PaulB
11-02-2014, 12:45 PM
This seems to be an issue that pops up from time to time and one that I am currently experiencing. I completed my '33 build (chassis #609) about a month ago - I installed the optional Wilwood brake kit and a hydraulic clutch. I am using the Wilwood pedal box and the Wilwood master cylinders (MC) that came with the kit. I purchased a third Wilwood MC in the aftermarket for the hydraulic clutch slave cylinder and followed the manufacturer's recommendation for bore size. During the build but after go-karting, I noticed hydraulic fluid leaking from the MC for the clutch (mounted on the pedal box closest to the driver's side door). Further examination revealed fluid inside the rubber bellows covering the push rod. Thinking I got unlucky and had a bad MC, I replaced it. After completing the build and putting less than 300 miles on the odometer, I again noticed hydraulic fluid dripping on the pedals and floor, and noticed it was from the MC for the rear brakes (located on the passenger side of the pedal box). I replaced it as well. Now it appears that the (new) clutch MC is once again leaking. The MC for the front brakes (mounted in the center of the pedal box) has so far shown no signs of leakage (knock on wood). The leaks are small with little visible loss of fluids in the three reservoirs, but are of concern should they worsen. The first MC was sent to Wilwood for possible refund but was returned, the Shop Repair Order stating "unit produced leak @ pushrod area disassembled found visible friction marks on piston and severe side loading on inside of bore - unable to repair or rebuild".
The shop order would seem to indicate that the MC pushrod was somehow misaligned and was creating excessive wear when the clutch (and/or brake) pedal was pushed; however, the MC's appear to be straight and aligned on the pedal box (the more I look, the less likely it seems that the MC's could have been installed incorrectly, a view shared by a technician who has looked at this). Before I sacrifice any more MC's, (I have purchased a set of more expensive Tilton's), has anyone else experienced this and know of a solution?
The shop order would seem to indicate that the MC pushrod was somehow misaligned and was creating excessive wear when the clutch (and/or brake) pedal was pushed; however, the MC's appear to be straight and aligned on the pedal box (the more I look, the less likely it seems that the MC's could have been installed incorrectly, a view shared by a technician who has looked at this). Before I sacrifice any more MC's, (I have purchased a set of more expensive Tilton's), has anyone else experienced this and know of a solution?