Servo installation

[Foxie]

Hi listers,

In my search for the perfect brake pedal I submit the following for comment.

I have 2 Plus 2s. There is a Lockheed servo retrofitted fitted in each. In one case the small diaphragm is on the top of the servo cylinder, and the incoming hydraulic connection is on right as one looks at the front of the servo. On the other, the servo has been rotated 90 degrees anticlockwise, so the small diaphragm is on the left side and the incoming hydraulic line is going in to the twelve o'clock position. In the first above the servo cyilinder is horizontal, in the other the nose is tilted up about 10 degrees.

Before I start pulling things apart, has anyone any idea which orientation is correct, or does it matter. I believe it may have an influence on bleeding the system.

Thanks,

Sean Murray

[john.p.clegg]

Sean
my twopenneth
my lockheed servo is horizontal,with the diaphragm uppermost,when i first
got the car i had a problem with the brakes "locking-on",usually at traffic
lights,this was countered by tapping the brake pedal.Conferring with CLASSIC
BRAKE SERVICES a cure was found(known problem),this is the fitting of a
spring in the air valve as fitted in some rover models,anyway since then all
has been well
john
68plus2


-----Original Message-----
From: Sean Murray [mailto:***@***.***
Sent: 09 June 2002 17:07
To: Lotuselan
Subject: [LotusElan.net] Servo installation


Hi listers,

In my search for the perfect brake pedal I submit the following for comment.

I have 2 Plus 2s. There is a Lockheed servo retrofitted fitted in each. In
one case the small diaphragm is on the top of the servo cylinder, and the
incoming hydraulic connection is on right as one looks at the front of the
servo. On the other, the servo has been rotated 90 degrees anticlockwise,
so the small diaphragm is on the left side and the incoming hydraulic line
is going in to the twelve o'clock position. In the first above the servo
cyilinder is horizontal, in the other the nose is tilted up about 10
degrees.

Before I start pulling things apart, has anyone any idea which orientation
is correct, or does it matter. I believe it may have an influence on
bleeding the system.

Thanks,

Sean Murray

[EMA7K]

dear elaners..............
I have a bit of a problem with my brakes and/or servo and wondered if any of
you had experienced similar.....
it goes a bit like this................
drive car......use brakes to stop/slow (brakes fine)........use brakes again
(mush stiffer this time).....
use brakes again (need two feet to stop the car)........brakes are now stuck
on.........drive on and they
release.......
this also occurs when parking up as the brakes will stick on after moving
into parking spot but after
half an hour of so the release...........
my car had had its head lights altered to electric rather than the usual
vacum pods but then had
the vacum pipe from cyl 1 piped into the brake servo vacum from cyl
4......so cyl 1 & 4 were giving
the vacum for the servo......I/we (john clegg) have ammended this back to
running just from cyl 4
and it has made no difference (conclusion being that the vacum from the
cylinders was fine whether
running from 1cylinder or 2)
I have the girling servo and wondered if (as john clegg mentioned) the air
release valve may be the cause..
I have see john's servo but it didnt help much as he has a lockheed
servo.......
what about the master cylinder?
what about the seals in the sevo?
anyone got any ideas...........?
thanks
G

[Elan45]

Replace the hoses at the calipers and check the caliper operation for possible rebuild. Even the newest S4 is 29 years old now.

Rogre



I have a bit of a problem with my brakes and/or servo and wondered if any of
you had experienced similar.....
it goes a bit like this................
drive car......use brakes to stop/slow (brakes fine)........use brakes again
(mush stiffer this time).....
use brakes again (need two feet to stop the car)........brakes are now stuck
on.........drive on and they
release.......
this also occurs when parking up as the brakes will stick on after moving
into parking spot but after
half an hour of so the release...........
my car had had its head lights altered to electric rather than the usual
vacum pods but then had
the vacum pipe from cyl 1 piped into the brake servo vacum from cyl
4......so cyl 1 & 4 were giving
the vacum for the servo......I/we (john clegg) have ammended this back to
running just from cyl 4
and it has made no difference (conclusion being that the vacum from the
cylinders was fine whether
running from 1cylinder or 2)
I have the girling servo and wondered if (as john clegg mentioned) the air
release valve may be the cause..
I have see john's servo but it didnt help much as he has a lockheed
servo.......
what about the master cylinder?
what about the seals in the sevo?
anyone got any ideas...........?
thanks
G

[elansprint71]

One area which can cause brakes to stick on (and then maybe release over
time, or not) is an internally collapsed flexible hose. These are usually
undetectable from the outside, particularly if it is a braided hose. As your
car is a new aquisition maybe you should change these (unless you are sure
that they are reasonably new). How many wheels are affected? If more than
one, above MAY not apply, but is worth knowing about anyway.

Cheers,

Pete

-----Original Message-----
From: Gareth Flanagan [mailto:***@***.***
Sent: 10 June 2002 11:48
To: ***@***.***
Subject: [LotusElan.net] servo and brakes..............


dear elaners..............
I have a bit of a problem with my brakes and/or servo and wondered if any of
you had experienced similar.....
it goes a bit like this................
drive car......use brakes to stop/slow (brakes fine)........use brakes again
(mush stiffer this time).....
use brakes again (need two feet to stop the car)........brakes are now stuck
on.........drive on and they
release.......
this also occurs when parking up as the brakes will stick on after moving
into parking spot but after
half an hour of so the release...........
my car had had its head lights altered to electric rather than the usual
vacum pods but then had
the vacum pipe from cyl 1 piped into the brake servo vacum from cyl
4......so cyl 1 & 4 were giving
the vacum for the servo......I/we (john clegg) have ammended this back to
running just from cyl 4
and it has made no difference (conclusion being that the vacum from the
cylinders was fine whether
running from 1cylinder or 2)
I have the girling servo and wondered if (as john clegg mentioned) the air
release valve may be the cause..
I have see john's servo but it didnt help much as he has a lockheed
servo.......
what about the master cylinder?
what about the seals in the sevo?
anyone got any ideas...........?
thanks
G

[EMA7K]

Guys
just had the garage on......... (when it comes to stopping I'd rather have
the pro's do it)
the servo was losing pressure........
does this sound familliar?
cheers
G

[Elan45]

G,

Unless your talking about P Matty or a few other Lotus shops in UK or one of about a half dozen scattered around the US, I would guess your problem isnot solved. If your talking about Midas or Tuffy or Sears Auto center etc., I know your problems are just beginning. I'm not a pessimist, just a realist.

Roger



just had the garage on......... (when it comes to stopping I'd rather have
the pro's do it)
the servo was losing pressure........
does this sound familliar?
cheers
G

[john.p.clegg]

Gareth
looks like a replacement servo as the repair kits for the girling units are
thin on the ground these days,however when,if you fit a new remote lockheed
unit and the brakes stick on,i know the fix for it
p.s.
try giving classicar automotive a ring(01625 860910)they are the bizz.
john
68plus2


-----Original Message-----
From: Gareth Flanagan [mailto:***@***.***
Sent: 10 June 2002 14:27
To: '***@***.***'
Subject: RE: [LotusElan.net] servo and brakes..............


Guys
just had the garage on......... (when it comes to stopping I'd rather have
the pro's do it)
the servo was losing pressure........
does this sound familliar?
cheers
G

["Brian"]

Gareth,

I second the call about Classicar Automotive. Been around for must be almost
20yrs and I've bought stuff from them, plus sensible advice.

Fixing it myself, servo would be my first port of call. Also the master
cylinder - is it fully returning or maintaining a small amount of pressure ?
Collapsed hose is another which has already been mentioned, but I'd expect
that to be only one wheel, and you'd probably drive through that, feel the
car pulling or see smoke from the wheel

let's know how you do....

Brian

[jeff jackson]

Thats where I got my servo from. No problems at all.
My old servo sucked the brake fluid out of the master cylinder and bunt it
in no. 4 Cylinder, result : No brakes, no fluid, and loads of smoke!!
Jeff.
----- Original Message -----
From: "Brian" <***@***.***>

Sent: Monday, June 10, 2002 6:41 PM
Subject: Re: [LotusElan.net] servo and brakes..............


Gareth,

I second the call about Classicar Automotive. Been around for must be almost
20yrs and I've bought stuff from them, plus sensible advice.

Fixing it myself, servo would be my first port of call. Also the master
cylinder - is it fully returning or maintaining a small amount of pressure ?
Collapsed hose is another which has already been mentioned, but I'd expect
that to be only one wheel, and you'd probably drive through that, feel the
car pulling or see smoke from the wheel

let's know how you do....

Brian

[rodney]

All

Not that it makes any real difference, but why are the vacuum takeoffs on a
lot of cars of #4 cylinder which is at the back of the engine bay, when #1
(where mine is)is much closer to the servo and headlight tank.

Rodney Stevens
CSIRO Minerals
http://www.minerals.csiro.au

Ph. 61 2 97106701
Fax 61 2 97106789

Personal Home Page
http://mywebpage.netscape.com/rodjohnst ... mePage.htm

[kstrutt11]

Gareth,
The servo works by bolding a vacuum both sides of the diaphram and
then applying atmospheric air to one side to give you assist, if the
brakes are sticking on and the pedal efforts increasing then this
sounds like a servo problem rather than hydraulic problem. I am not
sure exactly which servo yu have but generally the air admittance to
the servo is controlled by valves linked to a piston whose movement is
dependent upon the fluid movement into the servo. There is a company
in the UK who sell parts for these older servo's and also
re-condiotion them they may be able to help, they didn't used to take
credit cards so may not be of much use if you are outside the UK.

Norton classic Servo's 01494 562235

I used them for my +2 approx 4 years ago and the service was excellent


Kevin 73 +2S130

[Lincoln62]

Had similar problem with friend's plus2. Brakes worked fine but were
sticking on.

- new seal in master cylinder - still sticking
- replaced servo (only 1 in Aus Elans) - still sticking
- rebuilt pedal box - was very rusty - better but still sticking
- swore at car - still sticking
- replaced flexible brake lines - still sticking
- ran without servo - still sticking
- swore at car again - still sticking
- pulled MC again and the piston seemed stiff - took to brake shop and
he said the seal was faulty and had swelled
- another new seal in master cylinder - fixed

Not really sure what fixed it in the end. Could have been any of the
above. I suspect a combination of sticking pedal box and dodgy seal in
MC.

I get the feeling driving this car that there is a bit of a lag with the
remote mounted servo. Maybe there is a little lag letting go as well
because of the distance between the servo and the MC?

Peter
66S2

[Foxie]

Here is one reason why brakes stick on with the Elan type master cylinder.

There are two seals in the M/C. When the brakes are operated the main piston /seal moves the fluid forward and also moves the small face seal at the front end of the internal rod/spring forward to seal the centrally drilled cylinder-to-reservoir opening. This seals the system and enables pressure to be built up.

When the brake pedal is released, the main piston moves back initially under system pressure. Only in the last few mm of travel does the thimble engage in the end of the internal rod and pulls back the front seal, thus relieving the system pressure.

I rebuilt a pedal box with the pedal free movement reduced to a minimum. The result was when the brakes were applied they locked on, and could only be freed by opening a pipe union. If the pedal was not fully returning due to a rusted shaft or weak or broken return spring it would have the same effect.

I corrected the problem by fitting shims between the M/C mounting flange and the pedal box face. I also got adjustable push-rods from Classicar but they could not be made anywhere as short as the originals.

I'm looking for good detailed section drawings of both the Girling and Lockheed servos.

Sean Murray
----- Original Message -----
From: Peter Walker
To: ***@***.***
Sent: Thursday, June 13, 2002 7:24 AM
Subject: [LotusElan.net] Sticking Brake Servo


Had similar problem with friend's plus2. Brakes worked fine but were
sticking on.

- new seal in master cylinder - still sticking
- replaced servo (only 1 in Aus Elans) - still sticking
- rebuilt pedal box - was very rusty - better but still sticking
- swore at car - still sticking
- replaced flexible brake lines - still sticking
- ran without servo - still sticking
- swore at car again - still sticking
- pulled MC again and the piston seemed stiff - took to brake shop and
he said the seal was faulty and had swelled
- another new seal in master cylinder - fixed

Not really sure what fixed it in the end. Could have been any of the
above. I suspect a combination of sticking pedal box and dodgy seal in
MC.

I get the feeling driving this car that there is a bit of a lag with the
remote mounted servo. Maybe there is a little lag letting go as well
because of the distance between the servo and the MC?

[daves56]

Peter,
In a single servo system for the +2, what is the M/C bore size? Same as
Federal version?
Dave Sutcliffe
69 +2

-----Original Message-----
From: Peter Walker [mailto:***@***.***
Sent: Thursday, June 13, 2002 1:24 AM
To: ***@***.***
Subject: [LotusElan.net] Sticking Brake Servo


Had similar problem with friend's plus2. Brakes worked fine but were
sticking on.

- new seal in master cylinder - still sticking
- replaced servo (only 1 in Aus Elans) - still sticking
- rebuilt pedal box - was very rusty - better but still sticking
- swore at car - still sticking
- replaced flexible brake lines - still sticking
- ran without servo - still sticking
- swore at car again - still sticking
- pulled MC again and the piston seemed stiff - took to brake shop and
he said the seal was faulty and had swelled
- another new seal in master cylinder - fixed

Not really sure what fixed it in the end. Could have been any of the
above. I suspect a combination of sticking pedal box and dodgy seal in
MC.

I get the feeling driving this car that there is a bit of a lag with the
remote mounted servo. Maybe there is a little lag letting go as well
because of the distance between the servo and the MC?

Peter
66S2