G.I.G.

I have an '07 C2S with a manual, and I've read several differing opinions and procedures regarding the proper way to flush and bleed the brake system which includes the clutch slave cylinder on the .1's. From the YouTube videos I've watched and the posts I've read here on Rennlist, it appears that the tools and procedures for performing the brake bleed are fairly straight forward. However, there seems to be differing opinions on how to flush the clutch slave cylinder, so I'm still unclear on the best procedure to flush the old fluid and bleed the clutch.

I've read some posts that state you can flush the fluid from the clutch lines and slave cylinder by pulling old fluid out the reservoir, filling it with new fluid, pumping the clutch pedal a couple dozen times, then repeating the procedure a couple of times. I've also read that you have to bleed the fluid at the slave cylinder itself (which sounds like a bear). Lastly, I've read that it's not necessary to bleed the clutch separately as long as you stay on top of the brake flush/bleed intervals. FWIW, I don't track my car, so this is for routine maintenance (2-year change interval) only.

I want to do it the right way, so any advice or best practices would be greatly appreciated.

cwheeler

my opinion, you dont need to bleed it specifically, I just bleed the brake throughly and dont worry about the slave. It all mixes, so I figure running a full quart of fluid through, it'll get out all the gunk.

G.I.G.

OK, thanks. That was my initial thought as well. Especially if you're up to speed on the change intervals (I'm right at 2 years on the current fill), I can't imagine it's worth the hassle but I'm sure others may not agree with that assessment.

sbbarnett

I always follow the Service Manual, which says to flush at the clutch master cylinder, in similar manner to the brake calipers.

It was difficult to reach the first time I did it, but I ended up bending an open end wrench, and that made it much easier.

Carreralicious

3 years ago I had my dealer bleed the clutch slave because I noticed once that when I pressed the clutch down, it only came back up halfway. After they bled it, I haven’t had the problem come back.

Petza914

Bleed the clutch at the slave. This rig works great as you can loosen then tighten the bleeder screw without removing the tool and the fluid goes through the hose and into a collection bag, so no mess. Any Max Axess type socket set should work.

G.I.G.

That's a cool setup. Did you buy that or have to make it custom? I'm never apposed to buying tools

Petza914

It's just the small ratchet and extension from my Craftsman MaxAxess socket set with silicone bleeder hose and collection bag from speedbleeders

G.I.G.

OK, thanks. I miss Sears/Craftsman. I'll swing by Harbor Freight in the next few days to see if I can find a similar socket set.

Petza914

Don't see that HF offers this type. Lowe's and Home Depot both do, and this one on Amazon
FIRSTINFO Low Profile Go-Through Socket Wrench 52 Pcs Set, 1/4" 3/8" 1/2" Wrench, Spline Sockets For Damaged Fasteners
looks good with 3 different handle sizes. You want a smaller one to get into that area.

eBay has a bunch of Craftsman ones too - much higher prices than when I bought mine from Sears years ago.

G.I.G.

For those of you who have tackled the clutch slave cylinder flush/bleed themselves, I have two remaining questions:

1) Can you perform the slave cylinder bleed by removing the rear wheel and having the car up on jack stands only, or does this require a lift in order to get access?
2) Do you need to remove the rear most plastic under tray to access the bleed valve, or can you leave that in place if you remove the rear driver's side wheel?

I ask because I'm wondering if I can try to tackle this over the holiday weekend at home with a jack and jack stands by myself, or if I should wait until I can use a friend's lift.

andino

It can be done without a lift however I did mine on a lift. I only needed to remove the rearmost plastic undertray to get access to the trans and slave cylinder. I used a pressure bleeder at the reservoir but still needed a friend to pump the pedal in order to get fluid out. I had my bleeder set around 20psi or so.

G.I.G.

Good to know, thanks.

G.I.G.

OK, I've purchased a power bleeder, catch bottles and tubes, as well as a pass-through socket set thanks to the pro tip from @Petza914, so I'm ready to tackle this project. After watching some YouTube videos and reading through this thread and others, I have one remaining question: If I were to do the "dry method" (using the power bleeder to pressurize the system only) and do not fill the power bleeder with fluid, will I have to stop mid-bleed to refill the reservoir? I know I will need to get as much of the old fluid out with a turkey baster first, then fill the reservoir to the top with new fluid. However, the line going from the reservoir to the clutch slave cylinder is at the top of the reservoir, and I don't want to get air into the system. It seems as though you would only be able to get a handful of ounces through the line before the fluid level in the reservoir would drop below the clutch line, allowing air into the system. So can I use the power bleeder dry, or will I need to fill the power bleeder with fluid in order to keep air out of the system?

andino

If you're just doing a bleed, then you'll likely be fine with a full reservoir. Just top it off at the end after bleeding. If you're doing a flush, then you'll need to top off midway. Not sure which bleeder you got but hopefully it has a valve and disconnect so you don't need to release/repump each time you top off. Otherwise, you'll have the small inconvenience of having to do that song and dance but it beats cleaning fluid out of the bleeder tank imo.

edit: I recommend placing a flashlight on the top of the tank facing inside so you can easily see the fluid level as you're working. There's a small hole in the plastic panel to view the level if you're not removing it.