93 2.3 S-cab MO5D 2wd:

I have the clutch Hydraulics completely removed, with a new slave.

Trying to bleed it prior to installation. Tranny was pulled because after 1/2 mile of driving, it was impossible to shift (without rpm matching). Seemed like heat would cause the slave to lose travel, because I could let it cool off and it would shift like a champ again until it got warm.

So, I gravity filled the new slave, got some air out by just cracking the slave bleeder. When the assistant pushed against the slave spring he could feel fluid backflow for that full compression stroke. We then used the master to push the slave from its compressed position (assistant holding the spring still compressed). It has good force, easily overcoming the assistant and the spring pressure for 1/2 of the total available slave travel.

My question is: How much of the "available" clutch slave travel stroke should the Master be able to push?

I have bled it repeatedly in every available combination of conditions possible, and I no longer get any air. I have the Master oriented/tilted opposite of the installed position, slave slightly higher and the reservoir higher still so air SHOULD be forced to the slave when bleeding.

I've tried bleeding while the assistant holds the slave compressed, which yielded no travel gain. At one point we hydraulic locked it (could not push the master at all), so we bled some fluid and still get exactly 1/2 of the slave's total stroke.

I got really lucky with the first 93 a couple weeks ago. Pulled that tranny because the flywheel teeth were gone, nothing for the starter to engage! Slave quick disconnect didn't leak a drop, I didn't bleed it at all, just reinstalled the tranny and reconnected the QD and that clutch was perfect.

If somebody can tell me that the Master can only push the slave 1/2 of its available stroke, the tranny will go in tonight. Otherwise, I'm buying a new Master (after I disassemble it, look at the seal, etc - can't help myself). I really don't want to spend any more money if I don't HAVE to. I got these two 93's to fix up and sell to make enough $$ to fix my 2000. I'll drive the 93 I'm working on now, while I fix the 2000 (4 BJ's, I/O tie rods, water pump, steering rack, and shocks).

Cliff's Notes: Slave has say ~3'' of total travel "capability". My Master will only push it for 1/2 of that total available stroke. Is the Master bad?

I guess I could clarify a bit: When I push the Master, the slave responds immediately. Once the Master is fully-stroked, the slave has only moved 1/2 of the total travel "available". The spring pushes it the rest of the way out.

 

Be careful bleeding the hydraulics with the transmission not mounted. I destroyed a slave cylinder that way because as pressure is applied it has nothing to press up against and over extended blowing out the seals. The trans should be bolted into position in order to properly bleed the system to my understanding.

 

Noted.

"We then used the master to push the slave from its compressed position (assistant holding the spring still compressed). It has good force, easily overcoming the assistant and the spring pressure for 1/2 of the total available slave travel."

and:

"I've tried bleeding while the assistant holds the slave compressed, which yielded no travel gain. At one point we hydraulic locked it (could not push the master at all), so we bled some fluid and still get exactly 1/2 of the slave's total stroke."


We're not "forcing" anything but using hand pressure holding the slave compressed. The Master moves it, but only 1/2 of its possible stroke.

I'm wondering if, when installed, that "overtravel" is simply spring pressure on the clutch fingers.

I really just need to know the slave's total travel "installed". I just hate to put the tranny back in and find out the Master is bad, making me bleed it with the slave and tranny installed. And I REALLY don't want to drop the tranny again (it's not installed yet).

 

Yea....none of the clutch hydraulics need bench bled.....meaning...everything should be all mounted up.

I've had alot of clutch component replacements in my ranger.....i'm on the 4th slave and 2nd master. The only difference i've found between a failing master and a failing slave.....is the master gets noisy.

Proper way to bleed clutch:

gravity drain till full fluid coming out.
slowly press the clutch pedal, while holding all the way down, open bleeder, immediately close.
repete a couple times.

(shortened up how-to...you sound like you might know your ****)

 

Tonight should tell the tale.

I'm gonna put the tranny back in and see what happens, I guess.

Worst case, I have to replace the Master. Just didn't want to spend that $$, and I sure don't want to pull the tranny again if it won't bleed out all the air. I do have enough sense to bench-bleed the new master, by depressing the QD (or hooking up the old slave). I'm pretty confident that if properly bench bled, disconnecting it with the slave QD, then re-connecting it, that I won't have to bleed anything at all.

I seem to recall from reading the Haynes manual (at my leisure) that the slave has X amount of travel INSTALLED, while viewing through the inspection port. I loaned that POS manual out about a month ago (I have a Ford CD manual) so it isn't handy to read.

I'm hoping that I'm over-thinking this system (and the over-travel is normal).

 

Overthinking.....i think yes. I'm just afraid that you may have ruined the new slave.

I'm not judging you by bench bleeding the master or the slave....but none of the Ford Service manuals i've seen said anything about bench bleeding the clutch master or the clutch slave. Nor do the Chiltons/Haynes manuals.

 

No worries, it is functioning just as it did the first time I hooked it up and pressed the Master (after the gravity bleed). I'm sure it didn't ruin it in any way, shape or form.

I'm just curious why there is so much free play, following the Master's hydraulic pressure actuating the slave. I assumed there would be more slave travel. It's not that the master keeps moving and the slave stops. The slave starts moving when the Master is pressed and stops when the master bottoms out, but the slave has only travelled 1/2 of the distance it CAN. I guess the remainder is built-in "spring pressure" slop.

Thanks for the opinions, guys.

I'll update this thread tomorrow or so, after I get it back together.

If anybody's got a Haynes manual and would look it up, I'd still like to know the dimension that they quote. It was stuck in my head that Haynes said to look for X amount of slave travel, which would have put my mind at ease that this thing is good to install (questioning the Master, slave is new). I was worried that the slave and master weren't a matched set, since I've read of some year Masters having a larger bore, therefore it would displace more fluid, making the slave extend further. We shall see.

 

Went in like buttter.
Relied on the QD, didn't bleed.
Drove it to the parts store.