This is the second and final installation of my S2 Festiva M/C conversion project. Although installed on my S2, it has not been road tested. I do however expect the same braking performance as the Courier M/C which was road tested since both master cylinders are very similar in parameters. Due to space limitations of the forum, this is a shortened version of my article. The full piece can be read on my Dropbox account.
https://www.dropbox.com/s/yd5dq6i0mdzrxt4/Adapting%20a%20Ford%20Festiva%20master%20cylinder%20to%20a%20S2%20-%20Fabrication%20-%20Copy%20%282%29.odt?dl=0Adapting a Ford Festiva master cylinder to a S2 - Part 2: Installation
Part 1 of the Festiva master cylinder fabrication section described how to set up the rough initial freeplay for the brake pedal pushrod prior to installing the M/C/linkage box assembly to the S2. Part 2 gives additional information for setting up the linkage for freeplay for final installation of the master cylinder.
There is no freeplay specified for the Europa in the servce manual. The reason I believe is that the freeplay gap is fixed in the design of the Girling master cylinder pushrod system. The mushroom head of the pushrod is captured by a dished washer and “C” clip against the rear of the primary piston with a matching concave configuration. The small gap between the two is the fixed freeplay of the OEM system. This gap, as best as I could measure, is around 0.05”- 0.07” and is the reference freeplay I was seeking to achieve with the Festiva master cylinder (Pic 1).
Setting final freeplay/installation
• Part 1 sets up the linkage to get the freeplay very close in the ballpark. Confirming final pedal freeplay should be done with the extension box and master cylinder be installed, attached and tested with the brake pedal.
• The overall length of the master cylinder pushrod/clevis assembly is critical. There is a relatively narrow range of length that will work with the Festiva M/C to allow minimal freeplay and still allow full travel of the primary piston of the M/C. The maximum overall master cylinder pushrod clevis assembly length should be less than 4.65” from the end of the push rod tip to the centerline of the clevis pivot hole. Anything longer will give zero to negative clearance (Pic 2).
• Besides the maximum overall length, there is one other length that is critical. The threaded part of the pushrod that screws into the clevis must be at least 2.3” long in order to have the nose or tip of the clevis clear the retaining “C” clip at the end of the master cylinder on full travel of the brake pedal during brake bleeding (Pic 3).
• Clevis length will vary depending on the supplier. At full travel, ensure that the threaded pushrod is long enough such that the tip or nose the clevis does not contact the “C” clip and possible knock it out of position causing brake failure.
• Using my master cylinder pushrod/clevis as reference, an overall length of approximately 4.60” gives a freeplay clearance of 0.06” with only the inch and a half diameter stop washer. No other adjustment washers were necessary.
• Screw on the brake pedal pushrod about halfway on it's clevis and install the linkage box and M/C to the “T” section of the frame. My initial pushrod position was set at about 20 turns in as a starting point. I only needed to change the pushrod position about 2 to 3 turns in to adjust it to my liking..
• With the brake pedal secured to the pushrod, confirm correct pedal freeplay. If you measured the clearance correctly at bullet point 4, no further adjustment should be necessary. If however any change to correct freeplay is needed, then remove the linkage box/master cylinder assembly from the car and make the appropriate adjustments and re-install and re-check.
• In my case , the initial ballpark setup was satisfactory so no changes to the linkage was required. Your experience or your preference may be different.
• Last step after setting final freeplay is to remove the linkage box assembly one last time to locktite the M/C pushrod and the freeplay washer jam nut if not using lock nuts. Reinstall the linkage box assembly locktite the four retaining bolts to the backing plate.
Installing the brake lines
As with the stock Girling master cylinder, there is fairly tight clearance between the spare tire and the Festiva master cylinder, approximately 1-1/2” . The stock Girling M/C uses banjo fittings probably for this reason and is a good reason to continue using this system. However, I've put forth a few alternate options if the stock banjos are not available.
• The cheapest and most obvious option is to reuse the stock OEM brake lines and banjos and tweak the existing lines to match the Festiva ports (Pic 4,5). Using this option runs into the same issues as with the Courier master cylinder conversion. The Festiva M/C having a straight bore uses 10mm x 1.0 banjo bolts for both ports. The Girling banjo hole is 0.44"/11.22mm in diameter while the 10mm bolt is 0.391"/9.93mm wide which makes for a moderately sloppy fit. It's up the owner to determine if the slightly loose fit is acceptable as is but the use of a sleeve to reduce the slop is recommended. I've documented the fabrication of the sleeve in another article “Using the 10mm banjo bolt with the Girling Banjo”.
• The second and next easier option is to eliminate the banjos at the M/C and run all new hard lines and fittings directly to the M/C. New fittings required are two 3/8-24 male tube nuts and bubble flares at the bulkhead junction (same as stock) and two M10x1.0 male tube nuts with double flares at the master cylinder end (Pic 6,7). The difficulty with this option is in making the bends at the master cylinder tight enough to clear the spare tire without kinking the hard line. It is possible if care is taken, I chose this option for the Courier M/C conversion (Pic 8,9).
• The third and more expensive option is to use all new metric hardware and banjos. Unfortunately with this option you may be restricted to using banjos with 37 degree AN/JIC flares which are incompatible with the more common SAE 45 degree automotive brake double flares. This will require buying a 37 degree flare tool or having a brake shop flare the line. AN specific tube nuts and sleeves are also required along with two 10mm x1.0 banjo bolts (Pic 10,11). Fittings at the bulkhead junction remain the same, 3/8-24 male tube nut fittings. This is the option I chose to use.
• The most expensive and complicated option uses flexible S/S braided lines with -3 female AN fittings and 10mm banjo adapters to connect to the Festiva master cylinder (Pic 12). I have not explored this option in any great detail so there may be additional fittings required to make this option work.
With lines installed, final step is to bleed the braking system and reinstall all pieces removed earlier.
Finally, I would like to reiterate that I am not an engineer and that this brake actuation system does deviate from original design. Common sense and care in workmanship needs to be paramount when working on and modifying the braking system. Ensure that adequate freeplay and movement is present and eliminate all binding in the linkage system prior to testing on the road.
Joji Tokumoto
Rev 0
Jan//2019
