Alternative Brake Master Cylinders -Using Stock Location

lookforjoe

True Classic
Since I have to drop the pedal bracket again to either mod my clutch pedal lever or install the Volvo clutch master, I'm considering replacing the stock brake master with something of a newer design/construction.

Can't find any specific examples of this, I know we have had the discussion in various threads though.

Any suggestions?
 
Since I have to drop the pedal bracket again to either mod my clutch pedal lever or install the Volvo clutch master, I'm considering replacing the stock brake master with something of a newer design/construction.

Can't find any specific examples of this, I know we have had the discussion in various threads though.

Any suggestions?

Have a look at this guy did:

https://photos.app.goo.gl/NfNJKwZiKjDExWdC8

Cheers,
Dom.
 
If it was me, I'd go the extra effort to get the master cylinders in the front trunk and be done with all that under-the-dash silliness. Has anyone compared a 124 pedal/steering column support to the one in the X, the look rather similar.
 
Thanks for the link - I had forgotten about that car. One master for each circuit seems like a reasonable way to deal with it. No way around that level of fabrication I suppose. Problem with wilwood is the fittings are all standard, last time I looked.

20190520_225224.jpg
 
I know we have had the discussion in various threads though.
However I don't recall that anyone has actually replaced the stock MC with a different one, at least not in the stock position.

If you used a single MC, then it seems fairly easy to add a plate to the pedal box for mounting. Perhaps something along these lines (red=plate, yellow=weld), with holes to match the new MC:
Brake.jpg

Regardless of single or dual MC, I don't see how the fittings will be an issue. Just make new lines with the appropriate fittings on either end to match the new MC and stock remaining system (e.g. the copper lines in the pic you posted).
 
Relocating them in the frunk definitely has benefits. Including the potential to add a booster if desired. However I imagine it would be difficult to do it and still be able to mount the top in the frunk?

I'd like to see the stock MC replaced one way or the other, so we can have more size options to go with big calipers. Should be pretty straight forward with your skills Huss. ;)

What are you doing with the clutch MC?
 
As long as the tubing is the same, does it really matter what is on each end of it? With good materials the tubing will last a long time. The fact that there is a junction block that is the intermediary to the rest of the Fiat connections means you needn’t worry overmuch about SAE or Metric.

Given the fine manner in which Hussein used a Volvo clutch master to replace the Fiat one suggests he might well be capable of adapting some other 19mm master. Crafty one that is. It’d be a shame not to try... He is English you know.

I do like the balance bar twin MC set up, likely to be a replacement part of high quality until the end of fossil fuels. An X MC being available that long? Hardly likely.
 
Relocating them in the frunk definitely has benefits. Including the potential to add a booster if desired. However I imagine it would be difficult to do it and still be able to mount the top in the frunk?

I'd like to see the stock MC replaced one way or the other, so we can have more size options to go with big calipers. Should be pretty straight forward with your skills Huss. ;)

What are you doing with the clutch MC?

As Karl mentioned, I have fitted a Volvo part (to the spare pedal bracket, not installed yet) :D

IMG-20191030-164949.jpg


made a line fitting that goes from Fiat to Volvo. I really don't want to mess with line adaptors or making new lines, that part I hate.
IMG-20191030-164745.jpg


 
Looks like the options (in 3/4") from Wilwood are:

screenshot-www.wilwood.com-2020.01.22-09_22_19.png
screenshot-www.wilwood.com-2020.01.22-09_24_12.png


The only tandem they have that looks like it would 'fit' has a smaller bore (15.875 vs. 19mm) - that would increase pressure, no? Or just desired affect pedal stroke ? Would be much simpler to use a tandem if I can...

screenshot-www.wilwood.com-2020.01.22-09_29_58.png
 
I have fitted a Volvo part (to the spare pedal bracket, not installed yet)
Great job. That is exactly what I was thinking with a replacement (non-Fiat) master brake cylinder in my earlier post.


The only tandem they have that looks like it would 'fit' has a smaller bore (15.875 vs. 19mm)
Regarding dual brake masters. With two of them, the total effective stroke volume (bore size) is for two, not one cylinder. So the size of them will reflect that compared to one cylinder. Also each one may be different, to match the requirements of the front vs rear circuits. But naturally the balance bar also effects that difference. Hence all that math. ;)
Maybe consider one brake master with a proportioning valve instead? Same result for a street vehicle.
 
Great job. That is exactly what I was thinking with a replacement (non-Fiat) master brake cylinder in my earlier post.



Regarding dual brake masters. With two of them, the total effective stroke volume (bore size) is for two, not one cylinder. So the size of them will reflect that compared to one cylinder. Also each one may be different, to match the requirements of the front vs rear circuits. But naturally the balance bar also effects that difference. Hence all that math. ;)
Maybe consider one brake master with a proportioning valve instead? Same result for a street vehicle.

I'd really rther stick with a single tandem MC - if the smaller bore unit would work, I'd go with that.
 
a single tandem MC
Ahhh, earlier when you said "tandem" my mind thought two MC's side by side, like the other person did.

Agree, a single unit will be much easier to configure on the pedal box than a pair of them. And a bias valve can still help balance the front/rear ratio with a tandem MC.
 
You could go with a standard 124 MC that just mounts at the one end like most MCs, they are also a 3/4 bore with an option to go to the 124 Volumex MC which is 7/8

The configuration of ports is quite similar to the X and uses the Fiat sized fasteners for the piping.
 
Still back & forth on this . I was now thinking of the Tandem with bias valve setup - in part because the bias valve has the two outlets that will feed the split front circuits, currently handled by the stock 3 port outlet design of our master. The dual master setup linked in the first response has no evidence of how the split front circuit is handled. Also can't find any sources for balance bar parts that are not really generic, certainly not like the parts he/she used.

Need to take some measurements up in there & see what might fit

X19-0084.jpeg
X19-0084e.jpeg


EDIT; went ahead & ordered a pair of the compact single masters & the balance bar / remote adjuster parts. some of the items were 1/2 price on Amazon, with damaged packaging, so I figured WTH. I'll reference the pics from the linked build & figure it out

260-15091 MC
340-4990 remote
340-1757 balance bar kit

EDIT: Balance bar adjustment settings


:D
 
Last edited:
Just thinking outside the box here. Any room for floor mounted pedals, aka Alfa 4C???

I dunno. That would require re-engineering everything, though. I want to use the stock assembly as my base so only the on-assembly brake lines need revision.
 
Back
Top