Clutch Master Cylinder replacement
 

Does anyone have a DIY for a CMC replacement? I would apprciate any advice.Thank you.

Background:

I purchased the SouthBend Stage 2 clutch/flywheel kit back in 2014.

After having it installed in 2014, I have had issues with the pressure feel of my clutch. I swapped out both clutch master cylinder and clutch slave cylinder.

It feels great in cold weather, but as I drive in stop and go traffic or in the heat, it gets progressively worse. It reaches a point where the pedal only has pressure half way.

When I do a gravity bleed with fresh RBF 600 fluid, the fluid seems to only hold up for about 7000 miles. If its a lower grade fluid, it doesn't seem to last that long.

Joe from zspeed believes it sounds like the clutch master is not holding pressure, replacing it should resolve the issue.

I never did a DIY but I've done it four times now. It's not a difficult install, but there are tight working spaces. For detailed instructions, RJM Performance has an installation PDF for their HD CMC you can find on the product page on their website (the removal part is for OEM, so you can use those steps and then reverse them for the install). Alternatively, paying a competent mechanic should not cost more than an hour or so of labor and may be worth it provided you can get to the shop.

The area around the master is pretty tight fitting. I remove all the surrounding cowls and to give myself as much room as possible. I first suck as much fluid as possible out of the reservoir to limit the amount spillage - brake fluid is nasty stuff so make sure you have lots of towels you can stick down in the engine bay to catch spilling fluid as you disconnect fluid lines. I don't think you have to remove the clutch reservoir itself, but I do in order to give myself more room. Remove the hose and then disconnect the hard line using flare wrench (10mm IIRC). Expect fluid to be spilled during this process. Once you've got the lines disconnected, you'll have to get down in the driver footwell to disconnect the master clevis fork from the clutch pedal as well as the nuts from the master cylinder studs that secure it to the firewall - these nuts can be difficult to get to with the OEM pedal, so you'll need a deep socket (12mm IIRC), extensions, and at least one u-joint swivel adapter (newest RJM pedal provides significantly easier access to them). Once the nuts are removed and the clevis fork disconnected, you should be able to remove the master from the engine bay side. You may have to completely unscrew the clevis fork from the master rod in order for it to clear the firewall opening. You'll have to find just the right angle to be able to remove the master.

I'm with JARblue. I've replaced my MC three times, the last time with the RJM heavy-duty MC coupled to the RJM pedal assembly. I have not written up a DIY, but agree with JARblue that it is a fairly straightforward install. A couple of things:
First, as JARblue points out the space is tight, not only on the engine bay side where the MC is located, but especially in the driver's side footwell where you'll be spending most of your time during the install.
Second, it helps to have a second person involved, not only to steady the new MC when it's first fitted in the fire wall, but also to read out the instructions from either the FSM (stock MC) or RJM PDF (HD MC) while you're stuck in the footwell.
Third, the 12 mm nuts holding the MC against the firewall ... especially the nut on the left-hand side when looking forward from the footwell ... can be difficult to get to. I suggest either a 1/4" drive ratchet fitted with an extension and swivel joint (as JARblue mentioned) or a 12 mm offset wrench. I used the latter.
Fourth, you'll need to disconnect the upper (cruise control) and lower (clutch ignition) switches that are mounted on the pedal assembly. I found these difficult to disconnect simply because of the tight space. The switches will also need to be properly aligned and adjusted during one of the last steps of the install. This can require some patience to get the settings right.
It's also important that the clutch rod be properly aligned so that it moves in and out without resistance when the pedal is depressed and released. I'm still trying to find the absolute "sweet spot" for the adjustment after having driven the car with the new HD MC and RJM pedal assembly for about a week.
Finally, you need to make sure that all moving parts are well greased to avoid rubbing, which can result in annoying noises every time you clutch.
I agree with JARblue that the job could be completed by a competent mechanic within an hour if you're simply installing a replacement OEM MC and staying with the OEM pedal assembly. However, it took me an afternoon to install the RJM HD MC and pedal assembly since it requires more steps ... including removing the fender liner and replacing a portion of the stock clutch line with a braided SS line that is part of the RJM kit.
Trust this helps. Good luck with the install. Final piece of advice: Take your time and read the instructions carefully (at least three times) before beginning the work. Also, if you decide to stay with the OEM MC, you will need to bench bleed it before installing it. You can find instructions for bench bleeding on the internet.

Thanks guys. I just ordered my RJM CMC.

If you don't have it already, get the pedal too! I love the way it feels from the stock POS.

I just had all my clutch parts redone (including clutch plate, pressure plate, and flywheel) and installed the RJM Pedal myself. It was a pretty tight fit, a little frustrating sometimes, but just holding and playing with the RJM vs the oem unit the RJM is a much better piece. It is a little relieving to hear that youve been driving it for a week and are still adjusting, Ive been having a little trouble getting it just right.