I have had 3 GT2 master cylinders fail in 1500 miles since installing a EVOMS GT2 conversion. The shop I use a seen several other units fail in short order in the last year. I am wondering if there is a bad batch out there ? and also if there might be another choice for parts that would be better than the failing OEM solution.

 

Are you using brake fluid? Flush all the chs11 out? the seals are different for both systems and do not interchange.

 

The shop said they did I will check again, thanks

 

I did a gt2 slave install about a year and a half ago. After only 500 miles or so the master got real squeaky and notchy. The notchiness made it hard to accurately engage the clutch. Based on what I read and after I talked with a few mechanic buddies it sounded like the master was on its way out, so I just went ahead and replaced it. It's been perfect ever since.

And before anyone asks, yes I used brake fluid and yes I flushed the heck out of the system so it definitely wasn't the pentosin that kill the master.

 

This is my experience as well sure seems like there may be a problem with this part

 

Or maybe it is an issue with the Kit design causing more load on the part than it was designed for?

 

I doubt it. There shouldn't be any more pressure on the parts than a gt2 puts on them. The only part that may see different loading because of its mounting is the slave. I think it was probably just some bad qc on the seals. Either it was a bad batch or we were just the lucky ones that got the 1% of bad masters and the Internet has connected us haha.

 

I've never had an issue with mine. Been years of heavy daily driving, but I did mine myself as well as built my own kit.

 

One thing to think about...do not bleed clutch traditionally (pressurizing it by foot), it'll break the master cylinder. Use only power bleeder and WSM's instructions.
Master cylider's construction is quite weak (plastic shaft and thin metal tube around it, as piston).
Squeaking and notchyness sounds like that the tube acting as the piston has been expanded sightly because the pedal's been pressed by a foot when beleeding it. When the piston is not properly seated (= in it's normal movement area) in the cylinder excessive force will expand it breaking the assy.
I had to change one before realizing how it must be done...my wife was pressing the pedal and had enough force to break it...

 

I only used a pressure bleeder when I bled my clutch. So it's not that.

 

Ditto. I would like to lighten the pedal a bit though. It is hard to depress after driving a while.

 

Make sure you have the stiffer GT2 assist spring installed.

 

Got a part #? There are a few listed on the microfiche.