SI 330 Brake Master Cylinder

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tyang
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SI 330 Brake Master Cylinder

Post by tyang »

Hi All,

I've been pulling my hair out on a SI 330 brake system and I need the help of other SI 330 owners. What I basically need is someone with a SI 330 that has his Master Cylinder out of their car so they can measure the bore of the Master cylinder. They're usually in inch measurements 3/4, 7/8, 1-inch, etc. It's important to note that I need a M/C from a SI 330 with a dual circuit master cylinder designed to work with a dual booster set up. Ferrari only used this set up for less than 400 cars before installing hung pedals with a mastervac system.

I've rebuilt the brake system on this SI 330 and at the final stage of bleeding, the pedal moves a lot more than it should. I can get boost, but there is just too much pedal travel. This car came into the shop with a failed master cylinder, so it's hard to know exactly what the brakes felt like before I rebuilt the whole system. I've tested the boosters and they're working correctly with the right amounts of input and output pressures on the gauges. We suspect the M/C was changed on this car with a similar external dimensions but a different internal bore. With an incorrectly matched M/C, it may be the cause of my problems.

Thanks to anyone who can help!

Tom
'63 330 America #5053
Pied-Noir
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Re: SI 330 Brake Master Cylinder

Post by Pied-Noir »

Tom,

On my S1- 6087 delivered in 06/64, it's 1 inch all the way through. It's difficult to get the pedal to feel rock hard. When it does, it'll stay rock hard with very acceptable pedal travel but next morning the pedal travel has increased and the action feels spongy. However, there are no leaks anywhere and the car brakes very well with no problems. Also If the pedal stays hard with little travel it's because one of the boosters is hanging up. But I've also found out that if the pedal feels spongy or has more pedal travel than acceptable then it's quite possibly one of the wheels brakesthat is locked up . It's quite possible that the M/C could have been replaced with a Lancia one which is identical in appearance and dimension but the rear pump is 7/8 (been there, when I was sold a brand new M/C for the S1).

I know how frustrating this can get. Wish you luck!

Yves
DWR46
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Re: SI 330 Brake Master Cylinder

Post by DWR46 »

Tom: The Series 1 330 GT cars were built with 1" Fiat master cylinders. When the "hanging pedals" came in , they switched to 7/8" Dunlop master cylinders. My source is dozens of factory build sheets (they are all consistent).
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tyang
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Re: SI 330 Brake Master Cylinder

Post by tyang »

Thanks Yves and Dyke,

I'll let you know what I find on this car.

Tom
'63 330 America #5053
tim
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Re: SI 330 Brake Master Cylinder

Post by tim »

Greetings… Mine is one inch as well. Getting a consistent and firm pedal is an art form. Allow a day and lots of brake juice as well as patience.


Tim
1964 330GT 5769 -the big yellow taxi 61&66 Morgan +4's Daimler SP250 Turner 950S and some other dull stuff plus a brand Mercedes C300 4matic
jagpartsman
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Re: SI 330 Brake Master Cylinder

Post by jagpartsman »

Tom:

If it turns out to be a Dunlop, let me know as I probably have the correct kit and maybe even a spare body and/or complete cylinder. Just get me the Dunlop number cast into the body. We won't tell anyone that it came from a lowly Jaguar ...

Michael
XKs Unlimited, SLO, CA
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tyang
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Re: SI 330 Brake Master Cylinder

Post by tyang »

OK. It's a 1-inch bore on this master cylinder, so that's not the reason for the spongy pedal.

I'm going to keep trying to figure out what the problem is. Stay tuned!

Tom
'63 330 America #5053
DWR46
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Re: SI 330 Brake Master Cylinder

Post by DWR46 »

Tom: Does this car have a hydraulic booster on the front crossmember?
Stevie
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Re: SI 330 Brake Master Cylinder

Post by Stevie »

Had the a similar issue on an old Jag. Have thrown out the vacuum bleeder, and in the end started bleeding the old fashioned way with a helper on the pedal. The trick for me was to bleed with the engine running, so there's vacuum on the booster. Can't explain why, even with booster replacement and rebuild of every single other component it will only get properly bled with vacuum on the booster... Perhaps it helps!
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tyang
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Re: SI 330 Brake Master Cylinder

Post by tyang »

DWR46 wrote:Tom: Does this car have a hydraulic booster on the front crossmember?
Hi Dyke,

No it does not. For the SI 330s, Ferrari eliminated the hydraulic booster and equalized the brake pistons by varying the caliper piston sizes.

Tom
'63 330 America #5053
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tyang
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Re: SI 330 Brake Master Cylinder

Post by tyang »

Stevie wrote:Had the a similar issue on an old Jag. Have thrown out the vacuum bleeder, and in the end started bleeding the old fashioned way with a helper on the pedal. The trick for me was to bleed with the engine running, so there's vacuum on the booster. Can't explain why, even with booster replacement and rebuild of every single other component it will only get properly bled with vacuum on the booster... Perhaps it helps!
Since I get hard pedal with the boosters eliminated, the problem has to be either in the booster, or in the lines in and out of the booster. If air is getting trapped in the booster, or in the loop of of steel line coming out of the booster, I'm going to have to find a way to bleed these brakes better. I've bled these brakes using the brake pedal, gravity bled them, and reverse bled them without any difference with the spongy pedal. I've sent the master and the booster out to my brake guy for him to take a look, and if he doesn't find anything wrong, I'm going to take a good hard look at if air is getting trapped in the lines.

Tom
'63 330 America #5053
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