Good morning. I have a 2011 Ranger XL extended cab 4.0l 5spd 4WD. There are 248k miles on the odometer.

The clutch began to slip and burn up earlier this year so I ordered new parts - flywheel (Luk LFW382), clutch kit (SPEC SF673H Stage 2), Slave cylinder (Perfection PFT-360016) figuring that going back with new parts would be the easiest way to deal with it. At this time I didn't plan to replace the clutch master cylinder since there was no issue with the clutch pedal travel or shifting. The plan was to disconnect from the slave cylinder and reconnect after new parts were installed and then drive away. It did not work that way so far.

These parts would be replacing a Luk 07167 clutch kit installed in 2021 with almost 10k miles on it. That is not many miles. I installed this clutch in 2021 after getting only 2k miles on another clutch set that I installed when I had the transmission rebuilt. Basically burned up two clutches in 12k miles since buying this vehicle. Both clutches were OEM replacements so this time around I decided that I needed better disk engagement so I went with a Stage 2 clutch from SPEC. I have a tendency to lay down on the foot feed and lunge on leaving lights and this truck is not fast. I probably burned those two clutches with my driving style.

I pulled the transmission the first week of May and had it back together after delays for miscellaneous parts (flywheel bolts and pilot bearing) about two weeks later. When I attempted to reconnect the CMC (clutch master cylinder) to the CSC (clutch slave cylinder) so I could check the it all out I had a hard time getting the old CMC into the new CSC end but they finally lined up and clicked together so that was good.

My problems had just begun though. The transmission would not shift into gear so I determined that there was probably air in one part of the system that needed to be bled. I had assumed that the CMC was purged since I had great pedal before replacing all those parts but found that I could no longer shift. I started off by bleeding the CSC at the bleed port. I thought I was in luck when I cracked the bleeder and several bubbles zipped into the hose. I bled at the CSC bleeder several passes until there was no air and made sure that the master cylinder did not run dry. Still no pedal.

Next I worked on burping the CMC. I tried various methods to get the air out including leaving it in the truck but pulling the CMC from the firewall and orienting it and the rest of the master cylinder lines so that bubbles could travel up and out. I used my MityVac to pull a vacuum at the master cylinder and managed to pull several bubbles with the vacuum at 23 psi. After numerous fruitless attempts I decided to remove the CMC from the truck and follow the guidelines that you see illustrated in the videos from Perfection Clutch.

This is where I ran into a problem. When I was disconnecting the CMC from the CSC, I initially couldn't separate the two but after wiggling and pulling awkwardly in the tight space available I managed to get them to break loose. They did not come apart though. To my chagrin I discovered that there was an o-ring holding the two together. It was trapped in the check valves of the two parts as you can see in the photo that I took at the time because I knew right away that this was a bad thing that I would need to remember.



Disconnecting the CMC from the CSC. There is an O-ring trapped in the check valves that was preventing them from separating.

I pulled gently on the CMC line until the two separated and that is when I could clearly see the problem.



The O-ring came off with the clutch master cylinder line.

You can see that it is trapped in the CMC check valve. I do not know whether the O-ring belongs on the CMC side or the CSC side. Big problem.



O-ring is clearly caught in the check valve. Which side does it belong to and how do I get it back in place? Hmmmm.

You can see that the wiggling to make the connection has scratched through the anodized surface on this end.



Scratched up mating surface due to wiggling the connector to get it together on reassembly. Has anyone ever seen anything like this?

At this point I had decided that the CMC was never gonna burp so I had ordered a new clutch master cylinder from Ford Parts Giant (7L5Z-7A543-B) and since it didn't come with a rod I ordered one from RockAuto (SKP SKCM640006) and did not run through the Perfection Clutch process to bleed the new master cylinder because it claimed to be ready to install, pre-bled. I installed and connected it to the CSC with no issues at all. Clicked right in place.

This new CMC did not solve the shifting problem. I was still unable to get the truck into gear. I ran through the Perfection Clutch process, removing the CMC and taping it to a board after stretching the line so that any air had an uphill path all the way. I tapped bubbles out of the line using a screwdriver handle and pumping the plunger repeatedly. I did not get many bubbles and all were small so I put my MityVac on the CMC and pulled a vacuum again and with that setup was able to get some larger bubbles and a stream of small bubbles. Once those faded to nothing, using a screwdriver to tap the lines and working the plunger while keeping the fluid topped off, I capped the CMC reservoir and let it all sit overnight so it could gravity feed any other bubbles up to the reservoir.

I checked the fluid levels this morning and found it full. I tapped the lines again for several long minutes but did not get any bubbles. I pulled a vacuum again, 20 psi, but still did not get any bubbles while tapping for nearly 30 minutes. I decided that the air was purged so I took the CMC to the truck and installed it. No issues making connections or anything.

After all that I still cannot shift into gear.

Any ideas? There is a 50% chance that the O-ring that you see in the CMC check valve came from the CSC check valve. That would mean that I either figure a way to replace it without dropping the transmission or I bite the bullet and drop the transmission and replace the whole CSC.

Am I the only one on earth lucky enough to have this problem?

These last photos show the Stage 2 clutch installed and aligned before sliding the transmission in place and bolting it all together.



New flywheel Luk LFW382



New Stage 2 clutch disk - SPEC SF673H



New pressure plate Stage 2 clutch kit - SPEC SF673H



Ready to stab transmission and bolt it all up.

Any ideas are welcome. Thanks for reading this far.

 

Just for clarity - does the transmission shift in to gear when the engine is not running? You didn't say in your post. Maybe it's a shift linkage problem. I got mine messed up when I pulled my shifter once and had to use a screwdriver to get things realigned correctly. It's a thing.

That o-ring looks like it belongs in the slave cylinder fitting. You can browse the pictures on Rock Auto and see it.

https://www.rockauto.com/en/catalog/ford

 

Yes, the transmission can be shifted into any gear while the engine is not running. Once the engine is running though the clutch will not release so if you start the engine with the transmission in gear you risk a rolling start even with the clutch fully depressed. I drove it around the yard after starting the engine with the transmission in reverse so I could back up, then killing the engine and shifting to 2nd gear and starting the engine. It will not shift into another gear once it is rolling with the engine running though I didn't take it onto the highway to test speed-shifting.

I have watched the Perfection Clutch videos that break down each of their components and how to install, bleed, etc the systems. The o-ring that you see in the photos on RockAuto would be used during reassembly to replace the existing o-ring on the master cylinder side connector if you were reusing the master cylinder and the existing o-ring on the male end needed replacement. They also include a spare plastic split ring in case the existing one is damaged during disassembly. The o-ring in my disassembly photos that is trapped in the check valve is not the same cross-section or OD as the o-ring that seals the master cylinder to the slave cylinder. That o-ring had to be inside the slave cylinder or part of the master cylinder when i tried to make the connection and ended up needing to wiggle things together to force the connection resulting in the damage to the anodized area that is seen in the photos.

Since I have all the old parts and other photos of new parts I think I can show where it all fits in normal operation.

Outline of master cylinder connector seals, etc using new assembly from Ford Parts Giant

I went out and removed the trapped o-ring from the old master cylinder assembly so that I could see where it would fit. It turns out that it seals the master cylinder check valve connection.



Clutch master cylinder replaced due to o-ring trapped in check valve

I used a pick and phillips screwdriver to release the o-ring from the check valve. I held the pick between my knees and held the fitting steady with one hand while depressing the check valve with the end of the screwdriver until the o-ring popped loose. This left the check valve open and off center inside the fitting. The old o-ring is visible on the cardboard.


master cylinder fitting after removing the snagged o-ring. The check valve is open and off-center.



Problem O-ring with the master cylinder fitting as it ended up after removing the o-ring.

I centered the check valve using a screwdriver so that I could test whether this connection seals without the o-ring.


Problem o-ring and master cylinder fitting after centering the check valve in the fitting.

I tested the seal by working the plunger on the master cylinder. As you can see it sprayed fluid past the master cylinder fitting check valve confirming that the o-ring in the photos is supposed to seal that check valve.


Master cylinder fitting after exercising the master cylinder plunger rod to test the check valve seal. It produced a spray from the check valve confirming that the o-ring was supposed to seal this check valve.


I guess the next question is whether I can match the o-ring and replace it and end up with a sealed master cylinder assembly suitably trustworthy for road use.

Interesting question.

 

Looks like you have a mess on your hands. Did you buy from a parts store, like O'Reilly's? I'd take it back as defective and let them swap you a new one.

Is this the video you watched? You took the hydraulics completely off?

 

That is one of the videos that I have watched. I watched all of the videos on RockAuto's page for the clutch slave cylinder from Perfection Clutch.

https://www.rockauto.com/en/moreinfo...t=2044&jsn=722

There are lots of others from various techs or shops demonstrating other methods of bleeding including pumping the pedal, vacuum bleeding, etc. I watched lots of things and tried to follow them all. It's a process of elimination to find the one that works. So far I need another video. LOL.

I think I bought the master cylinder assemblies from RockAuto, though I know I checked Summit Racing, Ford Parts Giant, Autozone, and OReilly Auto Parts. I would have to check receipts to know for sure but I am way past return deadlines on this since I had to wait for an opportunity to install all this after the parts arrived and had further delays as I found wear parts that I also considered end of life and needing replacement so I had to wait for those parts to be delivered.

I did bench bleed and also tried bleeding while it was installed in the vehicle after contorting things to remove air traps as much as possible.

 

I don't know if it would work the same on the clutches as on brakes but if the problem is air in the system you should be able to pump the pedal and get the slave to work. Maybe. The pressure plate springs might push the fluid back too quickly.

If you decide to get a hardware store o-ring make sure it will handle brake fluid.

https://www.pegasusautoracing.com/do...0brake%20fluid.

 

Thank you for that link. I have a link somewhere among the thousands to an O-Ring supplier site with that information but I would waste lots of time finding it in my disorganized bookmarks. I went to my o-ring collection and located one that is a close match to the check valve o-ring. I just need to find my calipers to cross-check so I can know that I am close or maybe I should call Perfection Clutch to get the correct specs.

I think I can slide one on the shaft of a screwdriver and depress the check valve with the screwdriver so that while I am depressing the check valve I can use a soft plastic tool to slide the o-ring past the shoulders onto the check valve and hopefully into the o-ring groove. If I can do that I will do a bench bleed test to see whether it holds pressure. There appears to be no reason why it wouldn't so this might be useful to keep as a backup clutch master cylinder. I've already tested the first part of the process but just need to find a non-marring tool to ease the o-ring past the check valve.