Master cylinders M20F

[FastTex]

I just went through the annual pretty much ok but it looks like the left master cylinder, even with the new seal kit, has some issues (sometime I have to push the pedal very low) confirmed by my A&P.

A quick inquiry with LASAR prices these things around $700 (!!!).

What's the preferred path? Rebuilding them or new? Is there some other place where to buy at a more reasonable price?

Thanks!

[Andy95W]

I'd replace the o-ring in the left caliper and the left brake pads as well.  While you're at it, check the thickness of the left brake disc to make sure it's  within specs. 

I think your real problem is simply air in the left side of the system.  The above recommendations are fairly inexpensive but will require re-bleeding the left brakes which ought to fix the problem.

After that, I'd re-replace the o-rings in the left master cylinder. It's fairly easy to roll an o-ring in those, particularly around the shaft, which could now be sucking air.

[FastTex]

12 hours ago, Andy95W said:

I'd replace the o-ring in the left caliper and the left brake pads as well.  While you're at it, check the thickness of the left brake disc to make sure it's  within specs. 

I think your real problem is simply air in the left side of the system.  The above recommendations are fairly inexpensive but will require re-bleeding the left brakes which ought to fix the problem.

After that, I'd re-replace the o-rings in the left master cylinder. It's fairly easy to roll an o-ring in those, particularly around the shaft, which could now be sucking air.

Seal kit and O-rings have already been replaced. My A&P says it was very difficult to bleed it and air might be back...not sure if master cylinders can be overhauled or it's better buy new ones? Is LASAR the only place? 

[Andy95W]

Master cylinders can be overhauled unless either the shaft or cylinder has been damaged or is pitted. Standard o-rings. 

It sounds like you still have air in the left brake.  They can be a real bear to get bled completely.