Jump to content
SAU Community

Vacuum noise INSIDE car when clutch depressed?

xfixiate
 Share

Recommended Posts

xfixiate Rising Star

xfixiate

Posted
Posted

My skyline has just developed what sounds like a Vacuum leak when the clutch is depressed.

It's definitely inside the car near the top of the clutch pedal. Occurs when the clutch is touched and depressed. Car idle changes.

I looked inside and outside but can't see any clutch vacuum assist hoses. Doesnt' make noise outside the car that I can tell.

Clutch is now harder to use, but still works.

Any clues on what it might be?

NZM.031 Grand Master

NZM.031

Posted
Posted

i had the same problem on the weekend. turned out my boost guage line had slipped out of its cable tie and snuck down to my clutch pedal.... noticed the clutch was harder than usual, then next time i pressed the clutch it pulled it off the guage.... made alot of vacuum noise then

haha, my bad

cheers

Linton

wrxhoon Grand Master

wrxhoon

Posted
Posted
Vacuum booster? On clutch?

Maybe the throwout bearing is worn mate. Gearbox out to replace, but get a mechanic to have a look. It's hard to diagnose from the couch :cheers:

Yes the gtr has a booster for the clutch , sounds like the diafragm is leaking /stuffed so he can hear the noise and his pedal is harder , more effort without assistance .

xfixiate Rising Star

xfixiate

Posted
  • Author
Posted

It's not the throw bearing - you'd hear that underneath.

Defintely a vacuum noise.

Clutch is stiffer to operate (right through movement), and there is no "take up" noise as you'd expect with a buggred throw.

It's weird. I thought perhaps there might be a hose there somewhere.

Vacuum booster? On clutch?

Maybe the throwout bearing is worn mate. Gearbox out to replace, but get a mechanic to have a look. It's hard to diagnose from the couch :cheers:

xfixiate Rising Star

xfixiate

Posted
  • Author
Posted
Yes the gtr has a booster for the clutch , sounds like the diafragm is leaking /stuffed so he can hear the noise and his pedal is harder , more effort without assistance .

Where's the vacuum take off? I can't see it from up top..

GTRgeoff Grand Master

GTRgeoff

Posted
Posted
Yes the gtr has a booster for the clutch , sounds like the diafragm is leaking /stuffed so he can hear the noise and his pedal is harder , more effort without assistance .

:cheers: I didn't know that.

wrxhoon Grand Master

wrxhoon

Posted
Posted
Where's the vacuum take off? I can't  see it from up top..

Have a look inside the engine bay , next to your brake booster . There is the clutch master cilinder and a very small booster , thats the one .

The diafragm inside the booster maybe stuffed or the hose going to it came off /broken .

Geoff do you have a 33 gtr ? Have a look in the engine bay .

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Kapr
      RB20DE NEO smallbox clutch.

      By Kapr · Posted

      For once a good news  It needed to be adjusted by that one nut and it is ok  At least something was easy But thank you very much for help. But a small issue is now(gearbox) that when the car is stationary you can hear "clinking" from gearbox so some of the bearing is 100% not that happy... It goes away once you push clutch so it is 100% gearbox. Just if you know...what that bearing could be? It sounding like "spun bearing" but it is louder.
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      Yeah, that's fine**. But the numbers you came up with are just wrong. Try it for yourself. Put in any voltage from the possible range and see what result you get. You get nonsense. ** When I say "fine", I mean, it's still shit. The very simple linear formula (slope & intercept) is shit for a sensor with a non-linear response. This is the curve, from your data above. Look at the CURVE! It's only really linear between about 30 and 90 °C. And if you used only that range to define a curve, it would be great. But you would go more and more wrong as you went to higher temps. And that is why the slope & intercept found when you use 50 and 150 as the end points is so bad halfway between those points. The real curve is a long way below the linear curve which just zips straight between the end points, like this one. You could probably use the same slope and a lower intercept, to move that straight line down, and spread the error out. But you would 5-10°C off in a lot of places. You'd need to say what temperature range you really wanted to be most right - say, 100 to 130, and plop the line closest to teh real curve in that region, which would make it quite wrong down at the lower temperatures. Let me just say that HPTuners are not being realistic in only allowing for a simple linear curve. 
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      I feel I should re-iterate. The above picture is the only option available in the software and the blurb from HP Tuners I quoted earlier is the only way to add data to it and that's the description they offer as to how to figure it out. The only fields available is the blank box after (Input/ ) and the box right before = Output. Those are the only numbers that can be entered.
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      No, your formula is arse backwards. Mine is totally different to yours, and is the one I said was bang on at 50 and 150. I'll put your data into Excel (actually it already is, chart it and fit a linear fit to it, aiming to make it evenly wrong across the whole span. But not now. Other things to do first.
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      God damnit. The only option I actually have in the software is the one that is screenshotted. I am glad that I at least got it right... for those two points. Would it actually change anything if I chose/used 80C and 120C as the two points instead? My brain wants to imagine the formula put into HPtuners would be the same equation, otherwise none of this makes sense to me, unless: 1) The formula you put into VCM Scanner/HPTuners is always linear 2) The two points/input pairs are only arbitrary to choose (as the documentation implies) IF the actual scaling of the sensor is linear. then 3) If the scaling is not linear, the two points you choose matter a great deal, because the formula will draw a line between those two points only.
×
×
  • Create New...