ok, so about every 3-4 days, I have to bleed the slave cylinder or it is nearly impossible to shift this thing.

10 pedal pumps, hold, crack bleeder. air bubble comes out, pedal is perfect. after a few days, the pedal is back on the floor. it is a daily driver.

replaced master cylinder twice. I am under the impression that no amount of bleeding can remove master cylinder air without turning the master upside down first, and for this reason, I am thinking the problem lies elsewhere.

I dont understand how the system could be getting so much air into it, without leaking a drop of fluid?

Not sure what the problem is, thinking maybe slave cylinder. is there anything else I should be looking at?

 

This video explains it best.


Another cause of this, is if the clutch disc was replaced with a non-self adjusting clutch, then your symptoms would occur.

 

if I had air trapped in the system somewhere, then the pedal would always be soft until it was completely bled out like the above procedure details.

My problem is that every couple days, I have more air in the slave cylinder. A quick pedal pump and bleed at the slave, and it is perfect again. If there was air trapped elsewhere, the pedal would never operate properly, correct?

its almost like the slave is sucking in air.

 

I understand what you're saying, there are many post with this problem.

All I'm saying is that the master cylinder has to be bleed first like in the video.

If that was done correctly and air is entering the system, the problem is the slave (sucking air past the seal because it's worn).

Also could be the pressure plate itself, if the self adjusting mechanism is at the end of its travel because the clutch disc is worn, the that would also cause this situation.

Was anything else replaced other then the master cylinder ?

EDIT:
Lets assume that there is also a number of small air bubbles in the master cylinder circuit (that includes the line up to the coupling where it connects onto the slave).
Not enough to affect the working proper working of the clutch though.
However after a few days, those smaller air bubbles accumulate in the slave cylinder, giving you a no clutch situation.

I would follow the bleeding procedure in the video first before going after another part of the system.

 

The master was bled properly, when I changed it both times (once on old trans, once on new)
New clutch when transmission was replaced. I believe it is self-adjusting, I bought the best unit Oreilleys had available. Either way, a brand new clutch shouldnt be wearing so fast that it needs the system bled every 3 days. If it was wearing that fast, I would imagine the clutch plates would be junk by now, as I have been driving the truck like this for over a year.
I used the old slave that was in the transmission that I purchased.

The only problem is that I had this same issue before I changed the trans and clutch, so I was questioning it being the slave.


But, if it is possible that the slave is sucking in air without leaking out fluid, then I am going to assume this is where my problem lies. Its what Ive been thinking for a while, but I wanted to see if I was missing something big

 

Obviously a new clutch isn't going wear that fast, now that I know that you replaced it.

If you are sure that the master cylinder has been bled properly, then the slave is worn out and or the wrong pressure plate has been put in.
It's common practice to install a new slave if you have the trans dropped.
Only use a Ford Motor Craft slave, the after-market ones only last for a year.

My gut tells me that even though you think you have bled all the air out of the master system, there is still air in it.
It has to be done like in the video, although I think if you used a vacuum bleeder, that would work too, but with the master cylinder and line disconnected from the slave, there should be virtually no movement in the master cylinder as demonstrated in the video.

Here's a photo of the right pressure plate, note the springs pointed out.

 

I cant find my receipt for the clutch, which sucks because I have a file for vehicle maintenance costs, and I am meticulous about saving receipts for occasions such as this :/

Ill try to get under there and take a look, but it is irrelevant at this point because either way the trans will have to come out. I could simply get a self-adjusting clutch after its ripped apart and I can check out the situation.


Even if there was air trapped in the line or in the master, after bleeding a fairly large bubble out of the system every few days for this long, eventually all the air would have to be gone. well, all the air that could be bled out in this configuration, I understand exactly how and where the air gets permanently trapped in the system.

BUT, if I had a permanent bubble trapped in the master or line, no matter how much I bled the system(while installed), the pedal would never work right, correct? Because after a couple pedal pumps and one quick crack of the bleeder, the system works perfectly, clutch disengagement right at the top of the pedal, nowhere near the floor.

I should also note that if I bleed the slave, let the truck sit for a week and jump in it, the pedal is still perfect. Whatever is going on is directly related to using it.

 

You may be able to see in the inspection hole in the bell-housing what pressure plate you have.
There should also be a record in you in-box of what you got from O'Reilly's and or on the web site if you created an account.

Honestly I don't have a solid answer to your comments.
One would think that eventually the air would bleed out, but it doesn't seem to.
This is after reading other posts here on the forum with other guys with the same problem.

I know the reservoir is quite small, (not trying to insult you here), but it doesn't take much for the level to drop so more air gets sucked in.
When the air accumulates in the slave, causing a no clutch situation, it could be sucking in more air through the reservoir with out you realizing it _ just something to check.

 

No worries, sometimes the best of us overlook the dumbest of things!
Every time I bleed it, I top it off, and the levels are nowhere near empty either. I could probably bleed it 5-6 times before getting near the bottom of the cup. I barely bleed off any liquid when I do it.


Oreilleys system of looking up past purchases is absolutely terrible unless you have a receipt in hand, unlike autozone where everything is saved under your phone number. I suspect that saves them a lot of cash on warranty items.

It almost seems like there is an air generator built into my slave cylinder! If I ever get the energy to yank the trans and swap the slave, I will definitely report back with a status update.

 

Yes, it does seem that your slave cylinder is @fault here....but given that I would highly suggest u replace it with a motorcraft slave cyl. Reason being is I’ve never heard anyone have a aftermarket one lasting any amount of time.... I do know there is a significant difference in price, so maybe shop around online for one to buy?

 

That is good to know. Reality is, with what is involved with replacing the damn thing, it is worth spending 4X the price.

 

The Ford slave and master is supposed to last the life of the clutch.

 

Replaced the slave cylinder. Problem solved!

picked up a new motorcraft slave on eBay for 100 bucks.