Can the master cylinder be replaced in the car?

[Chris Lovell]

I read Bob's tech article on Master Cylinder replacement. He suggests taking the vac boost, master cylinder, pedal cluster, etc out completely. If I am interested in only replacing the Master Cylinder, can I do this in the car? Is this just a bad idea? I did exactly this repair on a big roomy truck recently and it was easily done as a "hot swap". I was hoping for the same situation with the 911.
Thanks for any advise as usual.

[Formerly Steve Wilkinson]

Who's Bob?

As for your question, yes, the master cylinder can be replaced in the car.

[ikarcuaso]

Must be Bob Tindel

http://www.pelicanparts.com/techarticles/911_master_cylinder/911_master_cylinder.htm

[ianc]

Yes, it can, and rather handily,

ianc

[Chris Lovell]

"Who's Bob?" Funny. Yes, Bob Tindel's Tech Article. Sorry about that.
Thanks for the responses. I will plan to work only from the trunk leaving the painful driver's floor work to another day, if at all.
If anyone has any tips on master cylinder replacement (such as removal of the hood itself), I am listening. Also, would blowing out the brake fluid from the lines and calipers, as Bob Tindel suggests, be a good idea as part of this project? I am definitely replacing pads and bleeding (duh!) all around.
Thanks.

[tonythetarga]

I think blowing out the lines is a bit overkill for a master cylinder replacement. Make sure you use a new O ring for the m/c and that it is in place before you button it up. You might consider removing the reservoir and cleaning it while it is off to keep your system as clean as possible. Use good brake fluid. Removing the hood id not necessary either. Just pull off the cardboard cover around the fresh air blower and go to it.

[Chris Lovell]

Thanks Tony and all.

[euro911sc]

I did that replacement. Easy. Just make sure you use a turkey baster to remove as much fluid from the resv. as possible and surround your working area in the trunk with tons of newspaper to soak up any drips. You still may end up on the floor adjusting the brake bar from pedal to booster assy as needed.

Enjoy!

-Michael

[KTL]

I've done it both ways (in the car and out of the car with the booster & bulkhead removed) and I recommend doing it out of the car to save yourself some cursing.

IMO it's not that much more work to remove the booster & bulkhead assembly, and it gives you an opportunity to clean the area when everything's out of the way. I actually ended up having to paint my trunk a bit because of previously spilled brake fluid and peeling paint. Plus I found the ventilation hoses and cables to be an annoying obstruction when trying to do the work within the tight confines of the booster area, booster installed in car.

To each his own. Good luck and take your time.

[JeremyD]

I'll agree with Kevin - you can do either way - but so much easier taking the whole assembly out. (and the opportunity to clean) I would also recommend you replace the brake light switches with it removed. They have a limited life - and that is mucho easier to do with the MC out.

You don't need to remove the pedal cluster though - just remove the brake linkage. Be careful when you remove the brake fluid reservoir - it tends to get brittle over the years and makes it much easier to brake off one of the overflow tubes.