Some how it completely escaped me that all the after market options for the clutch master cylinder did not include the hardline connector on the cylinder.

is it feasible to reuse the connector on the old MC? It has a u pin that can be pulled.

We are working on the clutch system. We have successfully installed the new flywheel, pilot bearing, clutch, fork, throw out bearing, etc and had both the mc and sc hanging, all lines connected, going to swap out quickly to minimize fluid loss when we saw the missing connector.

a parts search shows that this seems to be common.

can we reuse the original connector on the old mc?

 

It looks like that's the intent - pull the U pin, unplug, probably replace the O-ring on the flare adapter, plug in to the replacement MC, install the U-pin. Honda has separate part numbers for the line adapter (same part on both the MC and SC), U clip, spring pins (found on the SC in place of the U-clip), MC and SC O-rings (looks like maybe X-rings?), so they definitely intended that those parts be disassembled.

 

thanks.Got that completed this morning. Ended up having to tap the holes. They weren’t the right size. We tapped them out to just fit the pin snugly, then set the tip on the one side to prevent slippage. But it’s so snug that I don’t think it will work its way out.

Now we have another problem. We can’t seem to get the master cylinder past the power assist and strut well. We've been playing with it all day.

 

I’m almost to the point where I’m willing to dent the nub sticking out from the strut well wall just to get the fitting is slide .

Only thing holding me back is the possibility that there will be something else in the way

 

Are you installing a MC designed for a different car? If it's the same size and shape, the replacement should go in the same way it came out.

 

its an after market cmc, but its for the 3rd gen honda fit

this is Honda we’re talking about. They have a habit of hiding cmc behind the strut well in a way where it’s extremely difficult, at best, to replace. Some models actually require that the brake booster and brake mc be removed to get to the cmc.

I did find that the bolts on the triangular plate have a higher profile than the original clutch and I swapped those. It’s better but still slightly off.

I’m considering drilling to make the holes through the firewall slightly larger to get the clearance I’m still missing. The clutch bracket should keep the cmc stability in check.

 

You said you swapped out the bolts? Can you take the bolts out, slide the MC in place, then slide the bolts through the MC hole into the firewall hole?

 

i don’t think i would have the clearance to appropriately tighten them afterwards and after messing with it as long as I have, I think the bolts no longer got like they used to but the hardline connector is now in the way. There’s no way I could assemble that after installation.

 

After more struggling I decided to measure absolutely everything.

The posts/bolts/studs on the aftermarket cmc are set just a little wider apart than the original.
So it looks like I have to order from Honda. I’m hoping to find a dealership in driving distance that has one in stock. I really need to get this thing running by Wednesday to avoid having to rent a vehicle.

 

Closest dealership with part in stock is 3k miles away.

Everything is being ordered overnight. I hope this resolves the spacing issues.

We decided to try to return the cmc/csc to the online vendor. But we will wait.

After talking to the main mechanic at the shop we just decided to order the cmc, csc, and pilot bearing from dealer and hope that the after market flywheel, friction plate, pressure plate, and throw out bearing will be ok.

 

🤞

Question: Was the CMC bad? Sinking pedal? External leakage?

 

sinking pedal and 299k miles

and when we removed the clutch, the friction plate was bad

 

Alright, so it had a good run.

 

We finally got everything in and running again.

honda cmc went in so much easier.

Aftermarket friction plate was a pita. Had to clean burrs from the grooves.

Clutch is much easier, goes into great much better.

Would be awesome if we manage to get another 200k miles out of it.

 

That ejected spring dragging on stuff will do that.

How-your-transmission-works text wall:
Each gear has a "synchro" (short for synchromesh) next to it that rev-matches the two halves of the gear you're tying to select. The synchro doing its job is what creates that brief resistance in pushing the shifter into a gear. When the two halves of the gear are going the same speed, they lock together and the shifter drops into position.
In reality, the teeth of all the gear-pairs (one pair of gears for each transmission speed) are constantly in-mesh (except for reverse which is a triplet of gears, the middle one actually does slide along a shaft into position). One gear of each forward-speed pair is locked to its shaft, the other has the synchro mechanism to let it freewheel (not selected) or lock it to its shaft (in gear). Point being, the synchros are also rev-matching two shafts in the transmission.
The shaft with the clutch disk on it is called the input shaft or main shaft, which also has one half of each selectable gear-pair on it. There's a shaft running parallel to it with the other half of the gear-pairs on it, called the counter shaft. The counter shaft also has one half of the "final drive" (seen on vehicle spec sheets) gear pair on it, the other half is on the differential, which sits next to the counter shaft. The differential spins the driveshafts, which spin the front wheels, so the speed of the differential depends on how fast the car is going. The final drive gear pair (which is always connected, no shifting mechanism involved) similarly makes the counter shaft's speed depend on vehicle speed. That leaves just the input shaft that can free-spin to rev match. It's only actually free to spin when the transmission is in neutral (no gears selected) and when the clutch is disengaged (pedal pressed). When the clutch is engaged, the input shaft is locked to the crankshaft of the engine.

On topic: That loose spring was creating drag between the clutch disk (attached to the input shaft) and the flywheel/pressure-plate (attached to the engine crankshaft). That resulted in the clutch never fully disengaging, meaning the input shaft wasn't quite free to rev-match. That made the synchro's job very difficult, as it was trying to make the counter shaft's speed (which depends on vehicle speed, meaning it has the whole car's momentum behind it) match the input shaft's speed, which now has the momentum of the flywheel and crankshaft dragging it along.
It doesn't surprise me that it took some extra time and force (not good for the synchros btw) to overcome the engine drag. Though actively trying to rev-match the engine to whatever gear you're shifting into (just like when trying to drive with no clutch) should have helped. Good to hear you got it sorted.