TECH 101 clutch MC/Slave bleeding procedure!

riotwarrior · Feb 12, 2013

Well I've read quite a bit on here regarding clutches and master cylinders and slave cylinders and all the various bleeding procedures people use, myself offering in some tips too....

Well I decided to review the section on Clutch bleeding for our trucks in my Manual from Ford. There is not one mention of standing on your head....clicking your heels 2 x or any other absurd point to which I have had the privilege of reading on here and other various sites.

Now I don't have a scanner and my phone does not do good close up shots so I cannot take a picture of said page, however for anyone whom doubts the integrity of this post, I have included a pic of my TWO FORD manuals to offer some validity to what I'll be posting.

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I'm posting WORD FOR WORD from my Ford manual. If you have any questions...ask away but I'm only posting what this manual has written.

Without further ado ......and this is exactly what it says...verbatim

Bleed Procedure for External Slave Cylinder

7.3 Diesel and 7.5 Gas

Clean Reservoir cap and slave cylinder in area of the tube connection.
Remove slave cylinder from the transmission bell housing.
Use 3/32 inch diameter punch to drive out the pin that holds the tube. Remove the tube from the slave cylinder and place the tube end into a container for waste fluid. The tube will still be connected to the master cylinder, so keep the reservoir cap tight to minimize fluid loss.
Hold slave cylinder so that the connector port is at the highest point, by tipping the cylinder approximately 30 degrees (FIG 9). Fill with approved DOT 3 brake fluid through connector port. It may be necessary to "rock" slave cylinder around or push gently on the pushrod to expel all the air. Pushing on the pushrod too hard will cause fluid to spray out of the connector hole. Cleanliness is very important. Be sure not to let any moisture or foreign matter to enter the slave with the brake fluid.

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When all of the air has been expelled from the slave cylinder and no more bubbles come out of the port hole, reinstall the slave cylinder back on the vehicle.

NOTE: Some fluid will be expelled from the connector port, as the pushrod is compressed attaching it to the transmission and lever.
Gravity fill the master cylinder and tube as follows: Remove the reservoir cap and diaphragm, fluid show flow out the open end of the tube into the waste container. Be sure to keep the reservoir full. When fluid is flowing out in a steady, uninterrupted flow and fluid is level with the step in reservoir, reinstall the cap and diaphragm. Install end of tube to slave cylinder body.
System should now be bled and functioning properly. To verify proper system function set barking brake and put vehicle in neutral. Start vehicle and shift into reverse gear. If gears grind, other components may be causing the concern. Check the slave cylinder pushrod travel as detailed in section 16-01 Clutch General Service.

NOW this is me making NOTES....this is a direct copy of the Section 16-01for measuring pushrod travel...

Bearing Travel Measurement

F-Series with 7.3L Diesel and 7.5 Gasoline Engines

With the clutch pedal depressed fully to the floor measure the external slave cylinder pushrod travel.
The pushrod should extend 11mm (millimeters) or (0.43 inch) minimum. Do not replace the clutch hydraulic system if the measurement exceeds this distance.

NOTE: If the slave cylinder travel does not meet the travel requirements, check the hydraulic reservoir fluid level.

RLDSL said:
WARNING ...These are great instructions in the manual , *but* for those who are missing the little plastic pushrod retainer strap on their slave , or it has been broken ( as the instructions all seem to tell folks to do when installing the things ) someone would have one HECK of a time getting that slave back on without the strap, and may find it impossible and wind up having to go purchase a new slave cylinder just to get the friggen retainer strap ( dont ask me how I know this

Thanks Robert for this great bit of info....HEED this warning!

. . . . . E D I T . . . . .

UPDATE:

I have had very very good success installing used or bled slaves of late in a very simple method.

I take a small 1/4" drive socket thats just a bit smaller than the ball end of the push rod, and a 1/4" drive nut driver handle that you stick in the socket. Then slide the slave on as far as you can, then use the socket/nutdriver to press the pushrod in untill just past the clutch for arm and **** the ball end over onto the clutch fork.

I've done the above procedure many times. I was called for assistance by BigredCrew for this and had him do this the first try when I told him how. He had tried many times previously and could NOT do it.

Hope this helps

Towcat method as follows....

towcat said:

How about a weird idea?
For years I was concerned about letting the clutch slave fully extend and the consequences...ie. the whole thing falling apart. Until I did a post mortem on a bad clutch slave after doing a nono. While it was out of the bracket and cluch fork, I stepped on the clutch pedal and intentionally blew it up. Got news... it takes a fair amount of pedal effort to kill one in the fully extended position. So here's what I did on my most recent clutch system installs. One. install the master and the nylon line. fill with fluid and let it gravity bleed out. Two, remove the slave from the retainer bracket(if installed on the trans) on the trans and allow the pushrod to extend fully or if the slave is a new unit, disengage the retainer straps holding in the pushrod and allow to extend. Three, find the appropriate sized allen wrench for the bleeder screw on the slave. Four, install the slave on the nylon line when you start seeing fluid dripping out of the line. Five, here's where it gets interesting... brace the slave pushrod against a hard object such as one of web pockets on the trans and push in the pushrod by hand after opening the bleed screw. Six, when the pushrod is in the fully retracted position, close the bleedscrew. Allow the pushrod to once again fully extend SLOWLY. Seven, repeat steps five and six until you start getting a shower. This only took two or three repeats for me. Another indication that the slave is filling up is it will become harder to push in due to the amount of fluid filling up the slave. That is a good thing. Eight, if you are intalling a new slave, reinstall the retainer strap and install the slave assy. If you don't have the retainer strap anymore, open the bleed screw a little, so when you fight in the slave assy, the pushrod will go in a little easier. I had the second of the two to work with
Here's my premise for the whole idea....when working properly, the pushrod travel on the clutch slave is 1/4 to 1/3 of the total travel the salve is capable of handling. By fully stroking the slave unit, more air is displaced and more fluid is drawn in from the vaccumn, therefore tha job goes quicker. Fact of the matter is you are going to get a brake fluid shower either way, minus well make it alot shorter
yes, I can already see the ****** reference inuendo coming......

Click to expand...

Thanks Towcat for that one!

G. Mann's Method is as follows....

G. Mann said:
Ok guys. This is what works for me, every time. I've been using it for over 25 years [learned it while working only on foreign cars which are a real pain to bleed].

G. Mann said:
Required:
1. Your clutch slave must have a nipple style bleed screw. [Some of the new replacement clutch slaves only have a bleed screw with a hole in the side, I've had some luck replacing those bleed screws with new nipple style bleed screws from the "self help isle" at the local auto parts house, your mileage may vary on that trick]

2. Purchase an old fashioned pump oil can that has a decent sized cup on it to hold fluid.

3. Buy about 3 feet of clear poly hose from your hardware the size that will just press fit onto the bleed nipple. Cheap is OK.. you are only going to use it and discard it.. [unless your as tight as I am.. ]

4. Clean bottle of brake fluid.

Prep Required:

1. Press the clear poly hose onto the pump oil can spigot. Slip it on far enough that you get a good seal... you don't need a clamp.

2. Fill the pump oil can with clean brake fluid and after you open the bleed screw on the slave cylinder, press the other end of the poly hose onto the bleed screw nipple.

3. Remove the cap from the clutch master, it should be empty at this point. Set the cap on the master and screw it on very lightly.. leave it loose. [If you don't leave the cap on loose, in the next step you will squirt brake fluid onto the hood and cowl, make a mess, and maybe pull up your paint job.. ]

4. Start pumping brake fluid from the hand pump from the bottom UP to the clutch master... You can see the fluid move through the clear poly hose along with the air that is in the hose... when the hose shows solid fluid, stop and check your clutch master for fluid. at this point, it may still be empty.. put the cap back on and pump some more.. check again.. when you get about 1/2 inch of clean fluid in the clutch master reservoir your clutch system is fully bled, close the bleed screw. Fill the clutch master to proper level, tighten cap.

5. You are done.. clutch will be bled and work as it should... no air..

I have yet to have this system fail in 25 years. Air wants to travel up, it's lighter than the fluid.. by using fluid from the lowest point to push the trapped air out, it vacates the system perfectly..

If you try to push air down with fluid.. the heavier fluid goes past the air bubbles and traps it.. you never get a clean bleed.

Total cost should be less than $15 for poly hose and hand oil pump [buy a good one, you will want to use it next time]. Total time to bleed clutch should be 10 min or less..

Try it.. You will throw rocks at every other method.

K folks this about sums up the procedure and check hope this is clear, and easy to understand.

Here is a link to my slave install video

http://www.oilburners.net/forums/sh...-ZF-Slave-cylinder-install&highlight=Tech+101

Thanks for reading

Al

79jasper · Feb 13, 2013

Very good. That's the way I read from a different site out of a shop manual to do it.

No pixie dust here.

There is the "alternate method" of pressing the slave rod in to expell air also.

ZWilson07 · Feb 13, 2013

Nice thread!

Hopefully this cuts down on the threads of bickering back and forth to take it off together, or not.

Im sure it can just be a little overwhelming and nerve racking if you seperate them and trying to get it back together and working perfect again if its a first time for someone.

typ4 · Feb 13, 2013

That is definately the book method.
This is how I have done them all and it works for me, cause I never have help, fill master, pump up several times then hold pedal to floor, it wont feel like any pressure , sit there for 3 or 4 minutes, let pedal up. if you look at the master it should have some air bubbling, when it stops refill if needed, repeat , after 3 or 4 times I have had a good air free system, you just have to let the air rise to the top, and it does work better on warmer days/or with engine running for heat.
JM2C

RLDSL · Feb 13, 2013

Personally, I like the *attach a Motive Bleeder to the clutch master cylinder , pump it up, open up the bleeder screw on the slave and watch all the air go by-by and be done with it* method... but then again, I'm inherently lazy LOL

little for warning... THose are great instructions in the manual , *but* for those who are missing the little plastic pushrod retainer strap on their slave , or it has been broken ( as the instructions all seem to tell folks to do when installing the things ) someone would have one HECK of a time getting that slave back on without the strap, and may find it impossible and wind up having to go purchase a new slave cylinder just to get the friggen retainer strap ( dont ask me how I know this :backoff

riotwarrior · Feb 13, 2013

RLDSL said:
...warning... THose are great instructions in the manual , *but* for those who are missing the little plastic pushrod retainer strap on their slave , or it has been broken ( as the instructions all seem to tell folks to do when installing the things ) someone would have one HECK of a time getting that slave back on without the strap, and may find it impossible and wind up having to go purchase a new slave cylinder just to get the friggen retainer strap ( dont ask me how I know this

Thanks for that little helpful hint.

I took the liberty of a lilttle edit and included a quote from you in the article.

Thanks again

Al

79jasper · Feb 13, 2013

The broken/missing strap dilemma is a PITA,
But I just used a small ratchet strap to pull it in.

Black dawg · Feb 13, 2013

My method that has been working good for me on pretty much everything I have tried it on is, with reservoir partly full, with lid on but rubber piece inside removed, hold the hose of your mityvac hand vac. pump over the small vent hole it the cap. I usually put a good vac. on it for 30 seconds or so, and then go and run the pedal a few times. Usually end up repeating this 2 or 3 times, but has been working good for me. It is pretty amazing how quickly the level will drop in the master just putting the vac. to it.

RLDSL · Feb 13, 2013

79jasper said:
The broken/missing strap dilemma is a PITA,
But I just used a small ratchet strap to pull it in.

I tried a ratchet strap, ended up eating teh thing a few times I tried all kinds of things... After shaking a dead chicken over it while wearing a grass skirt didn't work, I gave up and bought a new slave cyl.

riotwarrior · Feb 13, 2013

RLDSL said:
I tried a ratchet strap, ended up eating teh thing a few times I tried all kinds of things... After shaking a dead chicken over it while wearing a grass skirt didn't work, I gave up and bought a new slave cyl.

I'm not fully following this issue actually....are you not able to push the rod into the slave? Is that the problem?

I guess gotta try it myself to find out eh????

LOL

Fortuately I've only ever removed systems....sealed and working... LOL

79jasper · Feb 13, 2013

It was a PITA even using the ratchet strap. But I finally got it to stay on. Had to tighten it some, then slide the rod over, tighten, slide over. It was a process :lol

With the rod extended, there's no way it's going into place. I tried pushing the rod in with the slave mounted, but could only get it even with the end of the clutch fork. But that was pushing with my thumbs.

Even if you pull the system whole, you still have to compress the slave to get it into place.

Black dawg · Feb 13, 2013

I am not understanding why you guys are having a hard time getting the slave back in place? I usually put the rod in the clutch fork and push it in until the slave will slide into place. Many times, I just push the rod in and hold it by hand and install the slave. :dunno

redneckaggie · Feb 13, 2013

oh come on guys I have compressed the slave multiple times with a 2x4 ad a hole started in it an the end of it grounddown where you just c clamp the board to the fork, rest the rod in the radius and compress the slave, then tap the rod over onto the fork

RLDSL · Feb 13, 2013

redneckaggie said:
oh come on guys I have compressed the slave multiple times with a 2x4 ad a hole started in it an the end of it grounddown where you just c clamp the board to the fork, rest the rod in the radius and compress the slave, then tap the rod over onto the fork

Some of us may have the years of experience behind us, but unfortunately the old worn out bodies to go with it. These days my favourite chair has wheels on it. It's all I can do just to crawl UNDER a friggen truck any more . having to go caveman on parts to get them to go in while balanced on one shoulder is completely out of the question anymore . If I cant get it to go in without a major fuss, I'll rig a tool, if a tool cant be rigged, I'll get another one. It isnt worth killing myself over.
My days of stuffing transmissions with my knees are LONG gone :rotflmao

Enjoy it while you can... youre gonna get old too ;Really

franklin2 · Feb 13, 2013

I will agree with the others, I had a hard time getting the rod compressed and holding it in, and then pounding the clip that holds the slave onto the bellhousing.

As far as the factory instructions go, the factory instructions will always work, but you have to admit they go overboard sometimes, and most mechanics find an easier and quicker way. They couldn't make any money if they didn't.

TECH 101 clutch MC/Slave bleeding procedure!

riotwarrior

Supporting Member

79jasper

Chickenhawk

ZWilson07

Cowboy

typ4

Supporting Member

RLDSL

Diesel fuel abuser

riotwarrior

Supporting Member

79jasper

Chickenhawk

Black dawg

Registered User

RLDSL

Diesel fuel abuser

riotwarrior

Supporting Member

79jasper

Chickenhawk

Black dawg

Registered User

redneckaggie

rebel w/o a cause

RLDSL

Diesel fuel abuser

franklin2

Full Access Member

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