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which master cylinder?
-matt - 29/9/10 at 10:59 PM

im after a single master cylinder for my Indy R.

ive noticed some seem to use one off the fiat 124, is this or the standard sierra one best?

im using standard sierra front and rear disks, if that makes any difference.

cheers

Breaker - 29/9/10 at 11:16 PM

Sorry to hijack but interesting topic, I'm also looking for a Indy R master cylinder.

I'll be using 4 pot Wilwood powerlites on the front and standard sierra brakes at the back.

bbwales - 29/9/10 at 11:34 PM

Hi,

I have used this m/cyl on my build http://cgi.ebay.co.uk/Brake-Master-Cylinder-Fiat-Panda-1985-1993-/380087831932?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item587f000d7c

front and rear brakes are Sierra disks, the pedal feels far better than when I used the Sierra m/cyl.

I paid about 25 quid for it though and it was new.

Regards

Bob

[Edited on 29/9/10 by bbwales]

Davegtst - 30/9/10 at 08:05 AM

I've got a fiat 124 on mine. Can't tell you if it is any good yet as the car's not built yet but from a bit of research people seem to say it's the best.

whitestu - 30/9/10 at 08:30 AM

I've had both standard Sierra 22mm MC and Fiat 124 19mm MC.

The Sierra one was OK, and gave a nice firm pedal with little travel, BUT needed a big push to get the brakes to the point of locking up.

With the Fiat MC the pedal moves quite a bit more and is softer, which sitting in the car with it stationary feels worse, but the brakes have more power and are more progressive when on the move.

Stu

Breaker - 30/9/10 at 11:26 AM

quote:
Originally posted by Davegtst
I've got a fiat 124 on mine. Can't tell you if it is any good yet as the car's not built yet but from a bit of research people seem to say it's the best.


Does this Fiat 124 MC also has 2 separate connections for the front brakes and M10 thread ?

-matt - 30/9/10 at 11:43 AM

cheers, i think ill go for the 124 then.

Davegtst - 30/9/10 at 01:45 PM

It's an m10 tread but a different pitch (can't remember what pitch offhand) so the brake pipes from MK won't fit. I had to make up all new copper pipes for mine as all of them were too short or far too long.

whitestu - 30/9/10 at 01:47 PM

quote:

It's an m10 tread but a different pitch


That's right - m10x1.25 I think.

Davegtst - 30/9/10 at 01:53 PM

Sounds about right. Brakes international will sell you the m/c and unions very cheaply and are very helpful too.

Breaker - 30/9/10 at 01:57 PM

quote:
Originally posted by Davegtst
Sounds about right. Brakes international will sell you the m/c and unions very cheaply and are very helpful too.


Perhaps stupid question, but if I look up this part, I only see a picture of the outer part of the master cilinder.

The "piston" (don't know how it's called) that goes inside the cilinder is not on the picture. Do you have to order this separately ?

whitestu - 30/9/10 at 02:18 PM

You just need to make up a pushrod from some 8mm threaded bar. The pistons will be in there somewhere.

You will also need to get a reservoir and suitable tube to connect to the MC though.

My res came from rally designs for about £15

Stu

[Edited on 30/9/10 by whitestu]

[Edited on 30/9/10 by whitestu]

Breaker - 30/9/10 at 02:46 PM

quote:
Originally posted by whitestu
You will also need to get a reservoir and suitable tube to connect to the MC though.


The 2 connections to the reservoir are also M10 x 1.25 ?

whitestu - 30/9/10 at 02:53 PM

No, the reservoir connections are push on rubber pipe so you need pipe that is the right diameter (I think 5/6mm is OK) and resistant to brake fluid.
The master cylinder should come with push plastic connectors that allow rubber feed pipe to be connected.

I had some difficulty getting pipe that was small enough for the master cylinder connections and big enough for the reservoir, but managed to get some off ebay in the end.

Stu

mads - 14/3/11 at 01:48 PM

am in the process of buying the master cylinder for my Indy R. can anyone confirm that the fiat 124 one will be OK with wilwood's? and the reservoir on rally design site, is it this one that I need to get to fit the master cylinder?

and anyone got recommendations for the clevis pin needed on the brake pedal? using MK standard pedals for now.

[Edited on 14/3/11 by mads]

britishtrident - 14/3/11 at 03:18 PM

With Wilwoods you may find you get excess pedal travel with the Fiat m/c --- this is due to the fact that multi pot light alloy callipers are known to flex under hydraulic pressure much more than the standard cast calipers, also Sierra style floating callipers can to an extent self-align with the disc.

You can reduce the pedal movement to a minimum if you make sure the calliper is mounted to present the pads to exactly square to the disc surface, even a tiny degree misalignment will cause a spongey pedal.
A bit of time spent aligning the calipers makes a huge difference.

Also make sure your brake pedal box and its mountings don't flex excessively .

[Edited on 14/3/11 by britishtrident]

britishtrident - 14/3/11 at 03:22 PM

Also don't use copper for brake pipes --- 3/162 Kunnifer is the most suitable DIY material for brake pipe and about the same price as copper.

mads - 14/3/11 at 08:24 PM

thanks for the info. so is there a master cylinder i can use similar to the fiat one that wont cause as much excess pedal travel?

britishtrident - 15/3/11 at 09:53 PM

Early Golf/Polo non-servo master cylinders are availble in bore sizes smaller than the Sierra but bigger than the Fiat, they are also available very cheaply.