rain or car wash. That is ... seals are warm from use and cold water splashes on the cylinders chilling them ....shrinking the seals and pedal is mushy for 20 minutes or more. Not likely but see if you note conditions when this happens. Also, do you get pedal back by pumping it?
Hope some of that helps!
Ted
This is on a Fiero I assume?
Does the clutch slip any? How close is the exhaust routing to the slave cylinder?
Thanks that does help and I love your signature phrase
(04-27-2010 10:27 PM)Theodore Wrote: [ -> ] (04-27-2010 09:57 PM)bmoyers Wrote: [ -> ]I've never heard of clutch pedal fade before but that is the only way I can describe it. It only happens sometimes and doesn't seen to affect shifting but sometimes the clutch pedal falls to the floor with less pressure than normal, or what feels normal. It also feels stuttery when this happens. I have always thought that it might be because the trany fluid was low but when I changed the transmission fluid it didn't go away, in fact it seems to have gotten worse. I don't think it could possibly be the return spring. Can any body possibly shed some light on the subject?
Thanks
Man... that's a doozy! There are a number of possibles and after I post, there may be others that post ideas as well. Hopefully one will hit the BINGO!
1. Clutch pedal fade usually refers to heat building up and cooking your fluid... it usually happens in brakes (like "spirited" mountain driving) but if your clutch is doing it, you've got some major problems causing that much heat. I don't think it's fade although I have no doubt that's how it feels.
2. Tranny Fluid - I don't think that level or quality of fluid would affect pedal travel like that.
3. Check your hydraulic fluid on clutch (and brake) and see if it is clear and to the line. If it is low on the clutch side, you know that's your problem. Could be seals are going bad in master or slave cylinder. If fluid is dark or has black matter floating in it, it is likely seals are breaking down and bubbles are being sucked in. Visual inspection may show fluid leaks but you can have one going bad WITHOUT fluid leaks... it does a "blow by around seals" kind of like a liquid shock absorber spilling fluid over from one side to the other.
4. Air in your line - that is most likely and easiest (cheapest ) to fix. If you have air in your line, it would feel exactly like what you describe. If you had a metal bar between your pedal and the clutch, when you step on it, it would travel exactly the same distance as your foot did. Hydrualic fluid works the same way unless there is an air bubble which compresses and steals the stroke of your pedal travel. Air bubbles are a PITA and can hide in Master cylinder, line or slave cylinder. If you are not sure and not familiar with bleeding hydraulic lines, take it to Tire Kingdom or whereever and have them bleed it. They have the equipment to insure bubbles are pumped out. Then if the pedal goes soft, you know bubbles are not the cause and master or slave cylinder are suspect.
5. People who have complained of true clutch pedal fade often notice it after rain or car wash. That is ... seals are warm from use and cold water splashes on the cylinders chilling them ....shrinking the seals and pedal is mushy for 20 minutes or more. Not likely but see if you note conditions when this happens. Also, do you get pedal back by pumping it?
Hope some of that helps!
Ted
It is on a Fiero and I am not familiar to where the slave and master cylinder are for it.
Oh and the clutch does not slip.
(04-27-2010 10:56 PM)bmoyers Wrote: [ -> ]It is on a Fiero and I am not familiar to where the slave and master cylinder are for it.
Oh and the clutch does not slip.
The master is connected to the pedal and the slave to the clutch fork. THat is if it has a hydraulic clutch...
What year Fiero?
'88 V6 with the gutrag 5 speed. I am fairly certain that it is a hydraulic clutch.
(04-28-2010 12:16 AM)mdenz3 Wrote: [ -> ] (04-27-2010 10:56 PM)bmoyers Wrote: [ -> ]It is on a Fiero and I am not familiar to where the slave and master cylinder are for it.
Oh and the clutch does not slip.
The master is connected to the pedal and the slave to the clutch fork. THat is if it has a hydraulic clutch...
What year Fiero?
(04-28-2010 12:29 AM)bmoyers Wrote: [ -> ]'88 V6 with the gutrag 5 speed. I am fairly certain that it is a hydraulic clutch.
Yup, it is. When does it tend to happen?
Thats actually a hard question to answer. It seems to be random, but if I had to pick a specific scenario it be as I shift after high revving. But it isnt always like that, just more often its like that.
(04-28-2010 12:49 AM)mdenz3 Wrote: [ -> ] (04-28-2010 12:29 AM)bmoyers Wrote: [ -> ]'88 V6 with the gutrag 5 speed. I am fairly certain that it is a hydraulic clutch.
Yup, it is. When does it tend to happen?
Have you ever changed the clutch fluid? That would be a good place to start.
is that different from changing the trans fluid
(04-28-2010 09:44 AM)bmoyers Wrote: [ -> ]is that different from changing the trans fluid
Yes. The clutch fluid is that which runs between the master and slave cylinders. In your case 9and most others) they use brake fluid. I would recommend Valvoline Dot 4.
It should be changed regularly just like the fluid in you brake system because it is actively hygroscopic and will absorb moisture. Once it absorbs the moisture the boiling point will lower and any ferrous metals in the system will corrode. If the fluid boils the pedal will get soft.
Dude thanks a lot you really know your stuff, I just looked it up in a Hans manual. Do you change it by sucking out the old fluid or is there a place to let the fluid run through like brake lines.
On another note would you happen to know how the set up is on a Saturn SL1 1994 5 spd? I do believe it is not the same set up, even though it has a hydraulic clutch.
Do you work on cars as a job?
There should be a bleeding procedure in the manual, just fallow that until clean fluid comes out.
There will be a very similar system on that Saturn, there isn't must variation in hydraulic clutch setups.
No, I'm a machinist by trade, working on cars is my hobby.