Brake master cylinder advice needed

[Forssling]

Hi All,
I'm currently restoring a 71 911T. I will run stock setup on brakes and calipers.

My questions are, should I:
1) Restore my original master cylinder?
2) Get a new one?
3) Upgrade? (I understand SC:s had bigger bore. Would that make sense on my otherwise original setup?)

Thanks for any input!

Jörgen Forssling
Göteborg
SWEDEN

[Bill Verburg]

Originally Posted by Forssling

Hi All,
I'm currently restoring a 71 911T. I will run stock setup on brakes and calipers.

My questions are, should I:
1) Restore my original master cylinder?
2) Get a new one?
3) Upgrade? (I understand SC:s had bigger bore. Would that make sense on my otherwise original setup?)

Thanks for any input!

Jörgen Forssling
Göteborg
SWEDEN

back is those days there were several m/c available for 911.
These days not so much

In the Us a tandem 19.05m m/c was used which had a provision for a brake failure warning. I'm not sure that the RoW versions had that.

Any hoe as far as I can determine only that m/c is still available thru Porsche
911.355.012.02, If your car isn't set up for the brake warning you can just not use it.

There are/were 2 alternate larger m/c that can be used

1 is a 20.5 that was only used oe in 1969
901.355.012.04 Porsche
3.2120-3901.3 ATE
This is a very nice upgrade for the performance oriented 911/914 driver. There is a small increase in pedal effort but the higher harder pedal is worth it to most.
Note that I haven't seen one in 40 or so years so don't know if it's still available.

The other is a 23.8mm that is most commonly used w/ 930 brake upgrades on non boosted cars. It's best to buy in kit form which includes grommets, feedlines, feed fittings and the mandatory longer actuating rod

there are 2 different versions ports left and ports right
the version you want for a left hand drive car is ports left
03-2123-3402.3

Some track guys use these w/ stock brakes because it allows finer control of the brakes w/ a very much higher and harder pedal but most will no want to live w/ the very high pedal effort when used w/ stock brakes. This one will be a bear even w/ 964 brakes.

You can not use the later 20.6mm or 23.8mm m/c for boosted brakes unless you convert the whole system to boosted. This is a non trivial job.

[manbridge 74]

Bill, do you know if anyone has ever taken their 19mm M/C to a machine shop to bore it to one of the larger sizes? This would allow a guy to use a rebuild kit and maybe the SC piston to achieve the harder pedal.

[jrsully]

just find a new 19mm ATE replacement if your restoring a stock 71 system. The system will work fine and be reliable. Don't get a replacement, get an orig ATE

[mb911]

914rubber is making a really nice 19mm m/c it is designed for the 914,912, 911s.

[SalParadise]

Originally Posted by jrsully

just find a new 19mm ATE replacement if your restoring a stock 71 system. The system will work fine and be reliable. Don't get a replacement, get an orig ATE

I second this. Find an ATE at all and any costs. Stay away, very far away, from any URO master cylinder. One damn near killed me and my car. Do not be tempted by their availability and cheaper prices.

[mb911]

Originally Posted by SalParadise

I second this. Find an ATE at all and any costs. Stay away, very far away, from any URO master cylinder. One damn near killed me and my car. Do not be tempted by their availability and cheaper prices.

Agreed thats why 914rubber made their own.. It looks almost identical to stock..

[Forssling]

I'll will buy an ATE. My vendor in Germany has ATE for my model but in two different versions. With or without warning light contact.

I'm not sure what I have on my original, but I have a switch on my pedal assembly so I guess I need the one without?

What stated the two different versions for a 71 car? T, E or S? Destination country? Something else?

Thanks for all your help!

Jörgen

[Jack Stands]

I’ve heard that even the new Ate master cylinders can have issues. I’d go with the version that Mikey914 has reproduced as an alternative that’s made in the USA.

[chrismorse]

The MC is the heart of the most important system in the car. Your life literally depends on it.
The Snap-On motto comes to mind,"long after the sweetness of a low price is forgotten, the bitterness of low quality remains".

Or, as a placard on my favorite civil engineer's office wall proclaims, "If you want first quality oats, you are going to have to pay the price. BUT, if you are willing to settle for oats that have passed through the horse, the price MAY be less".

Chris