Clutch Master Cylinder Question
Thread Starter
Drifting
Joined: Jun 2009
Posts: 1,287
Likes: 448
From: Upstate NY
Clutch Master Cylinder Question
My current wack-a-mole 
... the clutch master cylinder.
In the spring I replaced the master & slave and flushed the lines, bled it and it worked great all summer.
I just recently replaced the clutch, PP, T/O bearing, pilot & flywheel and everything worked great for a couple of days.
I started getting a low peddle, so I bled the system and it worked good for about a day and then started getting low again -no change in the fluid level in the resevoir at any time.
One thing that I did notice is that the fluid was very cloudy -even though everything was replaced in April.
This morning the level was fine, but there is absolutely NO peddle, even when I pump it very fast.
So the master must be defective?
Has anyone had a similar problem with the inexpensive replacements -this one is from Advanced Auto, but Auto Zone & others look the same and are all $35.00 - $38.00.
Is there a better one that I should get or just get the warrenty replacement?
... the clutch master cylinder.In the spring I replaced the master & slave and flushed the lines, bled it and it worked great all summer.
I just recently replaced the clutch, PP, T/O bearing, pilot & flywheel and everything worked great for a couple of days.
I started getting a low peddle, so I bled the system and it worked good for about a day and then started getting low again -no change in the fluid level in the resevoir at any time.
One thing that I did notice is that the fluid was very cloudy -even though everything was replaced in April.
This morning the level was fine, but there is absolutely NO peddle, even when I pump it very fast.
So the master must be defective?
Has anyone had a similar problem with the inexpensive replacements -this one is from Advanced Auto, but Auto Zone & others look the same and are all $35.00 - $38.00.
Is there a better one that I should get or just get the warrenty replacement?
Platinum Supporting Vendor
Joined: Sep 2010
Posts: 533
Likes: 2
C4 Corvette Clutch Hydraulics
Take a look,
If you have any questions feel free to give me a call.
Tom 1-800-962-9632 ext 240.
Take a look,
If you have any questions feel free to give me a call.
Tom 1-800-962-9632 ext 240.
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Thread Starter
Drifting
Joined: Jun 2009
Posts: 1,287
Likes: 448
From: Upstate NY
C4 Corvette Clutch Hydraulics
Take a look,
If you have any questions feel free to give me a call.
Tom 1-800-962-9632 ext 240.
Take a look,
If you have any questions feel free to give me a call.
Tom 1-800-962-9632 ext 240.
Platinum Supporting Vendor
Joined: Sep 2001
Posts: 3,665
Likes: 341
They do look the same but they are not. We purchase our from straight from the manufacture and the wholesale from the manufacture if more expensive then the retail of the Advance auto/auto zone part. I don't know anything about what they are selling, but you are comparing apples to oranges.
Customer has a 84, the steel tube did not come out until 89.
We saw the exact opposite. The steel was the original and I don't ever remember those failing when the cars were new. When the slave came from GM they were not failing. After they were disc.and napa had a steel one they were ok, not many failures but some. When EVERYONE changed to the cast iron, they all failed I would say 98% of the ones we sold had issue. Now the OEM was reproduced and I have had no returns that I am aware of since.
I have had poor luck with multiple examples of the mandrel-drawn cyls, oem or oem replacement. They have had a high failure rate. The cast cyls seem to be better. Check w/ Bill Boudreau at zfdoc.
We saw the exact opposite. The steel was the original and I don't ever remember those failing when the cars were new. When the slave came from GM they were not failing. After they were disc.and napa had a steel one they were ok, not many failures but some. When EVERYONE changed to the cast iron, they all failed I would say 98% of the ones we sold had issue. Now the OEM was reproduced and I have had no returns that I am aware of since.
Thread Starter
Drifting
Joined: Jun 2009
Posts: 1,287
Likes: 448
From: Upstate NY
I agree that there must be something different in these for them to cost so little -at this point it is being replaced under warranty, so I guess I'll try another and if it fails, I'll get a more expensive one assuming that it will be a better quality.
Thanks
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2nd Gear
Joined: Jan 2011
Posts: 2
Likes: 0
I have an 86 with less than 50,000 miles on it. It has been maintained to the hilt and is in like new condition. The original clutch master cylinder failed three years ago. In the last three years I have gone through four master/slave cylinders. All were Delco parts put on by the Chevy dealer. Now they tell me that they can no longer repair the car. They say that as of about five years ago they sold the rights to make the cylinders to a company in China and since they have had so many failures, they have ended that arrangement. They also have no plans to make any more. So if my dealer is correct, anyone with a 1984-88 Corvette will no longer be able to get a factory master or slave cylinder.
Right now my Vette is sitting in the garage undrivable because I don't want to spend a bunch of money on another clutch master cylinder that is just going to fail, and I don't know what brand to buy that is not a Chinese knockoff. After all, I trusted Delco.
Have been considering sleaving the current cylinders. Any advise will be appreciated. I would love to find a clutch master cylinder that doesn't fail in a few months. Can't even drive the car very far for fear it will end up beside the road.
Right now my Vette is sitting in the garage undrivable because I don't want to spend a bunch of money on another clutch master cylinder that is just going to fail, and I don't know what brand to buy that is not a Chinese knockoff. After all, I trusted Delco.
Have been considering sleaving the current cylinders. Any advise will be appreciated. I would love to find a clutch master cylinder that doesn't fail in a few months. Can't even drive the car very far for fear it will end up beside the road.
Melting Slicks
Joined: Jan 2009
Posts: 3,482
Likes: 196
From: folsom california
may I suggest using DOT 5, silicon based brake fluid in your clutch systems ? Silicon based fluid preserves, rather than degrades the seals in your system. Conventional fluid tends to turn black....the black part used to be part of a seal. Conventional fluid will literally remove paint. silicon will not. Plus silicon based fluid is more viscous than conventional fluid. While this increased viscosity makes it unsuitable for use in ABS brake systems, in non ABS systems, or clutch hydraulics, everything else being equal, the increased viscosity will tend to seal better against minor imperfections in the cylinder bore.
Drifting
Joined: Jun 2010
Posts: 1,853
Likes: 8
From: Westerly RI
I have an 86 with less than 50,000 miles on it. It has been maintained to the hilt and is in like new condition. The original clutch master cylinder failed three years ago. In the last three years I have gone through four master/slave cylinders. All were Delco parts put on by the Chevy dealer. Now they tell me that they can no longer repair the car. They say that as of about five years ago they sold the rights to make the cylinders to a company in China and since they have had so many failures, they have ended that arrangement. They also have no plans to make any more. So if my dealer is correct, anyone with a 1984-88 Corvette will no longer be able to get a factory master or slave cylinder.
Right now my Vette is sitting in the garage undrivable because I don't want to spend a bunch of money on another clutch master cylinder that is just going to fail, and I don't know what brand to buy that is not a Chinese knockoff. After all, I trusted Delco.
Have been considering sleaving the current cylinders. Any advise will be appreciated. I would love to find a clutch master cylinder that doesn't fail in a few months. Can't even drive the car very far for fear it will end up beside the road.
Right now my Vette is sitting in the garage undrivable because I don't want to spend a bunch of money on another clutch master cylinder that is just going to fail, and I don't know what brand to buy that is not a Chinese knockoff. After all, I trusted Delco.
Have been considering sleaving the current cylinders. Any advise will be appreciated. I would love to find a clutch master cylinder that doesn't fail in a few months. Can't even drive the car very far for fear it will end up beside the road.
Instructor
Joined: Oct 2006
Posts: 246
Likes: 2
From: Elk Plain WA
St. Jude Donor '11
Slightly Off Topic - But Very Much Related
How did you guys get to the inboard bolt that holds the clutch master cylinder to the firewall?
I don'tsee a way to slide a socket in there, even with an extension on my 86!
How did you guys get to the inboard bolt that holds the clutch master cylinder to the firewall?
I don'tsee a way to slide a socket in there, even with an extension on my 86!
Drifting
Joined: Jun 2010
Posts: 1,853
Likes: 8
From: Westerly RI
Did you remove the battery? That gives you the access to the clutch cyl.
Thread Starter
Drifting
Joined: Jun 2009
Posts: 1,287
Likes: 448
From: Upstate NY
