Master Cylinder rebuild kits

www.superformance.co.uk has one for about $40.00 Might be worth a look before the dollar devalues against the pound some more, making it $50.00.

http://www.superformance.co.uk/a-246/brakes.htm

DM

 

Bill, I did my Dino master cylinder 2 months ago using a kit from G.T. Car Parts in Phoenix, 623-780-2200 Worked beautifully . . . $14.72 with shipping. Contains just the 3 seals. Cheapest Ferrari part I've ever bought, except for the ashtry light bulb I bought yesterday . . . two for $2.52.

Here's a photo I took during the rebuild that might help anyone who is thinking about doing this.

Bill
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I think I sent mine out during the restoration because folks like White Post and Stainless Steel Brakes also can bore and sleeve them if they are really in need of TLC.

Just a thought.

...Keith

 

So right about the pitting! If you've been flushing the brake system at least every other year, your master cylinder and calipers will be like new when you disassemble them. If you haven't flushed regularly, check carefully for corrosion. If in doubt, resleeve. You don't want to do the master cylinder twice. Bleeding a master cylinder is part art, part science and it's not particularly accessible on the Dino. I was fortunate . . . 66,000+ mile seals were in excellent shape and so was the bore.

Have at it and good luck,

Bill

 

This kit seems to be identical to the 308 kit as does the internals of the master cylinder as illustrated in the pic above.The 4th larger seal goes at the very front shown on the diagram to the left or the side that enters the booster and is held there with the larger washer and the spring clip.

 

Thanks for the info re. vendors (and photos). It appears the master cly on late Dinos had a different bore diameter, as they seem to be the easier ones to rebild. Anyone know the m/c bore dia's for early and late cars? Any hope getting seal kits for the early cars?

 

nothing substantiated but I'd heard Dennison didn't care for White Post's work.

 

I sent my booster to White Post when it went out and they did fine by me.

Jim

 

I purchased a new master cylinder from GT and installed it. Had a huge problem as when things warmed up, the pedal became harder to depress and then not at all as all 4 wheels locked up. Suspected a problem with the new master. We took it out today and measured the inside of the bore for the old and new. The old bore was 2.185" deep while the new one was only 2" deep. A difference of almost 0.200" is way too much to adjust for and we have determined that the differences in length were causing the fluid pressure to build up and, hence, lock up the brakes.

I was simply going to call GT and get the part exchanged but perhaps the problem is one of a newer Dino versus an older one. Mine is a '74, #07966. My concern is that GT will just send another one with the incorrect bore depth again. Thoughts???

 

That doesn't make sense; the volume of fluid in the m-cylinder increases with the greater depth in the master cylinder, but it's the diameter of the m/cylinder bore which changes the amount of brake fluid being moved for a given stroke, and a larger diameter master cylinder will require more force to push, but the stroke will be less.

I'd be looking elsewhere for the problem, such as the internal assembly of the master cylinder and it's relationship to the brake booster.

M

 

wrxmike,

Me thinks I wrote that incorrectly

 

About 5-6 years ago in the old British car world, some people reported problems with White Post's work and started using http://www.brakecylinder.com/ for their brake work, they have done all my work since then and I have never had a complaint.

Scott, I could have shown you their work when you were here if you had asked.

Now, I feel the need to say that 5-6 is plenty of time to fix any problems, so perhaps White Post is back to the quality they had before that but from what I hear they are still inconsistent.

 

The top bolts the one on the right has an extesion piece on it, mine did not have this, is it important and what is it?also the 2 bolts are of different lenghts which goes where?

 

Just checked dino e website and its called a hollow screw with pin,what does it do and is it necessary?

 

Hello Bill,

I am new to the chat line and 246 cars period. I am wondering what year of 911 brake caliper kit your referring to so I can buy them for future use.

Dean
'70 246GT Euro delivery - Coming soon!

 

Im having same problem ( all 4 wheels locked up)did you finally sort it out?