After I replaced the brake pedal housing bushings / springs I reinstalled unit and ended up with significantly higher brake pedal height relative to adjacent clutch pedal. How can I adjust brake pedal to be even height with clutch pedal? I researched our forum posts and Jerry noted the 4.2 does not share the brake pedal splined shaft of 3.8. So can if I loosened large housing nut and somehow tapped what-looks-like eccentric shaft outward, rotate, and then tighten bolt to affect brake pedal height.
Patrick I don’t recall that that shaft is eccentric… I’ve had it in and out numerous times and have never had to adjust it. Important question - is there a lot of free play when you depress the pedal. There is an adjusting bolt on the aluminum housing and is used to adjust pedal height. It faces the firewall. However - even after adjusting it you must have some free play in the pedal. The system is designed that the push rod has to be at the extreme end of it’s outward travel - it’s retained in the m/c -so when properly adjusted you can still pull the pedal back a small amount. I must say - something looks seriously screwed up.
Geo and Terry, I adjusted free play bolt CW tighter and that decreased free play but did lower brake pedal to almost level with adjacent clutch pedal, however now brakes are tight. So I CCW said bolt and got some free play, brakes released, but now brake pedal again sits too high. I thought the shaft was eccentric due it’s a out of round end of shaft.
I don’t think a spring could cause this (either a pedal spring or the M/C spring…
There is really nothing holding the pushrod in place, it just finds a home in the center of the cup on the back of the M/C spring… but I wonder if the rod can slip out and down so it is catching the lip of the cup instead of being deep in the center of it. Would never happen in operation but with things apart… maybe.
Geo, I visually checked and the rod is ok. I suspect rod however is too long. I wonder if usual sent me the wrong Brake Master? Tomorrow I’ll look and see if brake rod yoke end is adjustable or maybe the brake lever has another hole for rod optional placement. It’s something I have to fix though as in a panic stop I don’t want to be searching for the freaking brake pedal.
Spent hours looking through JL posts and early 4.2 had brake shaft splines for purposes of positioning the brake pedal on its shaft for best heel and toe. But my '66 has no splines, just the solid shaft, plastic bushings, spring and that protruding free play bolt. One poster noted a pin for positioning brake pedal height, I looked and other than the free play bolt there is no pin. I don’t recall if rod ball is locked in place within BM , if not I could remove rod lever pin insitu and try and find a shorter rod version.
Patrick You may not be able to get these two pedals exactly equal. My brake pedal typically sits a little higher than the clutch. Your photo shows it’s way too high, but the difference is difficult to discern in a photo. Your issue is most certainly the fitting of the m/c and rod, but there is no adjustment there. I’m wondering if the rod is somehow hung up and not in direct contact with the piston, and as a result sticks out too far.
On my S3, I ve got the same problem but with the clutch pedal. A strut missed between the master cylinder and the pedal box.
Dont you face the same issue?
I think I found the problem. Few mos ago another '66 Etyper showed a pic of his separate housings for clutch and brake and his brake pedal could be be positioned on shaft for user friendlier operations via splines and a pinch bolt. His clutch peal box was separate and his clutch pedal adjustment was as often noted by Jerry requiring clutch housing installation shims of correct size to yield his clutch pedal to match his adjacent brake pedal.
But alas, Jaguar in later 1966 model run decided to simplify (cheaper) the whole brake clutch operation(s) by using a single housing for both clutch and brake and gone was early 4.2 “pinch bolt” and “splines”. That left (for later 4.2) just the two pedal forks to control user preference.
A look at the Jaguar “4.2” Parts Books does not show my later 4.2 combo clutch/brake assembly; it only illustrates the early 4.2 separate housings system. So the ‘usual’ sent me an early separate housing brake master; that’s not a problem but it’s freaking fork is for the earlier 4.2 single brake housing and thus I end up with mismatched clutch/brake forks and results in ridicules brake pedal positioning.
Same Blue 4.2 Parts Book shows part number for earlier clutch fork which I have to source to replace the too long later 4.2 brake fork.
Michel, on your S3 I think from reading lots of Jerry posts, he noted that a clutch housing shim could fitted to bring inline the clutch to brake pedal. Am I correct that the S3 uses too separate housings for clutch and brake ? The shims Jerry often noted will affect clutch free play however at it’s clutch master housing.
BTW: Many posts suggest that long adjustment bolt is for positioning purposes, I found it is useful only for free play setting of brake pedal pressure. True, that free-play bolt will move pedal tad direction one way or other, but that affects free play and I ended up with brake full ON (couldn’t turn rotors). So I readjusted bolt for achieve normal free play; but my forks are mismatched lengths and pedal positions are not correct.
Thanks George, I was thinking adjustable rod somehow fit the brake assembly. However, the original rod works for correcting my brake pedal height adjustment.
Took an hour, quite messy, but removed pedal assembly with MB and MC still attached. It might be half ass, but I think I solved my pedal alignment issues.
The ‘usual’ supplied MB had shorter rod than original rod ! But original rod is same length of original clutch rod but with one glaring difference. The 'usual ’ supplied rod, although much shorter, has a “hat” on its ball end while the longer original rod has no “hat” . With the original rod test fitted, I can adjust free play bolt to match clutch position and all is well; and still have required free play as well…
It appears the 'hat" forces the piston in way too soon.
Fascinating, I was wondering how Jerry got his clutch pedal to align where he wanted it. I mistakenly thought Jerry meant the shim went under the housing. From your pictured shim, it looks like the shim actually compensates for wrong rod length ? Because if you change the rod length, making it longer (edit) for your S3, the shim wouldn’t be required. From reading Jerry’s many posts, I think his brake pedal was (splines and pinch bolt) adjustable but his clutch pedal was not.
The push rod for the early 4.2l m/c was C25901, and for the latter one piece aluminum housing C26529, the master cylinder being the same for both. I don’t see a brake m/c shim on the photo from Michael - is he referring to the shim behind the clutch m/c on the right in the photo? I’m not aware of any shims on the later brake m/c’s, and the parts books don’t specify any. Not saying here that you couldn’t use one of course.
Patrick I think that the second push rod in your first photo of push rods is for the clutch slave cylinder.
Terry,
Michael’s shim is on the clutch housing 2 stud spacer that results in correcting rod mismatch.
Pictured here is my original push rod that now allows me to adjust with free play bolt exactly where I want my brake pedal to be positioned. Thankfully I keep all my old original parts. The earlier 4.2 Brake pushrod you noted, C25901 is shorter with a “hat” rod end that doesn’t work for my application as it leaves my brake pedal ridiculously high in footwell.
Patrick
'66 fhc
Pictured my '66 fhc original 4.2 pushrod (top) installed results in matching pedal height; My Christmas present.
