CDV Delete e89 2009+

[tintoverano]

I saw many posts and videos, but each was lacking some details here and there, hence a How To (not being a mechanic, as most of us, this may help other newbies like myself)

the result: reading some of the excited posts I was sceptic about the potential impact, I mean it couldn't be that good/bad - I have to confirm my mates, I got a brand new clutch experience now and it is mighty good

today is the 2nd day after the mod, I did a hilly test drive (wanted to cool down) - the difference is literally shocking, therefore I couldn't


the steps

0. have a friend around who can help with the second part (bleeding) - though you won't need her if you did it again for some reason

1. get 0.5 litre DOT4 brake fluid and fill the reservoir above max (there's gonna be spillage for sure, but don't worry)

2. lift the car (jacking up only will make you suffer along the way) - wear gloves, glasses to protect yourself

3. remove two bottom engine covers to find your CDV:

CDV position

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4. before removing the factory installed valve apply a hose pinch

• this will do, nothing fancy https://www.kingtony.com/product_detail ... 1&Key=1502

  

  hose pinch

  hose pinch.jpg (87.53 KiB) Viewed 5230 times

  so you don't lose much brake fluid after disconnecting the hose and the valve

  

  hose pinch position

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  5. the valve is locked in by two push ring locks at both ends of it

  

  push ring locks & bleeder position

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  6. pull up the ring locks, use e.g. a screwdriver, to release the valve ends and remove the valve
  
  7. insert the new valve
  • I bought a modified valve: https://www.sound-pressure.de/BMW-Dross ... 1526765120, some say you don't need it and just connect the hose back
  first insert the right side of the valve, push hard and then connect the hose (with the pinch still applied) on the left side of the valve, push hard again and use the lock rings to secure the new valve
  
  8. remove the hose pinch and you must bleed the clutch circuit now to get rid of the air, which got stuck inside

  

  bleeder with rubber cap

  Screenshot 2019-04-19 at 18.09.33.png (1.21 MiB) Viewed 5230 times

  9. remove the rubber cap from the bleeder (see above) and connect the vacuum bleeder
  • I went for this one https://lincos.tools/2926-vacuum-pressure-test-kit.html
  and do the same as the video shows
  
  it will be harder though, since the car is higher up, and you need to hold the pump, pump it and open the bleeder screw at the sam time - the need for a friend
  
  10. wipe the valve clean with a rug, so you can see if there's any leakage, after doing the next step
  
  11. lower your car until you can reach the clutch pedal with your hand, then start pumping it 5-10 times, check its stiffness
  • if it seems OK, lift up your car, check the valve for leakage and put back everything, because you're ready with the CDV Delete
  • if it doesn't feel OK, e.g. the pedal doesn't come back up or you hear the sound of spillage, look under the car for fluid and check if you connected the hose and the valve the right way and repeat the steps till the pedal is stiff and there's no brake fluid leakage
  • start with re-filling the reservoir above max
  12. when your car is down check the brake fluid level in the reservoir - there's a sensor, but it doesn't hurt to see it with your own eyes

[flybobbie]

Good idea also to fit a braided hose, they come with the push fittings. I was tempted to bypass the squiggly pipe, but left it in place. And for bleeding just let it sit with the valve open for 5 minutes into a jar, you will find it bleeds ok.

[tintoverano]

I see, thanks for the bleeding tip

[TDJ Stefan]

Hey,
Nice writeup. Did this recently to mine with the BMS CDV and what a diffrence it made. Didn´t expect it would do that much. And not only can you actually feel what the clutch is doing, the entire gearbox feels better somehow.
As for the bleeding, i just left it with a hose and a bottle for a couple of minutes and it worked fine for me so it obviously works

[tintoverano]

Hey,
And not only can you actually feel what the clutch is doing, the entire gearbox feels better somehow.

thanks for confirming that I'm not just imagining it

[TheThingIs]

excuse my numbness but is this for manual or auto transmission?

[Jembo]

Manual only

I also though this only affected E85/6... learn something new everyday

[tintoverano]

excuse my numbness but is this for manual or auto transmission?

manual only

[TDJ Stefan]

Manual only

I also though this only affected E85/6... learn something new everyday

This can be applied to basically any car, I´m just amazed how big a diffrence it made to my car

[Broads]

I've seen this mentioned a few times now, and what does it actually do?
I assume it allows for a quicker change between 1st and 2nd cause for some reason that always seems clunky!


What is the purpose of the valve, as I assume it is there normally to perform some function.

[tintoverano]

A Clutch Delay Valve (CDV) is a one-way restrictor, located between the clutch slave and clutch master cylinders. It slows the engagement of the clutch, similar to a damped record player tone-arm, gently lowering the needle to the surface of a record.

https://www.zeckhausen.com/catalog/index.php?cPath=6562