swftiii

All,

My brake issues have continued and gotten a little worse. I gathered brake rotor temperatures last weekend at the club race and found I am running between 560 and 610 C. These temps aren't crazy and shouldn't be causing the soft pedal issue becuase I use SRF and Pagid Yellow/Blacks.

So, my next step is to replace the brake master cylinder. It has now failed the constant pressure test, so I purchased a replacement and was looking for some DIY instructions. I could swear I've seen them here before, but can't seem to find them again, so can someone either point me to some instructions or provide some DIY steps to help me with this project.

Thanks,

-Skip

swftiii

All,

I've done some research and have the replacement master cylinder ready to go. In looking at the master cylinder, there are 4 brake lines that need to attach to the master cyliner. Two of them are threaded and self explanatory, but there are two others that I cannot figure out how they attach (see picture below). How do the lines attach to the 2 openings in the picture below? Are there fittings that just slide in and the friction keeps them there? If so, then I assume there is no pressure on the lines.



My plan is to drain the brake reservoir and then work to remove and replace the master cylinder. If anyone has additional thoughts or guidance, please let me know.

Thanks,

-Skip

jimq

thats one funky looking master cylinder!

swftiii

Jim - am I missing something? It looks just like the one on my car and other pictures I've seen. I'll have to remove the one on the car from the booster and the brake lines and then hook this one up in its place.

Let me kmow if I'm missing something.

-Skip

Makmov

I know, strange, but that's the what the 964 master looks like.

Not quite sure how those lines are put in but they are just the reservoir feed. So there is no pressure there.

ChaseN

They're just a slip-fit IIRC. The lines from the remote reservoir are "barbed" slightly. They just push straight on.

One of the benefits of this system is that you can change a 964's master without draining all the brake fluid, if you wish - pull the remote reservoir lines out of the master, and plug them quickly with your finger, then use a piece of duct tape or similar to cover them quickly.

Even if you want to completely flush the fluid, this keeps you from having to use as much new fluid. Use the old fluid in the reservoir to bleed the brakes, then crack each bleeder until new fluid comes out. This works especially well with differing color fluid (like ATE Super Blue/Typ 200).

swftiii

Guys,

OK A LITTLE HELP NEEDED PLLLEEAASSSSEEEE

I've got the master cylinder unhooked everywhere except the 'barbed plastic fitting' that Chris shared. Since it it on the top of the MC and hard to see I'm struggling to get the fittings to back out. It looks like the fittings have a small disk on the top that is part of the hose and plastic fitting, so I tried gently sliding a small screw driver under the edges to loosen it up, but just cannot get them to back out of the rubber fittings. I'm nervous to break the fitting, so any idea or recommendation?

Thanks everyone,

-Skip

Indycam

If you are talking about the "red arrows" above
pull like a sob , they will give .

swftiii

The saga continues...

Installed replacement master cylinder, bled system numerous times and have a soft pedal. Next step is to cycle the ABS and bleed to get the air out of the ABS (per Steve Weiner's recommendation). Borrowed a Porsche Hammer from a local Porsche nut and hooked it up to find that the Hammer doesn't find, read, or offer an option to get to the ABS system. The Hammer only provides/reads airbag, dme, and heating system options on the main menu where the ABS should be.

Any ideas? I am frustrated and just want to get the car back on the street and enjoy driving it again...

Thanks for any suggestions,

-Skip

Indycam

Find some place where you can lock up the tires with ease . Dirt road , grass , oiled up parking lot ...
Lock up the tires , that will cycle the abs .

ChaseN

Try a spirited drive on some of those rural (traffic-free) roads around you. I wouldn't be surprised if your pedal firmed up after a good amount of *fairly* heavy braking. For some reason I always have to do this anytime after I do any brake work on my 964 (but none of my other cars require this).

How are you bleeding it? Pressure, vacuum, or 2-man method?

BTW, the name's Chase

swftiii

Thanks Guys - I'm going to clean the ABS contacts and see if that does anything to get the Hammer to see the ABS system. If not, I'll put her back together and go for a drive and see what happens with that.

Chase - I have been using the Motive Pressure bleeder like everyone recommends and it has worked for me for years.

Thanks Guys - I'll keep you all posted.

Skip

swftiii

OK, got the system correctly bled and the brakes work fine, but the pedal still feels a little soft and the brakes don't engage until pretty low in the movement of the pedal.

In talking to a 993 buddy of mine he mentioned he chased something like this on his car for a while and ended up fixing it by the shop “adjusting the brake pedal throw on the master cylinder”. Is there something like this on the 964s?

Thanks,

-Skip