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Caliper Rebuild

PostPosted: Tue Mar 22, 2005 7:24 pm
by brassrngfm
I rebuilt all the calipers on my car during the rebuild. Contrary to the
workshop manual advice, I took them all apart and when rebuilt - replaced
the o-ring between the halves with one from Dave Bean. Quite cheap, as I
recall, and there have been no leaks. I decided to disassemble so I could
see the bores easier, since they had been off the car for years. Like you,
I had no stuck pistons, but I did replace two because of pitting. New seals
were quite easy to install with everything in half. Definitely a job you
can do youself as long as you keep everything clean
Good luck
Paul Zimmerman
65 S2

Caliper Rebuild

PostPosted: Tue Mar 22, 2005 7:45 pm
by elans4dhc
Paul,
When you rebuilt your calipers, did you re-use the original bolts that hold the caliper halves together, or did you use
new bolts? If the latter, are standard bolts OK?
Regards
Andrew King

Caliper Rebuild

PostPosted: Tue Mar 22, 2005 8:54 pm
by s2lola
Hi all,

In the past, I've used allen bolts (gasp!) to fine effect. But my
preference is proper AN hardware such that you eliminate/minimize threaded
shank in the unthreaded portion of the bolt bore. The old rumour that you
can't/shouldn't split caliper halves is a joke - use new cross seals and
everything will be just fine.

BTW, does anybody have the correct paint code for Lotus calipers (hee hee
hee!!!!).

Cheers,
Bill Tebbutt

-----Original Message-----
From: Andrew King [mailto:***@***.***
Sent: 2005/03/22 14:46
To: ***@***.***
Subject: Re: [LotusElan.net] Caliper Rebuild



Paul,
When you rebuilt your calipers, did you re-use the original bolts that hold
the caliper halves together, or did you use new bolts? If the latter, are
standard bolts OK? Regards Andrew King









To search the mailing list archives:
http://www.escribe.com/automotive/europ ... index.html

Copyright(c) LotusElan.net and the author:

Yahoo! Groups Links








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responsible for ensuring the confidentiality and integrity of the present e-mail. For this reason, the opinions expressed herein do not
necessarily reflect those of National Bank Financial and NBCN.
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Caliper Rebuild

PostPosted: Tue Mar 22, 2005 8:57 pm
by "e s"
There is no reason to split the halves.


Bores do not need to be perfect, as the seal does not ride on it.

I can't see any reason why one would not change all pistons to stainless, just asking for trouble.


two ways to remove stuck pistons:

scuba tank, 2k psi is mighty persuasive

grease gun, slow but apparently effective



----- Original Message -----
From: ***@***.***
To: ***@***.***
Subject: [LotusElan.net] Caliper Rebuild
Date: Tue, 22 Mar 2005 20:21:46 +0100



I rebuilt all the calipers on my car during the rebuild. Contrary to the
workshop manual advice, I took them all apart and when rebuilt - replaced
the o-ring between the halves with one from Dave Bean. Quite cheap, as I
recall, and there have been no leaks. I decided to disassemble so I could
see the bores easier, since they had been off the car for years. Like you,
I had no stuck pistons, but I did replace two because of pitting. New seals
were quite easy to install with everything in half. Definitely a job you
can do youself as long as you keep everything clean
Good luck
Paul Zimmerman
65 S2

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Caliper Rebuild

PostPosted: Tue Mar 22, 2005 9:18 pm
by Guest
Dear All

Never Ever used compressed gas to remove anything that is stuck it is VERY dangerous. Always use a fluid like oil or grease.

Just think of how an air rifle would work if it used oil instead of compressed air and you should get the picture.

And if you do use compressed air on your caliper dont point oi at anyone, including yourself.

Rod

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



-----Original Message-----
From: e s [mailto:***@***.***
Sent: Wednesday, 23 March 2005 7:57 AM
To: ***@***.***
Subject: Re: [LotusElan.net] Caliper Rebuild



There is no reason to split the halves.


Bores do not need to be perfect, as the seal does not ride on it.

I can't see any reason why one would not change all pistons to stainless, just asking for trouble.


two ways to remove stuck pistons:

scuba tank, 2k psi is mighty persuasive

grease gun, slow but apparently effective

Caliper Rebuild

PostPosted: Tue Mar 22, 2005 9:38 pm
by s2lola
The only reason I would split the halves is to re-plate them (yellow cad is
my preference). But Rod is right - compressed air is a no no.

There is a thread on this going back some time on this site - a great debate
about using a hand-operated grease gun (my suggestion) vs. others that are
also valid. If anyone's interested they should be able to find the
discussion. But for heaven's sake no compressed air.

Cheeres,
Bill

-----Original Message-----
From: e s [mailto:***@***.***
Sent: 2005/03/22 15:57
To: ***@***.***
Subject: Re: [LotusElan.net] Caliper Rebuild



There is no reason to split the halves.


Bores do not need to be perfect, as the seal does not ride on it.

I can't see any reason why one would not change all pistons to stainless,
just asking for trouble.


two ways to remove stuck pistons:

scuba tank, 2k psi is mighty persuasive

grease gun, slow but apparently effective



----- Original Message -----
From: ***@***.***
To: ***@***.***
Subject: [LotusElan.net] Caliper Rebuild
Date: Tue, 22 Mar 2005 20:21:46 +0100



I rebuilt all the calipers on my car during the rebuild. Contrary to
the workshop manual advice, I took them all apart and when rebuilt -
replaced the o-ring between the halves with one from Dave Bean. Quite
cheap, as I recall, and there have been no leaks. I decided to
disassemble so I could see the bores easier, since they had been off
the car for years. Like you, I had no stuck pistons, but I did replace
two because of pitting. New seals were quite easy to install with
everything in half. Definitely a job you can do youself as long as you
keep everything clean Good luck Paul Zimmerman
65 S2

--
_______________________________________________
NEW! Lycos Dating Search. The only place to search multiple dating sites at
once. http://datingsearch.lycos.com







To search the mailing list archives:
http://www.escribe.com/automotive/europ ... index.html

Copyright(c) LotusElan.net and the author:

Yahoo! Groups Links








***********************************************************************************
Financiere Banque Nationale et NBCN n'assument aucune responsabilite quant a la confidentialite et l'integrite du present courriel en raison des risques d'interception inherents a l'Internet. Pour cette raison, toute opinion exprimee au terme des presentes ne reflete pas necessairement celle de Financiere Banque Nationale et de NBCN.
***********************************************************************************
Due to the security risks involved in sending information over the Internet, National Bank Financial and NBCN can not be held
responsible for ensuring the confidentiality and integrity of the present e-mail. For this reason, the opinions expressed herein do not
necessarily reflect those of National Bank Financial and NBCN.
***********************************************************************************

Caliper Rebuild

PostPosted: Tue Mar 22, 2005 10:03 pm
by M100
On Wed, 23 Mar 2005 08:18:50 +1100, <***@***.***> wrote:

Never Ever used compressed gas to remove anything that is stuck it is VERY dangerous. Always use a fluid like oil or grease.

Just think of how an air rifle would work if it used oil instead of compressed air and you should get the picture.

And if you do use compressed air on your caliper dont point oi at anyone, including yourself.

I'd always use grease with a troublesome piston followed by a full
strip and degrease rather than ever letting compressed air near a
caliper - but in the past few days AP (suppliers of the Elise front
calipers) have published a procedure for caliper overhaul that says
use compressed air.

http://www.apracing.com/roadcar/caliper/calservice1.htm


Martin

72/45
--

Caliper Rebuild

PostPosted: Tue Mar 22, 2005 10:45 pm
by mikecauser
On Wed, 23 Mar 2005 08:18:50 +1100 <***@***.***> wrote:

Never Ever used compressed gas to remove anything that is stuck it is
VERY dangerous. Always use a fluid like oil or grease.

Well there's compressed gas, and there's compressed gas. I've
sucessfully used a bicycle pump to shift caliper pistons, with the
nozzle held to the caliper inlet by hand (small area even at 120psi
gives a low overall force). Once the piston starts to move the pressure
drops very rapidly and the piston cannot come all the way out at the
first attempt. However, no way would I use a shop compressor with its
storage tank -- even if I had one :-/


Mike
--
Mike Causer Email - mailto:***@***.***
GPG KeyID 1C2DDA07 WWW - http://www.mikecauser.com
Flood the fen again! - Wicken Fen enlargement - http://www.wicken.org.uk

Caliper Rebuild

PostPosted: Wed Mar 23, 2005 12:49 am
by lotuselan2
I second that it is a no issue to split caliper halves. New seal and you
are back in business.

Ken

'69 +2 with BDR



_____

From: Bill Tebbutt [mailto:***@***.***
Sent: Tuesday, March 22, 2005 3:54 PM
To: '***@***.***'
Subject: RE: [LotusElan.net] Caliper Rebuild
Importance: High



Hi all,

In the past, I've used allen bolts (gasp!) to fine effect. But my
preference is proper AN hardware such that you eliminate/minimize threaded
shank in the unthreaded portion of the bolt bore. The old rumour that you
can't/shouldn't split caliper halves is a joke - use new cross seals and
everything will be just fine.

BTW, does anybody have the correct paint code for Lotus calipers (hee hee
hee!!!!).

Cheers,
Bill Tebbutt

-----Original Message-----
From: Andrew King [mailto:***@***.***
Sent: 2005/03/22 14:46
To: ***@***.***
Subject: Re: [LotusElan.net] Caliper Rebuild



Paul,
When you rebuilt your calipers, did you re-use the original bolts that hold
the caliper halves together, or did you use new bolts? If the latter, are
standard bolts OK? Regards Andrew King









To search the mailing list archives:
http://www.escribe.com/automotive/europ ... index.html

Copyright(c) LotusElan.net and the author:
http://www.lotuselan.net/publish/legal_stuff.shtml
Terms of Service.

Caliper Rebuild

PostPosted: Wed Mar 23, 2005 1:14 am
by "e s"
Bunch of baloney.

Did this myself, biggest problem is that once one piston comes out it has to be held in place to get the other out. If a caliper were to come apart during this process, it would be have been very dangerous in service, as the brake pressure can get that high. Other than that there is no danger, the pistons CANNOT shoot anywhere.
----- Original Message -----
From: "Martin Evans" <***@***.***>
To: ***@***.***
Subject: Re: [LotusElan.net] Caliper Rebuild
Date: Tue, 22 Mar 2005 22:03:05 +0000


On Wed, 23 Mar 2005 08:18:50 +1100, <***@***.***> wrote:

> Never Ever used compressed gas to remove anything that is stuck
> it is VERY dangerous. Always use a fluid like oil or grease.
>
> Just think of how an air rifle would work if it used oil instead
> of compressed air and you should get the picture.
>
> And if you do use compressed air on your caliper dont point oi at
> anyone, including yourself.

I'd always use grease with a troublesome piston followed by a full
strip and degrease rather than ever letting compressed air near a
caliper - but in the past few days AP (suppliers of the Elise front
calipers) have published a procedure for caliper overhaul that says
use compressed air.

http://www.apracing.com/roadcar/caliper/calservice1.htm


Martin

72/45
--

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NEW! Lycos Dating Search. The only place to search multiple dating sites atonce.
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Caliper Rebuild

PostPosted: Wed Mar 23, 2005 1:15 am
by "e s"
Just don't see the need to.


----- Original Message -----
From: Lotus <***@***.***>
To: ***@***.***
Subject: RE: [LotusElan.net] Caliper Rebuild
Date: Tue, 22 Mar 2005 19:51:06 -0500


I second that it is a no issue to split caliper halves. New seal and you
are back in business.

Ken

'69 +2 with BDR



_____

From: Bill Tebbutt [mailto:***@***.***
Sent: Tuesday, March 22, 2005 3:54 PM
To: '***@***.***'
Subject: RE: [LotusElan.net] Caliper Rebuild
Importance: High



Hi all,

In the past, I've used allen bolts (gasp!) to fine effect. But my
preference is proper AN hardware such that you eliminate/minimize threaded
shank in the unthreaded portion of the bolt bore. The old rumour that you
can't/shouldn't split caliper halves is a joke - use new cross seals and
everything will be just fine.

BTW, does anybody have the correct paint code for Lotus calipers (hee hee
hee!!!!).

Cheers,
Bill Tebbutt

-----Original Message-----
From: Andrew King [mailto:***@***.***
Sent: 2005/03/22 14:46
To: ***@***.***
Subject: Re: [LotusElan.net] Caliper Rebuild



Paul,
When you rebuilt your calipers, did you re-use the original bolts that hold
the caliper halves together, or did you use new bolts? If the latter, are
standard bolts OK? Regards Andrew King









To search the mailing list archives:
http://www.escribe.com/automotive/europ ... index.html

Copyright(c) LotusElan.net and the author:
http://www.lotuselan.net/publish/legal_stuff.shtml

Terms of Service.





--
_______________________________________________
NEW! Lycos Dating Search. The only place to search multiple dating sites atonce.
http://datingsearch.lycos.com

Caliper Rebuild

PostPosted: Wed Mar 23, 2005 8:25 am
by steveww
The AP site uses a bar between the pistons to stop them flying away.

Hmmm.... the bicycle pump idea is a good one, I'll remember that.

High pressure gas cylinders are very dangerous things. Once I watched a
welding tank fall over, knock off its regulator on the way down then
take off across the shop finally exiting through a brick wall. A clean
pair of overalls were required afterwards ;-)

Martin Evans wrote:
On Wed, 23 Mar 2005 08:18:50 +1100, <***@***.***> wrote:


>Never Ever used compressed gas to remove anything that is stuck it is VERY dangerous. Always use a fluid like oil or grease.
>
>Just think of how an air rifle would work if it used oil instead of compressed air and you should get the picture.
>
>And if you do use compressed air on your caliper dont point oi at anyone, including yourself.


I'd always use grease with a troublesome piston followed by a full
strip and degrease rather than ever letting compressed air near a
caliper - but in the past few days AP (suppliers of the Elise front
calipers) have published a procedure for caliper overhaul that says
use compressed air.

http://www.apracing.com/roadcar/caliper/calservice1.htm


Martin

72/45

--

Regards,

Steve Waterworth
***@***.***

Einstein: "The faster you drive, the slower you age..."

Caliper Rebuild

PostPosted: Wed Mar 23, 2005 8:27 am
by M100
On Tue, 22 Mar 2005 20:15:15 -0500, "e s" <***@***.***>
wrote:

>On Tue, 22 Mar 2005 19:51:06 -0500, "Lotus" <***@***.***> wrote:

>
>I second that it is a no issue to split caliper halves. New seal and you
>are back in business.
>

Just don't see the need to.


Given that some of the calipers in use may have been around for 40
years and the sliding seals are replaced as a matter of routine every
few years, then what chance do the o rings stand when exposed to fluid
for close to half a century?

Also a few years of usage in the UK particularly over winter makes
your calipers look a mess visually if not operationally, an acid dip
and replate usually gets them back to an as new condition - not really
achievable without replacing the O rings and bolts hence I'd prefer to
change them (or get someone like classicar to do it for me)

Can anyone tell me why "DOT3" wrecked British brake seals as Girling
Crimson was rated as SAE 70 R3?

Martin

72/45
--

Caliper Rebuild

PostPosted: Wed Mar 23, 2005 12:33 pm
by Rob_LaMoreaux
I'd always use grease with a troublesome piston followed by a full
strip and degrease rather than ever letting compressed air near a
caliper - but in the past few days AP (suppliers of the Elise front
calipers) have published a procedure for caliper overhaul that says
use compressed air.

http://www.apracing.com/roadcar/caliper/calservice1.htm



I do note that AP says "a perfect seal between the air gun and fitting is
neither necessary or advisable". They are using low pressure air on the
pistons so they do not explode out and damage themselves against the
"reaction block".

Compressed air will continue to expand after the piston comes loose, where
an uncompressible liquid will stop expanding when the piston begins to move.
One of the best ways to move the piston is an hydraulic pump and hydraulic
fluid including the master cylinder of the car.

Rob LaMoreaux
Ann Arbor, MI USA
(734)-971-5583
Cell (734)-604-9280
Email: ***@***.***
Too many Hobbies.... Too Little Time
1969 Lotus Elan....It's not a restoration, it's a never-ending adventure.

Caliper Rebuild

PostPosted: Wed Mar 23, 2005 2:00 pm
by TYPE45 at aol.com
Martin,

It's not the rating that is the issue here. British brake seals are made of
pure rubber, or at least they used to be. Practically all of the rest of the
brake seals made world wide are made of Neoprene. The only brake fluid that
does not attack pure rubber is made by Castrol, be it Castrol Girling Crimson,
Castrol LMA, etc. (I'm not sure about synthetic, but why take the chance?)

I found this out the hard way in 1970 when, after rebuilding the brakes on my
TR-4, I disregarded the notification on the MC cap that said "Use Castrol
Girling Crimson Only". I thought it was nothing more than an advertisement for
Castrol, and I was wrong. It took about six months for the standard brake
fluid to turn the brand new seals into chewing gum.

Hope this answers your question.

Frank Howard
'71 S4 SE
Minnesota