[Z06] mushy clutch pedal after hard driving
#21
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I use Prestone DOT4, widely available including Walmart, for about $2.60 for 12 oz.
Keep changing the fluid after each drive until the fluid stays clear.
If the fluid has never been maintained through its long life to now, the master cylinder seals may be abraded by accumulated clutch dust. I wouldn't conclude that is the case until the fluid is rendered to pristine condition.
Ranger
Keep changing the fluid after each drive until the fluid stays clear.
If the fluid has never been maintained through its long life to now, the master cylinder seals may be abraded by accumulated clutch dust. I wouldn't conclude that is the case until the fluid is rendered to pristine condition.
Ranger
#22
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In the meantime until the fluid is rendered back to pristine condition, you want to avoid high-rpm strong shifts. Pedal issues lead to tranny issues, if the clutch isn't releasing properly.
Good luck and let us know how it turns out.
Ranger
#23
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What is the torque handling capacity of the Act dual disc clutch?
What is the max torque your engine produces in its current configuration?
BTW, the disengagement issue is a classic pedal symptom whose root causes include:
(1) corrupt clutch fluid
(2) damaged master cylinder seals from abrasion by accumulated clutch dust in the fluid
(3) inadequately sized clutch for installed engine power
Ranger
#24
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Ranger,
Is it worth getting the tick master cylinder for 300 bux or should I just stick with a new stock master cylinder? Not sure, but they are cheaper I believe
Is it worth getting the tick master cylinder for 300 bux or should I just stick with a new stock master cylinder? Not sure, but they are cheaper I believe
#25
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My own belief is that the installed base of Tick masters is too small and not enough user-miles have accumulated to establish a reliability factor for the product.
Like any clutch-related product, rave reviews immediately after installation are not very credible. Rather, we need the test of time in actual use.
I've done that testing myself through three Z06s and am very satisfied with the stock master cylinder with proper maintenance of the clutch fluid.
Ranger
#26
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How quickly does the fluid get dirty with normal and occasional spirited driving? I mean is this something I'll have to do every 1/4 event, or every gas fill up?
#27
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The color reflects the amount of clutch dust in the fluid. You want to keep that to a minimum. It's clutch dust that progressively destroys the master cylinder seals.
At the drag strip I start the day with pristine fluid and after 3-6 passes, I swap the fluid in the reservoir once or twice. Then swap again a couple days later. Goal is to keep the content of the reservoir clear of the suspended black bits that are clutch dust.
Swapping the reservoir fluid takes just 2-3 minutes once you learn the process.
How often you need to swap the fluid depends entirely on driving style. Clutch dust uptake is higher during launches and high-rpm up-****s and down-shifts.
Ranger
Last edited by Ranger; 12-19-2010 at 09:47 AM.
#28
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I just looked up a gm master cylinder at all online gm part stores. None of them have it... Link to one?
How much do they usually go for?
Ok, found a few at rock auto.. Which one would be best out of those?
http://www.rockauto.com/catalog/x,ca...,parttype,1996
Still going to try the fluid flush, but this is just incase
How much do they usually go for?
Ok, found a few at rock auto.. Which one would be best out of those?
http://www.rockauto.com/catalog/x,ca...,parttype,1996
Still going to try the fluid flush, but this is just incase
Last edited by Z06seal; 12-19-2010 at 10:03 AM.
#30
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http://forums.corvetteforum.com/c6-z...-and-cure.html
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#31
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I did watch the video. Very informative. I was just making sure that was all that the job entailed. I was also wondering why two fluids are shown? Just to show two options of which brand of fluid to use?
I thought it would be something to where you had to bleed the entire system somehow.
I thought it would be something to where you had to bleed the entire system somehow.
#32
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I did watch the video. Very informative. I was just making sure that was all that the job entailed. I was also wondering why two fluids are shown? Just to show two options of which brand of fluid to use?
I thought it would be something to where you had to bleed the entire system somehow.
I thought it would be something to where you had to bleed the entire system somehow.
As for which fluid, the sticky thread contains a link to a list of high quality DOT4 brake fluids, any one of which will work well in the clutch. The fluids shown in the video are the ones I personally use. But any fluid on the linked-list should be fine.
Ranger
#33
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When I take my car out for a spirited drive, the pedal gets mushy, and at about 20% pushed in, it's very loose, almost like air is in the line. it sometimes won't even come back up once it gets to that 80% out point and I have to pull it with my foot.
This usually happens let's say I go 0-100ish or just do a lot of high rev shifting.
I believe this is a known problem, and the only related search I got was a thread from 2002 so I didn't wanna bump that up.... Some people have said it's the master cylinder/slave and I need to get one that's made by TIC or something?
Thanks!
This usually happens let's say I go 0-100ish or just do a lot of high rev shifting.
I believe this is a known problem, and the only related search I got was a thread from 2002 so I didn't wanna bump that up.... Some people have said it's the master cylinder/slave and I need to get one that's made by TIC or something?
Thanks!
For a good read, check out our FAQ here: http://www.tick-performance.com/tick...aulics/#master
#34
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I spend about one hour per year maintaining my clutch fluid at a cost of about $20 inclusive. My clutch hydraulics are stock GM, which behaved normally through 500 passes at the drag strip in C5 Z06s and produced 11.81 bone stock on stock tires and 11.52 on drag radials with a cold-air intake.
Owners ought to be highly skeptical of vendor claims that aftermarket hydraulics will produce "ton faster shift speeds." In fact the speed of a shift is governed by how fast the driver's leg speed is in cycling the clutch pedal from all-out to all-in to all-out. A very fast time is a duration of 250 milliseconds, which is attained by many fast drivers with stock hydraulics.
Ranger
Owners ought to be highly skeptical of vendor claims that aftermarket hydraulics will produce "ton faster shift speeds." In fact the speed of a shift is governed by how fast the driver's leg speed is in cycling the clutch pedal from all-out to all-in to all-out. A very fast time is a duration of 250 milliseconds, which is attained by many fast drivers with stock hydraulics.
Ranger
Last edited by Ranger; 12-20-2010 at 08:55 PM.
#35
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I spend about one hour per year maintaining my clutch fluid at a cost of about $20 inclusive. My clutch hydraulics are stock GM, which are behaved normally through 500 passes at the drag strip in C5 Z06s and produced 11.81 bone stock on stock tires and 11.52 on drag radials with a cold-air intake.
Owners want to be highly skeptical of vendor claims that aftermarket hydraulics will produce "ton faster shift speeds." In fact the speed of a shift is governed by how fast the driver's leg speed is in cycling the clutch pedal from all-out to all-in to all-out. A very fast time is a duration of 250 milliseconds, which is attained by many fast drivers with stock hydraulics.
Ranger
Owners want to be highly skeptical of vendor claims that aftermarket hydraulics will produce "ton faster shift speeds." In fact the speed of a shift is governed by how fast the driver's leg speed is in cycling the clutch pedal from all-out to all-in to all-out. A very fast time is a duration of 250 milliseconds, which is attained by many fast drivers with stock hydraulics.
Ranger
#36
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The Ranger method plus a Tick remote bleeder w/ Monster clutch works for me:
http://forums.corvetteforum.com/c5-z...p-the-zo6.html
http://forums.corvetteforum.com/c5-z...p-the-zo6.html
#37
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I posted this same thing at another forum, and I was told this can also be caused from my longtubes which get really hot near the master cylinder, which can cause the master cylinder fluid to boil....
so I was told to get some hi temp brake fluid that's used for racing
I found these:
Wilwood EXP 600+ (highest dry/wet boiling points) which cost almost 20 bucks per 12oz. my local speed shop has this. It also says in description not to dilute this with other brake fluids and that it should be used on a new brake system. which I can't do. I'll have to use the ranger method
Next is Motul RBF 600. It's about the same temps as the Wilwood EXP but bit less on cost. it's 15 bux per 17oz
and lastly is the Wilwood Hi Temp 570 Brake fluid. Lowest numbers (570 dry, not sure wet) but it's also the cheapest at 7 bux per 12oz.
Any reccomendations on which to get to see if higher temp fluids might help with my problem? I'll have to pump and flush the fluid at least 5 times to get it going, so that can get real expensive with the higher priced ones. and I'll do it again next week to try to flush all the old fluid out...
and will these high temp racing brake fluids cause any issues on a DD Z06?
lastly, what is a dry and what is a wet boiling point? differences?
Thanks!
It might be worth a shot before I spend money on a tick master at 300 bux plus install if these high temp fluids will do the job...
so I was told to get some hi temp brake fluid that's used for racing
I found these:
Wilwood EXP 600+ (highest dry/wet boiling points) which cost almost 20 bucks per 12oz. my local speed shop has this. It also says in description not to dilute this with other brake fluids and that it should be used on a new brake system. which I can't do. I'll have to use the ranger method
Next is Motul RBF 600. It's about the same temps as the Wilwood EXP but bit less on cost. it's 15 bux per 17oz
and lastly is the Wilwood Hi Temp 570 Brake fluid. Lowest numbers (570 dry, not sure wet) but it's also the cheapest at 7 bux per 12oz.
Any reccomendations on which to get to see if higher temp fluids might help with my problem? I'll have to pump and flush the fluid at least 5 times to get it going, so that can get real expensive with the higher priced ones. and I'll do it again next week to try to flush all the old fluid out...
and will these high temp racing brake fluids cause any issues on a DD Z06?
lastly, what is a dry and what is a wet boiling point? differences?
Thanks!
It might be worth a shot before I spend money on a tick master at 300 bux plus install if these high temp fluids will do the job...
#38
Race Director
In a perfect mechanical environment, the speed of a shift is indeed governed by how fast the driver's leg speed is in cycling the clutch pedal from all-out to all-in to all-out. It's great that your stock master cylinder is working for your setup. Unfortunately, many Corvette owners (myself included) haven't been so lucky, especially when using aftermarket clutches. Installing our kit on a car with 0 mechanical issues will make a slight improvement (if for no other reason than the shorter pedal), but installing our kit on a car with even minimal clutch disengagement issues will result in a HUGE improvement, making it much easier to shift a ton quicker.
What, specifically, do you mean by "shorter pedal"? BTW, I've got one of your masters, and haven't adjusted it from it's stock setting. It seems to engage (narrower) higher off the floor than the stock unit, and the pedal effort is higher, but I've also got a new twin-disc clutch, so that could also be a by-product. If I use the turnbuckle adjustment, will I be able to get the engagement point closer to the floor?
#39
Tech Contributor
Ranger:
I have been doing your method for years now thanks !
One question I have though.
By cleaning the reservoir, and replacing the fluid then pumping the clutch.... does that push ALL the NEW fluid into the clutch ? Should I be able to do it this way with an entire bottle of fluid and it all get in there ?
I normally do the empty/clean/refill then drive a while, then empty/clean/refill after my next drive.
I was wondering if my method is adding moisture to the fluid opening it so often.
Thanks !
Toque
I have been doing your method for years now thanks !
One question I have though.
By cleaning the reservoir, and replacing the fluid then pumping the clutch.... does that push ALL the NEW fluid into the clutch ? Should I be able to do it this way with an entire bottle of fluid and it all get in there ?
I normally do the empty/clean/refill then drive a while, then empty/clean/refill after my next drive.
I was wondering if my method is adding moisture to the fluid opening it so often.
Thanks !
Toque
#40
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Ranger:
I have been doing your method for years now thanks !
One question I have though.
By cleaning the reservoir, and replacing the fluid then pumping the clutch.... does that push ALL the NEW fluid into the clutch ? Should I be able to do it this way with an entire bottle of fluid and it all get in there ?
I normally do the empty/clean/refill then drive a while, then empty/clean/refill after my next drive.
I was wondering if my method is adding moisture to the fluid opening it so often.
Thanks !
Toque
I have been doing your method for years now thanks !
One question I have though.
By cleaning the reservoir, and replacing the fluid then pumping the clutch.... does that push ALL the NEW fluid into the clutch ? Should I be able to do it this way with an entire bottle of fluid and it all get in there ?
I normally do the empty/clean/refill then drive a while, then empty/clean/refill after my next drive.
I was wondering if my method is adding moisture to the fluid opening it so often.
Thanks !
Toque
Assertions that removing the cap on the reservoir will rapidly corrupt the fluid with water are overdrawn. The reservoir contains about 33% of the entire fluid capacity of the system. Keeping the cap off for 60-120 seconds to swap in 33% new fluid will reduce water content, not increase it. And that is true for each successive swap.
I’ve done a series of experiments where, with an open hood, I left the cap off the reservoir for 36-hours on a hot, extremely humid day in an unconditioned garage. I then capped the reservoir and made repeated runs through the gears with 7K 1-2, 2-3 and 3-4 shifts. The hydraulics performed flawlessly. Moreover, the DOT4 brake fluid I use is kept capped when not in use; but a 12-ounce can is used up over a 30-60 day period of fluid swapping. That routine has never presented an issue of water corruption of the clutch fluid in my car through 773 drag strip passes.
So the process you are using seems consistent with excellent practices.
Ranger