Thanks for the reply, Richard.
Regarding the option of adjusting the pedal pushrod length, yep, have been
working on this, adjusting a little at a time to take it as far as possible
before brakes start to drag. Every little bit has helped here, as the pedal
pivot ratio is so high.
None the less, at the end of this there's still going to be more free play
at the foot pedal than I'm accustomed to in other cars, such as Alfa Sud
Sprints and TI's, Alfa 156, and any 70s or 80s Japanese car I've ever
driven. There's not a huge amount, just a lot more than the above cars which
have very little. I've prodded a number of other people's GTV brake pedals
over the years when I've had the opportunity, and I must say I've only ever
felt one that I thought felt really good, so I've wondered if it's a case
of, "They all do that Sir", or if they can indeed be much better when
everything is in good order.
In terms of pad clearance, don't think this is an issue as I can hear the
pads lightly and evenly brushing the discs when I spin the wheels to check
for brake drag. However I could make a more thorough check by removing the
wheels and the pad retainers and then checking for clearance by hand. The
calipers have all been cleaned out and new seals fitted, by the way. And in
case you might ask, I don't think possible disc runout is my problem, as the
longish pedal occurs even when just parked in the garage, and doesn't get
any worse when the wheels are turning (either on jacks or on a test drive).
Also re your note on clearance, unfortunately the car's not ready for road
warrant and licensing yet, so I can't go out on the main road to really make
the brakes work hard as you suggest. (So far, can only test-drive it on the
local village streets and hills away from the eyes of the law.)
And on clearance again, we don't need to worry about the reverse bias 'cos
I've removed that in the meanwhile - I may or not refit after I've got round
to refurbishing the barnacled old thing.
Lastly on clearance, when I was rebuilding the rear calipers, I encountered
for the first time the funky clearance-takeup mechanism these cars have on
the rears, and that seemed to be working correctly, so there should be no
clearance-problem on the rear pads.
Brake hoses - look OK, but certainly not new. Renewing these could give a
firmer pedal under load but I don't feel they're applicable to the initial
free play I've got before the pedal actually reaches the point of applying
any real load.
Brake bleeding - seemed to bleed up pretty well. I think further bleeding
could give a firmer pedal under load but (as per above) I don't suppose it's
an issue for the initial free play before the pedal takes on a load.
Master cyl - have pulled that apart - it looked very shiny inside, so
cleaned it well, fitted all new seals.
In-line boosters - have removed and bypassed the rear one, and rebuilt the
front one only. It works fine. I've tried the brakes with it and without it
in the circuit, and the free play doesn't change, so I don't think the
boosters are an issue here.
Well - what do you reckon? What to do next?
Best regards, and many thanks,
Graham Hilder,
Paekak NZ, 1750 GTV.
(PS My word, that's a fine collection of Alfas you've got Richard!)
-------- Original message ----------
From: "Richard Jones" <[email protected]>
Subject: [alfa] Underfloor GTV Brake MC sizes
If eliminating pedal play before bite is what you are trying to
achieve Graham you can adjust the length of the pedal actuating rod. Just
make
sure adjustment is done in reasonably small increments as you can interfere
with the piston travel return which won`t alloy the master cylinder to draw
in
sufficient fluid from its ports.
My experience has been that if set up right there isn`t really a great deal
of
pedal movement in this RHD setup and if there is I would be meticulously
examining why. Just make sure the pad to disc clearance is right before you
do
anything else-go out and use the brakes really hard PLUS use them really
hard
a few times in reverse so that brake bias is changed to the rears-recommend
to
do at least once a week if the car is used regularly. How old are the hoses?
Is the MC ok? once you have good pad to disc clearance you can then progress
to these other possibles.
Alfa brakes for a std car are pretty well specced and operate ok so test the
system you have first and get that right-I`ve seen too many buggered about
cars just because people overlooked the obvious.
Richard Jones (Alfavirusnz)
ChCh NZ
<<<<<<<<<<<<<<<<<<<<
--
to be removed from alfa, see http://www.digest.net/bin/digest-subs.cgi
or email "unsubscribe alfa" to [email protected]
