23 mm Brake Master cylinder install question?

[mnmasotto]

I bought a 23mm turbo brake master cylinder for my 1987 Carrera. My original MC has the two (2) prong MC Brake Lamp Switchs but the new turbo 23mm MC has the three (3) MC Brake Lamp Switches. Can I simply install my original two (2) prong swithces on my new 23mm MC?

Also, I have 993TT front brakes and 993 rear brakes installed. Do I need a new brake proportion valve? If so, which one?

Thanks Mark

[don911]

You can put your old swithes in the 23 mm MC. I did this when I installed 930 brakes.

Can't help on the prop. valve question.

[spuggy]

Originally Posted by mnmasotto

Also, I have 993TT front brakes and 993 rear brakes installed. Do I need a new brake proportion valve? If so, which one?

IF you meant to say that you're going to 993TT front and rear, then you need to remove the proportioning valve, IMO.

If you really meant what you typed above, then you'll need to do the math to work out what the F/R ratio is, and whether that is acceptable for your intended setup, usage and personal preferences.

Note that the 3.2 is the only 911 to have a proportioning valve (to limit lockup due to the huge single-piston rear caliper).

If you're really using 993TT fronts with 993 rears, I think there might be a danger that the fronts will lock-up way too soon, not that you need to limit the pressure to the rear. But do the math.

[Bill Verburg]

Originally Posted by mnmasotto

I bought a 23mm turbo brake master cylinder for my 1987 Carrera. My original MC has the two (2) prong MC Brake Lamp Switchs but the new turbo 23mm MC has the three (3) MC Brake Lamp Switches. Can I simply install my original two (2) prong swithces on my new 23mm MC?

Also, I have 993TT front brakes and 993 rear brakes installed. Do I need a new brake proportion valve? If so, which one?

Thanks Mark

It helps to know what rotors are being used, I assume 322x32 front, maybe 309x28 rear?

Anyway no p/v will be needed.

[mnmasotto]

Bill, You are correct. I did not know that was a factor. How do I take out the existing P.V.? What do I put in its place?
Thanks In Advance, Mark

[KTL]

Mark,

You put nothing in it's place. Some people just straighten the factory line and use the union to join the two ends of brake lines. Or you can bend a new piece of line from the master cylinder to the union.

[Bill Verburg]

Originally Posted by mnmasotto

Bill, You are correct. I did not know that was a factor. How do I take out the existing P.V.? What do I put in its place?
Thanks In Advance, Mark

Replace the line or extend it.

[CBRacerX]

Originally Posted by KTL

Mark,

You put nothing in it's place. Some people just straighten the factory line and use the union to join the two ends of brake lines. Or you can bend a new piece of line from the master cylinder to the union.

I did the same upgrade to my 87 - and was able to just connect the lines without adding any new pipe.

Enjoy!

[mnmasotto]

O.K.
I have established that I need to remove the Brake Pressure Regulator. I called VCI this morning. They said Porsche makes a bypass line which omits this valve but they did not know the part number. I called a few people but they can't find any evidence of such a part. Does anyone have the part number or any other possible solutions. I am not sure my car has enough excess brake line to simply pull the two existing lines together.

Everyones help is much appreciated!!

[Bill Verburg]

There used to be one but lst I checked it was nla, if you don't want to stretch what you have
1) replac e w/ an SC line, same thing just doesn't have the p/v provision
2) get a short piece of 3/16" brake line and 2 fittings

[KTL]

If you don't want to wait for a Porsche part to arrive special order, go to the local auto parts store and get a 12" straight length of 3/16 metric line with fittings that is already pre-flared (bubble flare). I buy these all the time at Murray's or Advance Auto.

All you need to bend it is your hands and a large socket. Parts store might even have a cheapo bending tool for a few bucks that might come in handy.