95 civic master cylinder replacement

hopefully someone can help - i gotta get to work on monday!
95 EX coupe; replaced Master Cylinder (purchased online), along w/ front'n
rear pads. installed MC according to shop manual, but without checking
pushrod clearance adjustment w/ special tool (which i dont have). filled
w/ fluid and now there is NO pressure in the system. pumped it for
minutes w/ no change. the MC did make a sort of wheeze on release of
pedal. no leaks anywhere - but no pressure. could it be this pushrod
adjustment? HELP!

 

Did you bench bleed it?

 

you can "bench bleed" on the car. loosen one inlet pipe at a time &
have an assistant pump the pedal to the floor to make sure all air is
expelled. wash fluid runoff with plenty of water. /never/ wipe. take
care not to contaminate reservoir with water.

 

You have ***LOTS*** of air in the system. You will need to bleed the brakes
for a LONG time to get all the air out of the system. Keep going, it WILL
eventually firm up. Might take you a half-hour or more. Be patient.

If you have no Mity-Vac or other mechanical aid, get somebody to help by
pushing the pedal for you. Get some 3/16" or 1/4" ID vinyl hose from Home
Depot, a 10mm wrench, and an old jug to catch the fluid in.

Helper: Pump several times, then hold pedal
You: Release bleed screw and close it
Helper: Release pedal
Repeat above for ages, making certain that the MC never runs dry!

Helper will probably have to pick pedal up off floor with toe until
pressure is felt. You will see lots of bubbles and long stretches where no
fluid comes out at all.

Do the right-rear first, then left-front, then left-rear, right-front.

Since the Master Cylinder is new, the pedal-to-the-floor thing is perfectly
safe. If you bleed the brakes annually, it will continue to be safe
forever.

 

Forums are great.
Thanks guys.
No I didn't bench bleed - never heard of that. 1st time doing a MC. I'll
try this suggestion.
So - this pushrod clearance probably was set correctly at the
manufacturer?

 

if the m/c is the same brand as the original, i'd say yes. see how you
go & be aware that there /are/ times when you need to adjust, but in my
experience, that's not often.

 

FYI - You guys are all correct. Lots of air in there. Those brake lines
are pristine now! Too bad I don't own stock in brake fluid...
Thanks again -

 

a thorough flush of all the fluid is a very good thing - don't grudge
those few bucks. an annual flush will keep your system running great
vitually forever.

 

i live in a warmer climate, and go with every 3 years. YMMV.

 

thing is though, brake fluids contain rubber preservatives that help it
retain its structure, flexibility, etc., so it's not just a case of
worrying about water absorption. annual changes are good.

 

Do you have any evidence to demonstrate that annual brake fluid changes
increase the longevity of brake systems?

I know 3k miles engine oil changes also do not hurt and are not expensive.
But I think most people here agree for the typical driver that's way more
oil changes than are necessary.

For the record, the 91 Civic's maintenance schedule dictates brake fluid
changes every 30k miles or 2 years, whichever comes first.

 

good question. i'm going on the advice of a polymer chemist i know and
my subsequent experience of changing my own fluid regularly, but i don't
have hard data for you.