How do you bleed the clutch?

[Dorado]

I just did the brakes the old school way between two people: pump and hold pedal, open valve, close valve, pump and hold pedal, open valve, close valve, etc. Back wheels first, then fronts. A clear hose 1/4" ID from HomeDepot was $2. It's a bit tricky to get to the brake fluid reservoir, but it all went well (I needed to remove the top of the air box and disconect a couple of vacuum lines).

Now, how did you guys bleed the line to the clutch, by pumping the clutch pedal too?

The Bentley manual says that you can do the brakes in either of two ways (manual or with pressure bleeder), but they only suggest pressure bleeder for the clutch. The Chilton manual does however say that you can bleed the brake fluid going to the clutch by pumping the clutch pedal, opening the bleed valve, etc. I've been told by a TDI friend that you can't do the clutch by just pumping the pedal.

What gives? Thanks!:)

[kcfoxie]

I'd like to know how to do this too. Say, what brand of fluid are you using for your brake/clutch fluid? It's DOT4 required, correct?

[bugasm99]

there is a nipple on the top of the trans which is similar to that found on the caliper. I will try and either find a pic or take one. It is the same as the breaks but with the clutch pedal.

[Dorado]

Yep, there is a bleed valve nipple at the top of the clutch right beside the fluid line that comes down from the reservoir. So we know where to look... but a pic would help all if you post it. :-)

But, is there any trick to doing it? Pump and hold clutch, open valve let fluid out and close, pump again, etc. Is it supposed to work and feel just like bleeding the brakes?

[Dorado]

I'd like to know how to do this too. Say, what brand of fluid are you using for your brake/clutch fluid? It's DOT4 required, correct?

Yes, DOT4. Bentley says MVSS 116 DOT4. I used ATE Super Blue, recommended by fellow TDI'ers:

http://www.tdiparts.com/catalog/product_info.php?products_id=397

[Dorado]

Here's a post elsewhere that says that you do need a "pressure bleeder" to bleed the clutch line and get new fluid in there:

http://www.jimrothe.com/volvo/clutch_bleeding.htmlClutch Pedal Problems on my Volvo S70

I remember the first time I endeavoured to flush the clutch fluid on my '99 Volvo S70. Volvo calls for this as routine maintenance, and mine was due. I figured "I've bled brakes before... the clutch should be the same principle." Wrong! I must have spent 5 or 6 hours trying to do this, expecting it to be a fifteen minute job with a vacuum bleeder. I could bleed and bleed and bleed all day long, and I did, but no matter what I did, I kept finding that the clutch pedal was to the floor and it would not return to it's starting position with pressure in the system. It had me wondering if perhaps I had damaged the slave cylinder during my attempts at fixing this. At various times during that futile effort, I was truly panicking, as this model year was the first for which Volvo incorporated the slave cylinder and throwout (release) bearing into a single assembly, and it would require dropping the tranny to fix it. That's big bucks or big labor, neither of which I wanted to expend.

After a full day of trying to deal with this "little" job, I gave up when I ran out of daylight. A little web surfing for "clutch bleeding tips" was very revealing. What I found was that many people have had the exact same problems when trying to bleed clutch hydraulics. I found web pages for Porsche, Audi, Volkswagen, Honda, Acura, Saab, Chrysler -- you name it; this is a very common problem. With a very easy solution.

Vacuum bleeders, such as Mityvac and others, remove the fluid that the system counts on to push back on the master cylinder piston, so you end up with a collapsed piston and a clutch pedal to the floor, and no pressure to return them to their starting point. The two man bleeding method often yields the same results. The only reliable method that I was able to find for bleeding clutch fluid is to use a pressure bleeder.

Volvo seems to have one additional peculiarity that I haven't found on any other clutch hydraulic system that I've ever worked on or heard about: if you use a pressure bleeder at anything less than about 20 psi -- or a vacuum bleeder at any pressure -- the master cylinder allows air into the lines. It's as though there's a spring-loaded air bleed valve within the master cylinder that's stays open at any lesser pressure, forcing more air into the system than fluid, and resulting in the collapsed pedal that gave me all the trouble that I described earlier. It was very strange, but the cause and the solution are both repeatable: use low-pressure or vacuum and you'll get no clutch pedal; use higher pressure, and you'll have a pedal. Even after flushing at higher pressure, the pedal is never where it should be (or as firm as it should be) until after about a block of driving, but at least I've found the secret to bleeding this thing. I hope this tip saves you some time![/QUOTE]

[NBTurboFreak]

The Pressure bleeder will help a lot, but is not 100% needed. I have bled mine a few times (I wont leave the tranny alone), all I used was myslef, my rommate, wrench to fit the valve, a catch bottle with hose, and a bottle of extra brake fluid.

It was just like doing the brakes. Pump the clutch 3 times and crack the line. If the pedal stays on the floor when pressed, repeat the process still it does not then do it one more time. Top of the brake fluid and you are done.

This is what has worked for me.