Sticking clutch pedal rs4 b7

[JamesBaby]

It's not the 5.1 spec you need. The regular DOT4 will be fine. What resolves the problem is a "Clutch Fluid Change". Most people don't know that the factory manual for a brake fluid change FIRST requires you to change the fluid in the Clutch Slave Cylinder THEN the brakes. Most workshops just bleed the brakes. Thus after 17 years the fluid in the clutch slave may as well be water.

The clutch slave is a pig to access but it is done from underneath by removing the heat shield above the NSF driveshaft. This allows you to reach up with a small tool and loosen the slave cylinder bleed screw.

Process: Empty the fluid reservoir and pour in fresh brake fluid first. That way fresh fluid is sucked into the slave cylinder in the process. Press the clutch a few times. open the bleeder and allow some fluid out. Then close it and pump pedal again, and re-bleed. Do it 2-3 times at least. Then proceed with brake fluid change.

[axnjaksn]

Before you spend big bucks, change the clutch fluid to Dot 5.1 (higher boiling point). I had exactly the same problem, changed several mechanical parts to no avail. Fluid solved it immediately and permanently. Have pointed this out on several occasions here but no-one seems to listen!

ok dude ive seen you mention this a lot....i have all new clutch parts and still have the same issue....is this really going to resolve it??? i have endless rf650 fluid which is supposedly better specs than anything these days

All I can say is I read about the same issue with another car in evo and tried it myself. It worked, and I have not had a single instance of it happening again since - ever - and that's most of the 18 years I've had the car for. That's not a guarantee that it'll work for you, but I'd suggest it's worth a try.

If you do try it, report your findings here - for better or worse.

I most definitely will and I have bleed my clutch by itself twice within the last 6 months and have replaced the master, the feed line and the slave is usp Motorsports with the stainless line that was installed a few years back, if even that with new clutch and pressure plate and lwfw. So I’m literally running on nothing else could be causing this, I have noticed since I started bleeding the fluid it’s gotten funny, pedal be normal and stiff - normal and feels softer, the pedal sticking when I’m on it hard, not sticking when I drive aggressive but not WOT, it’s all over the place. So I’m at my wits end - I even wrapped my slave and most of the line with heat shielding - I have also bled the brakes 3 times since I’ve owned the car which is 5/6 years….so km ahead of schedule on that as well. Will post results - hopefully in the next few weeks, would like to have it done today or tomorrow but I’m having a hard time making the time at the moment. My luck tho, it will be something else like the brake master cylinder or a check valve in the pcv/vacuum feed to the brakes, or something ridiculous (Murphy’s Law with me) - anyways cheers and thanks for the pep talk

[axnjaksn]

It's not the 5.1 spec you need. The regular DOT4 will be fine. What resolves the problem is a "Clutch Fluid Change". Most people don't know that the factory manual for a brake fluid change FIRST requires you to change the fluid in the Clutch Slave Cylinder THEN the brakes. Most workshops just bleed the brakes. Thus after 17 years the fluid in the clutch slave may as well be water.

The clutch slave is a pig to access but it is done from underneath by removing the heat shield above the NSF driveshaft. This allows you to reach up with a small tool and loosen the slave cylinder bleed screw.

Process: Empty the fluid reservoir and pour in fresh brake fluid first. That way fresh fluid is sucked into the slave cylinder in the process. Press the clutch a few times. open the bleeder and allow some fluid out. Then close it and pump pedal again, and re-bleed. Do it 2-3 times at least. Then proceed with brake fluid change.

This has en done by me several times since I purchased the car and seems like it’s only gotten worse or had no effect - one or the other I’d say, which is why I’ve replaced all the parts. That’s and the age of the vehicle and also the fact that the car has 220k miles on it - better fluid is my next step and I’ve seen 12th post a lot about it and he’s right, it’s worth trying c easiest and least costly repair for sure. Either way I’ll find out here soon haha

[12th]

ok dude ive seen you mention this a lot....i have all new clutch parts and still have the same issue....is this really going to resolve it??? i have endless rf650 fluid which is supposedly better specs than anything these days

All I can say is I read about the same issue with another car in evo and tried it myself. It worked, and I have not had a single instance of it happening again since - ever - and that's most of the 18 years I've had the car for. That's not a guarantee that it'll work for you, but I'd suggest it's worth a try.

If you do try it, report your findings here - for better or worse.

I most definitely will and I have bleed my clutch by itself twice within the last 6 months and have replaced the master, the feed line and the slave is usp Motorsports with the stainless line that was installed a few years back, if even that with new clutch and pressure plate and lwfw. So I’m literally running on nothing else could be causing this, I have noticed since I started bleeding the fluid it’s gotten funny, pedal be normal and stiff - normal and feels softer, the pedal sticking when I’m on it hard, not sticking when I drive aggressive but not WOT, it’s all over the place. So I’m at my wits end - I even wrapped my slave and most of the line with heat shielding - I have also bled the brakes 3 times since I’ve owned the car which is 5/6 years….so km ahead of schedule on that as well. Will post results - hopefully in the next few weeks, would like to have it done today or tomorrow but I’m having a hard time making the time at the moment. My luck tho, it will be something else like the brake master cylinder or a check valve in the pcv/vacuum feed to the brakes, or something ridiculous (Murphy’s Law with me) - anyways cheers and thanks for the pep talk

Yours definitely sounds more complex than most - I hope it helps and you've nothing to lose, I guess.

Finges crossed for you.

[axnjaksn]

Ok dudes, just bled 3
Bottles of endless rf650 through the vehicle, clutch bleeder first, then in proper order of farthest to closest using a pressure bleeder, see what happens - post updates later lol

[JamesBaby]

That’s not the correct order of bleeding. You start with Front Left, then Front Right, then Rear Left, then Rear Right.

Brake_Fluid.pdf

(868.21 KiB) Downloaded 69 times

[axnjaksn]

And there we have it, pedal felt great the whole drive home from work, however I WOT a 2-3 and a 1-2 and it stuck again. The new fluid feels great but wtf is causing this!! The metal usp slave is the oldest thing in there now….and not that old l- but what else

[axnjaksn]

Any of you guys out there have the USP Motorsports stainless line and metal slave?? Just curious . Oem style clutch and op with the SAC??

[12th]

Ah - really sorry it didn't work in your case.

[axnjaksn]

It’s all good. I feel better having top notch fluid in there at least

[RS4Guy]

Hey Dritsy, you'll probably find that the clutch pedal is sticking because the clutch master cylinder is damaged and will need replacing too. I managed to get one from Autodoc.