bad brake booster in 71 sedan?

dana · Post by **dana** » Sat May 13, 2006 9:50 am

Here is what I have happening:
1. I have to refill the brake fluid about 1 time per month. No brake
leaks on any wheels or master cylinder visible.
2. when I push on the brake, the engine speeds up slightly, when I
let off, it drops back down.
since I rebuilt the back cylinders and bled the fronts, I am making
the assumption that the vacuum booster is leaking when I press on
the brakes. Anyone have an opinion?
here is the real question: what happens if I plug off the vacuum
line, how bad will the brakes get? Does anyone have any idea what I
am likely to find if I dismantle the booster? if the rubber has a
hole in it, can I use something like you patch bike tires (with the
vulcanizing step) to fix it? Or will it be melted and not be
reassemblable (pardon the new word)?
I also figure its contaminating the engine oil as it is probably
getting sucked out. But with a refill per month, it cannot be real
bad (thats maybe 2 or 3 oz per month that is disappearing).
If I block the vacuum line off, will the master cylinder still have
a leak or will it stop since it will no longer be subjected to a
vacuum?
Richard

Steve · Post by **Steve** » Sun May 14, 2006 12:01 pm

I rebuild brake boosters. You can attempt to fix yours but there are
no parts, I don't even have parts anymore. The rear seal has leaked
into the canister, likely your large diaphragm has become distorted.
After awhile fluid will get sucked into the engine.
The last price I charged to do a booster was $350.00. You can re
reroute your brake line directly to the master cylinder and
disconnect the vac line. I tried to get seals made but there was a
500 piece minimum per seal type with aprox $5000 charge. I did have
the smaller pistons remade and found a 9/16" seal to sub for the end
seal and have done some other things, but without the other large
diaphragms which actually do the work, it's a worthless effort.
Miles

dawn_and_darrian · Post by **dawn_and_darrian** » Sun May 14, 2006 12:04 pm

Miles,
Just curious to know if you have toyed with the idea of using a brake
booster from another year civic or cvcc.
I'm unsure if it would fit or not, but it might be worth a try.

Steve · Post by **Steve** » Sun May 14, 2006 12:14 pm

Brake boosters from civics, like most other cars are mounted directly
to the master cylinder. Not sure how that would work. Would need one
from some other car which is mounted remotely like the Honda 600.
Miles

dana · Post by **dana** » Sun May 14, 2006 4:35 pm

Message
If I reroute the brake line how bad are the brakes? As it is, they aren't great, but about as good as any 600 I have ever had. I bought the double female coupling yesterday to put the two lines together OR is it just easier to bend the one line after taking it off the booster and putting it in the master cylinder?
I was a little worried about kinking or breaking it.
Richard Morris

> -----Original Message-----
> From:
> 2cylinderhondas@yahoogroups.com [mailto:2cylinderhondas@yahoogroups.com] > On > Behalf Of > Miles Chappell > Sent:
> Sunday, May 14, 2006 2:02
> PM
> To:
> 2cylinderhondas@yahoogroups.com
> Subject:
> [2cylinderhondas] Re: bad brake booster in 71 sedan?
> I
> rebuild brake boosters. You can attempt to fix yours but there are > no > parts, I don't even have parts anymore. The rear seal has leaked > into the > canister, likely your large diaphragm has become distorted.
> After awhile
> fluid will get sucked into the engine.
> The last price I charged to do a
> booster was $350.00. You can re
> reroute your brake line directly to the
> master cylinder and
> disconnect the vac line. I tried to get seals made but
> there was a
> 500 piece minimum per seal type with aprox $5000 charge. I did > have > the smaller pistons remade and found a 9/16" seal to sub for the end
> seal and have done some other things, but without the other large
> diaphragms which actually do the work, it's a worthless effort.
> Miles
> --- In 2cylinderhondas@yahoogroups.com, "Richard
> Morris"
> wrote:
> > Here is what I
> have happening:
> > 1. I have to refill the brake fluid about 1 time per
> month. No brake
> > leaks on any wheels or master cylinder
> visible.
> > 2. when I push on the brake, the engine speeds up slightly, > when I > > let off, it drops back down.
> > since I rebuilt
> the back cylinders and bled the fronts, I am making
> > the assumption
> that the vacuum booster is leaking when I press on
> > the brakes.
> Anyone have an opinion?
> > here is the real question: what
> happens if I plug off the vacuum
> > line, how bad will the brakes get?
> Does anyone have any idea what I
> > am likely to find if I dismantle the
> booster? if the rubber has a
> > hole in it, can I use something like you
> patch bike tires (with the
> > vulcanizing step) to fix it? Or will it be
> melted and not be
> > reassemblable (pardon the new word)?
> > I also figure its contaminating the engine oil as it is
> probably
> > getting sucked out. But with a refill per month, it cannot be > real > > bad (thats maybe 2 or 3 oz per month that is > disappearing).
> > If I block the vacuum line off, will the
> master cylinder still have
> > a leak or will it stop since it will no
> longer be subjected to a
> > vacuum?
> Richard

friend · Post by **friend** » Sun May 14, 2006 7:39 pm

Hi Matt;
I looked through my list of owners and didn't see your 71 Sedan listed. If
you could send the Chassis, Engine and date of manufacture I might have a
rebuildable Sedan cast iron booster. The cast iron boosters can still be
rebuilt if (like Miles says) the diaphragm is still good.
Bill

G.Bertolin · Post by **G.Bertolin** » Mon May 15, 2006 6:49 am

victoria british sells a remote vacuum booster for a
sunbeam alpine. one line in and one line out.
walt
--- Miles Chappell wrote:

> Brake boosters from civics, like most other cars are
> mounted directly
> to the master cylinder. Not sure how that would
> work. Would need one
> from some other car which is mounted remotely like
> the Honda 600.
> Miles
> --- In
2cylinderhondas@yahoogroups.com
, "Matt
> Timion"
> wrote:
> > Miles,
> > Just curious to know if you have toyed with the
> idea of using a
> brake
> > booster from another year civic or cvcc.
> > I'm unsure if it would fit or not, but it might be
> worth a try.
> > ----- Original Message -----
> > From: "Miles Chappell"
> > To: > Sent: Sunday, May 14, 2006 12:01 PM
> > Subject: [2cylinderhondas] Re: bad brake booster
> in 71 sedan?
> > >I rebuild brake boosters. You can attempt to fix
> yours but there
> are
> > > no parts, I don't even have parts anymore. The
> rear seal has
> leaked
> > > into the canister, likely your large diaphragm
> has become
> distorted.
> > > After awhile fluid will get sucked into the
> engine.
> > > The last price I charged to do a booster was
> $350.00. You can re
> > > reroute your brake line directly to the master
> cylinder and
> > > disconnect the vac line. I tried to get seals
> made but there was a
> > > 500 piece minimum per seal type with aprox $5000
> charge. I did
> have
> > > the smaller pistons remade and found a 9/16"
> seal to sub for the
> end
> > > seal and have done some other things, but
> without the other large
> > > diaphragms which actually do the work, it's a
> worthless effort.
> > > Miles
> > > --- In
2cylinderhondas@yahoogroups.com
, "Richard
> Morris"
> > > wrote:
> > >> Here is what I have happening:
> > >> 1. I have to refill the brake fluid about 1
> time per month. No
> brake
> > >> leaks on any wheels or master cylinder visible.
> > >> 2. when I push on the brake, the engine speeds
> up slightly, when
> I
> > >> let off, it drops back down.
> > >> since I rebuilt the back cylinders and bled the
> fronts, I am
> making
> > >> the assumption that the vacuum booster is
> leaking when I press on
> > >> the brakes. Anyone have an opinion?
> > >> here is the real question: what happens if I
> plug off the vacuum
> > >> line, how bad will the brakes get? Does anyone
> have any idea
> what I
> > >> am likely to find if I dismantle the booster?
> if the rubber has a
> > >> hole in it, can I use something like you patch
> bike tires (with
> the
> > >> vulcanizing step) to fix it? Or will it be
> melted and not be
> > >> reassemblable (pardon the new word)?
> > >> I also figure its contaminating the engine oil
> as it is probably
> > >> getting sucked out. But with a refill per
> month, it cannot be
> real
> > >> bad (thats maybe 2 or 3 oz per month that is
> disappearing).
> > >> If I block the vacuum line off, will the master
> cylinder still
> have
> > >> a leak or will it stop since it will no longer
> be subjected to a
> > >> vacuum?
> > >> Richard

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friend · Post by **friend** » Mon May 15, 2006 11:10 pm

Do they have a web site?

isettajoe · Post by **isettajoe** » Tue May 16, 2006 2:26 pm

The fellow who redid my sedan engine and brakes used a brake master
cylinder from an 83 Civic and scrapped the booster. The unit fits
thru the firewall fine, and only needed some mounting holes
enlarged. It has plenty of stopping power. He has done this on his
2 sedans too.

friend · Post by **friend** » Tue May 16, 2006 11:00 pm

It sounds like a great mod, did the push rod have to be replaced?
Bill