Alternative Brake Master Cylinders -Using Stock Location

[lookforjoe]

Forgot to post this here:

Welded the shaft to the clutch pedal, then put the pedal assembly together, set to center on the bias bar.

Remote adjuster cable attaches here:

Getting a smooth arc for the cable may be an issue with the heater casing

Now I have the front brakes in, I figure it's time to move on this. Problem is, I'm pretty sure the whole thing is too wide for the space. I used the photos in the Swedish guy's pic album as my guide - this is the only one of it in place...

What is evident is that it is right up against the heater box, not a problem I was thinking, I made mine so that it pretty much matches the overall width of the bias box he used. The problem is, my AC box has an external diaphragm mounted in exactly that area, which gives me a 2-3" clearance issue

EDIT: Larry's pic:

Maybe I can just drill out the rivet & pivot the valve up & rearward...

I'm hoping I can move the brake line junctions I made around to clear it, however I may have to remake the lines and move the junctions elsewhere. Pretty sure the physical pedal bracket offset is not an issue.

 

[kmead]

You could convert the box to fully manual control to save space. That could easily become a cable operated object to open and close the air flap.

 

[Dr.Jeff]

Your pedal box project looks great. I like this approach over mounting the masters in the frunk. Nicely done. Are the new shaft and bushing from a machine shop or did you make them? They look really good.

I had the exact same thought as Karl; get rid of the leaky vacuum controls and convert it to cable operated. I will do this to mine, not to gain any clearance, but just to eliminate the problematic vacuum system (I have three of them and they all leak). That will allow you to gain the room you require, plus there will be no need for any vacuum lines/components in the interior of the car (the HVAC control is the only thing that operates by vacuum). I've never found vacuum actuated systems in any vehicle to be reliable over time, and have never cared much for its operation.

As for clearancing the cable control on the brake bias adjuster. How about converting it to a electric solenoid/actuator?

 

[lookforjoe]

Dropped the column so I can do the pedal assembly.

The brown wire (melted socket) was previously cut & soldered (poorly). I will need to address all the column wiring after I get the pedal assembly done.

Disconnected the brake lines and plugged the ports with old brake fitting ends

After some bending of the stock lines and finagling with the brake line junctions, I got it in place.

The rear master cylinder is up tight against the vacuum valve, but not moving it, so I didn't need to make any changes to the HVAC setup

Only major issue is the clutch line adaptor I made - there is no room to fit the existing hard line to it

Made a new adaptor line that loops around, allowing the stock line to be fitted with easy access

Left side fitting will be secured to inner rail - added a M5 rivnut in the rail

right side junctions up against the heater box

Remote adjuster cable fitting, that was a PITA to attach....

Just have to attach the lines to the reserviors then they can be bled

 

[lookforjoe]

Your pedal box project looks great. I like this approach over mounting the masters in the frunk. Nicely done. Are the new shaft and bushing from a machine shop or did you make them? They look really good.

I had the exact same thought as Karl; get rid of the leaky vacuum controls and convert it to cable operated. I will do this to mine, not to gain any clearance, but just to eliminate the problematic vacuum system (I have three of them and they all leak). That will allow you to gain the room you require, plus there will be no need for any vacuum lines/components in the interior of the car (the HVAC control is the only thing that operates by vacuum). I've never found vacuum actuated systems in any vehicle to be reliable over time, and have never cared much for its operation.

As for clearancing the cable control on the brake bias adjuster. How about converting it to a electric solenoid/actuator?

The SS shaft and bushing I had made locally. Materials were cheap, labor was $180, so about $220 to make them.

 

[darwoodious]

What is evident is that it is right up against the heater box, not a problem I was thinking, I made mine so that it pretty much matches the overall width of the bias box he used. The problem is, my AC box has an external diaphragm mounted in exactly that area, which gives me a 2-3" clearance issue

It's the old "10 pounds of $#!+ in a 5 pound bag" problem that is especially easy in an X1/9.

That looks familiar

Also, the Volvo plastic liner cracks me up.

 

[kmead]

As I said on FB: Needs more Volvo!

 

[lookforjoe]

Hitch in the process - the 5/16 hose I had on hand to use for the Volvo MC feed is SAE 30R9 - which is not brake fluid-rated hose. I will have to drop the box one last time & swap it out for some EPDM hose (ordered) tomorrow or Tuesday. The 1/4" stuff used for everything else won't stretch enough to fit the feed barb.

 

[kmead]

Doh!

 

[lookforjoe]

Dropped the pedal assy., and swapped out the clutch reservior hose for a section of EPDM - C30 coolant reservoir hose, it's 8mm ID

Removing the gates hose

After that, I put back together, fitted the reserviors and bled the lines & MC's. Brake pedal has never felt so firm!

 

[Dr.Jeff]

Brake pedal has never felt so firm!

Nice.
How does the bore diameters for the two new brake masters compare to that of the old stock one? And remind me what calipers you have installed. I'm just trying to get an idea of the relative changes from stock to how it is now.

 

[lookforjoe]

Nice.
How does the bore diameters for the two new brake masters compare to that of the old stock one? And remind me what calipers you have installed. I'm just trying to get an idea of the relative changes from stock to how it is now.

The two new ones are both 3/4" bore, I think the stock MC is also 3/4". I actually don't know the spec of the 6 piston calipers, beyond that I only know there are 3 size pistons per side. I emailed them to get the spec. Rotors are 304mm

 

[lookforjoe]

The two new ones are both 3/4" bore, I think the stock MC is also 3/4". I actually don't know the spec of the 6 piston calipers, beyond that I only know there are 3 size pistons per side. I emailed them to get the spec. Rotors are 304mm

Front calipers have 3 sizes of pistons: 36, 32, 28mm.

 

[Dr.Jeff]

Nice, keeps the pads properly seated as the pressure is applied, good pedal feel, and less chance of squealing.

But really no way to compare the masters' and calipers' bores relative to anything stock. I was hoping to get some feedback on how the pedal travel and feel is with respect to going to larger calipers and a stock master (hope that makes sense).

 

[lookforjoe]

Nice, keeps the pads properly seated as the pressure is applied, good pedal feel, and less chance of squealing.

But really no way to compare the masters' and calipers' bores relative to anything stock. I was hoping to get some feedback on how the pedal travel and feel is with respect to going to larger calipers and a stock master (hope that makes sense).

With the stock master and Prima fronts/larger Fiat rears the pedal felt normal.

After I put the CEIKA brakes in I bled them & the pedal felt softer and further down, so I didn't bother driving it around (before moving on with the MC conversion) to see if it would improve, it just didn't feel good.

 

[Dr.Jeff]

After I put the CEIKA brakes in I bled them & the pedal felt softer and further down

That makes sense with larger hydraulic volume at the calipers. I guess the Prima/larger rears were not enough of a difference in piston diameter/stroke to make a noticeable change.