Clutch Pedal Sticky When Cold; Anybody Else?

[Delmed83]

It's been a little cold here in CT. I recently picked up a B5 A4 which is now my daily driver. I decided to take the S4 out for a ride the other day and I noticed my clutch pedal was not returning to its normal position fast enough. It did get better after warming up.

Is this a result of the cold weather increasing the viscosity of the brake fluid? Anybody else get this?

Clutch Slave Cylinder was replaced a couple months ago.......everything was working perfectly after replacement.

[Gujuhammer]

I've noticed that I have to press further down on the pedal to start the car, but nothing like what you describe. My car has been in some frigid temps of late too.

[seanf86]

both my b5 and b6 a4 do this in the cold weather, I'd say its totally normal, b6 has recently had the fluid changed as well as a new master and slave and it still does it, its just the cold weather.

[Smitty2A4]

I have never noticed this in my S4 with RS4 clutch but when its really cold out the gearbox does feel more sluggish until the car warms up so I would say its prob normal.

[Delmed83]

Thanks for replies. Yup, the trans in both the S4 and A4 also feel sluggish until warming up; which I know is totally normal. I just got a little worried about the S because the A4 clutch pedal doesn't seem as sticky when cold.

[rnagy86]

No it's not normal. You either have air in your system or the brake fluid's water content is too high so it ends up freezing a bit (replace brake fluid) or your clutch pedal spring is fucked.

[aysix]

Not sure Dave, my pedal works the same.

[bradthebold]

My Passat would be a little sluggish shifting when it's cold, but my S4 with fluid change shifts the same at any temp. Both never have any clutch stickiness or act any different at any temp.

[audacity]

mine is the same at whatever temperature. i would say flush the system, since brake fluid absorbs moisture it is more than likely freezing up a bit...and fiction and heat from use would generate the heat to loosen it up.

[EuroxS4]

I wanna say that the clutch pedal on my cars feels spongy sometimes,feels harder to press than some other days.So far ive replaced the slave issue is still there once in a while I believe my brake fluid resovoir is leaking at the master and this is the cause of my issue.Or i need to replace the brake booster.

[Delmed83]

My system has all new OEM fluid. I think maybe there may be some air left; though I did bleed the slave excessively when I replaced it.

[JayDee03]

It's simply the cold weather, and very likely nothing wrong with anything else in your car at all. I live in Colorado, have fresh new Motul 5.1 fluid after a complete flush, and my car does this regardless in very cold weather. I have an upgraded aluminum secondary brake cylinder with a stainless steel hose, and stainless steel braided brake lines. With the very narrow brake line going to the secondary cylinder, and the cylinder being outside of the engine bay, the fluid viscosity is going to thicken up in the cold, and take a while to warm up. When this happens at home, I just take my heat gun to the brake fluid reservoir for a minute or two, then pump the brakes, then pump the clutch, and it's fine. It would be great if that line going into the secondary and also the brake fluid reservoir were hooked up to the same system as the washer fluid reservoir, wiper fluid lines, headlight washer pump lines, and the side mirrors so that it would warm up when the temps dropped below 32º F.