I have a 95' F150 4x4 (original owner) that I'm in the process of doing a transmission swap. The M5OD was on it's last legs, making all sorts of bad noises and frequently not shifting into gear. The replacement is a used ZF5-42 that I got from LKQ.

I want to take the clutch slave cylinder from the M5OD and put it into the ZF542. Once the tranny is mostly in position, will I need to bleed the slave cylinder, or will it retain fluid from before?

I've done lots of other work on Big Blue, but this is my first time pulling a transmission. I want to thank all those who post solutions at this site, because I never would have attempted a transmission swap without all the great information found here.

 

It will retain the fluid from before but it's not a bad idea to bleed all the old fluid out of the master and slave. The fluid absorbs moisture and gets dirty somehow and it's good to flush it out about every 3 years.
I do this on my brakes as well.

 

Yes it will require bleeding. On my two installations I found that the pedal had to be slammed to the floor aggressively to get a good bleed and firm pedal.

 

I have the transmission bolted into place and resting on the cross member and connected the clutch line hydraulic. So after going through quite a bit of fluid and no more air coming out, the pedal goes to the floor and doesn't return.

I'm wondering - I used the slave cylinder from the M5OD because it was less than 1 year old. Is it compatible with the ZF542? Is there something with the bleeding technique I should try?

 

Got the clutch going. A key part to the process is to rapidly depress the pedal a number of times, wait a few minutes and then repeat.

I did confirm that the slave cylinder is the same for the M5OD and ZF542.

Only differences I found so far with the swap is:
1) the harness to the reverse light switch needs to be spliced to make it longer.
2) the transmission mount to the cross member is different. I wasn't able to remove the one from the M5OD, and the ZF542 came with the studs broken off. I ground the studs flat and then drilled holes, and used a regular bolt and nut combination to secure it.

 

Not a good day. Just took out the garage door when it get caught on the hood with the truck still jacked up. I managed to clear the carnage of the door, started up big blue, and the clutch pedal is still soft.

I started with the transmission in neutral, then shifted in first and nothing happened. Also tried second with nothing.

What I am doing wrong to bleed the clutch?

 

Bleeding a Concentric Hydraulic Clutch Set-up .: Articles Have a read here. If it was me I would have fitted a new Ford slave cyl. just in case.
Also if 4x4 check that transfer case is not in neutral.

 

Man sorry to hear about your bad luck. I have a nice black line on my hood where my garage door opener arm grazed it as I was opening the door. Super lucky on my part for sure.

Re. your clutch bleeding issue, do you have the factory service manual? There is a procedure in it for bleeding the hydrualic clutch system. Basically it goes something like this: connect a lenght of tubing to the bleed port and place a container at the end of the tube. Close off bleed port. Pump clutch pedal quickly, about ten cycles will do. Immediately open bleed port to let out trapped air. Do this as many times as required until no air is expelled from the bleed port. I did this by myself and it worked out really well.

 

Finally got the clutch working. I saw a video for a Ranger that had a good idea - disconnect the master cylinder, and point the plunger and reservoir upwards to get air bubbles out. Once I did that, the clutch had a good feel.

Except the truck didn't move - after about a minute and hearing the transmission make noise when in gear, I realized the 4x4 was in neutral, just like Bamba said.

Now big blue rolls again. The ZF542 is a lot different than the M5OD. No doubt that this is a truck.

I also managed to get the cable for the garage door restrung, so the day has ended on a positive note.

Thanks all.

 

Credit should go to Lazy K on the transfer case shift lever position. Glad it all worked out after the bad luck you had with the garage door.

 

Hi PDQ....glad to hear everything finally worked for you. Would you be able to pass on a link to the Ranger video you mention....I am having what sounds like the same problem with my 94 Ranger.

Just replaced the clutch and throw-out bearing, reinstalled everything, dropped the truck off the stands and went to fire it up and the clutch went to the floor on the first push. Second push resulted in the clutch piston rod completely snapping off in the middle. Went back to the parts store and purchased a new master cylinder and installed as per all the instructions. Flushed out the old fluid by bleeding until all air bubbles were gone, fresh clean fluids and up to the top of the reservoir. Now the pedal just goes to the floor like there is no resistance at all....pumped it a hundred times, reblead the line, pushed the throwout bearing back to the slave five or ten times (as per a ford bulletin that came with the new master) and still cannot get anything on the pedal.

Any other suggestions would be greatly appreciated.....

Thanks

Dale

 

Bench bleed it like you would a master cylinder, will work in 5 mins.

 

Hi CJM8515,

Well I ended up pulling the master back out, bench bled it and the pedal pressured up like one would expect. Snapped the quick connect back on the slave and nothing. Bled the slave and then discovered my problem.....argh! The slave was leaking like a sieve. Tore everything back down to the flywheel, popped in a new slave, reassembled for the second time and pow...everything worked fine. Actually better than fine.....most excellent.

Thanks to everyone on this forum for the wealth of info, links, suggestions and helpful tips. It sure has made my life easier the second time around.

Very important lesson learned on this one though.....when you go to all the effort to rip out a tranny to put in a new clutch, spend the extra $100 and put in a new slave at the same time.

To experience that lesson the hard way simply sucks .

Thanks again everyone,

Dale

 

Here's the link to bleeding the master cylinder. Somehow during the time the time the transmission was disconnected (2 days), air leaked through the check valve and got into the master cylinder.

 

Absolutely change the slave when you change the clutch or you will probably be pulling the tranny again. I learned this the hard way and I suspect many others have too. Glad you got it fixed.