I'm restoring a Bendix Hydrovac brake booster & there is some light
rust damage inside the cylinder. Unfortunately it seems to be *just*
deep enough that boring out the cylinder enough to get rid of it is
going to lead to an excessively sloppy cylinder fit & probably leakage
past the seal.

What I'm thinking is to braze the inside pf the cylinder & then clean
it up with a boring bar & polishing on the lathe.

Anyone see a problem with this?

Thanks,

H.

"Howard Eisenhauer" wrote in message
...
I'm restoring a Bendix Hydrovac brake booster & there is some light
rust damage inside the cylinder. Unfortunately it seems to be *just*
deep enough that boring out the cylinder enough to get rid of it is
going to lead to an excessively sloppy cylinder fit & probably leakage
past the seal.

What I'm thinking is to braze the inside pf the cylinder & then clean
it up with a boring bar & polishing on the lathe.

Anyone see a problem with this?

Thanks,

H.

Sleeve it. It's much easier.

There used to be someone here who ran a specialty service business, sleeving
brake cylinders. Maybe he's still around.

--
Ed Huntress

On 04/19/2011 06:20 PM, Howard Eisenhauer wrote:
I'm restoring a Bendix Hydrovac brake booster& there is some light
rust damage inside the cylinder. Unfortunately it seems to be *just*
deep enough that boring out the cylinder enough to get rid of it is
going to lead to an excessively sloppy cylinder fit& probably leakage
past the seal.

What I'm thinking is to braze the inside pf the cylinder& then clean
it up with a boring bar& polishing on the lathe.

Anyone see a problem with this?

Thanks,

H.
Is there enough wall thickness to bore it out for a sleeve? any little
dimple in the repaired section will be a leak...not to say it can't be
done that way, just seems an extra path to failure.

bill

On Tue, 19 Apr 2011 19:06:01 -0700, Bill Martin
wrote:

On 04/19/2011 06:20 PM, Howard Eisenhauer wrote:
I'm restoring a Bendix Hydrovac brake booster& there is some light
rust damage inside the cylinder. Unfortunately it seems to be *just*
deep enough that boring out the cylinder enough to get rid of it is
going to lead to an excessively sloppy cylinder fit& probably leakage
past the seal.

What I'm thinking is to braze the inside pf the cylinder& then clean
it up with a boring bar& polishing on the lathe.

Anyone see a problem with this?

Sleeving appears to be the way it's done.


Is there enough wall thickness to bore it out for a sleeve? any little
dimple in the repaired section will be a leak...not to say it can't be
done that way, just seems an extra path to failure.

http://www.resleeve.com/sleeving.htm is one of 1,130,000 hits on
http://www.google.com/search?q=repair+master+cylinder

--
Live in the sunshine, swim the sea, drink the wild air...
-- Ralph Waldo Emerson

On Apr 19, 7:20*pm, Howard Eisenhauer
wrote:
I'm restoring a Bendix Hydrovac brake booster & there is some light
rust damage inside the cylinder. *Unfortunately it seems to be *just*
deep enough that boring out the cylinder enough to get rid of it is
going to lead to an excessively sloppy cylinder fit & probably leakage
past the seal.

What I'm thinking is to braze the inside pf the cylinder & then clean
it up with a boring bar & polishing on the lathe.

Anyone see a problem with this?

Thanks,

H.

Use a brass or bronze sleeve. Common restoration process for old
cars. Or find a replacement, if it's a common part.

Stan

On Apr 19, 9:20*pm, Howard Eisenhauer
wrote:

What I'm thinking is to braze the inside pf the cylinder & then clean
it up with a boring bar & polishing on the lathe.

Anyone see a problem with this?

Thanks,

H.

My brazing would take a lot of cleaning up.

If you can get a bearing ball that is big enough, you might try ball
sizing to get a smooth polished id on a sleeve.

Dan

wrote in message
...
On Apr 19, 9:20 pm, Howard Eisenhauer
wrote:

What I'm thinking is to braze the inside pf the cylinder & then clean
it up with a boring bar & polishing on the lathe.

Anyone see a problem with this?

Thanks,

H.

My brazing would take a lot of cleaning up.

If you can get a bearing ball that is big enough, you might try ball
sizing to get a smooth polished id on a sleeve.

Dan

Ordinary brake-cylinder hones (which are cheap) will do it, too. I'm not
sure you want a polished bore. It would depend on the piston material.

--
Ed Huntress

On Apr 20, 2:41*pm, "Ed Huntress" wrote:

If you can get a bearing ball *that is big enough, you might try ball
sizing to get a smooth polished id on a *sleeve.

* * * * * * * * * * * * * * * * * * * * * * * * * * * * Dan

Ordinary brake-cylinder hones (which are cheap) will do it, too. I'm not
sure you want a polished bore. It would depend on the piston material.

--
Ed Huntress

Probably a better choice for just one repair. I had thought once
about starting a business of restoring brake cylinders using stainless
tubing and using ball sizing to quickly get the id to size and also to
change the fit from a sliding fit to a press fit.

Dan

wrote in message
...
On Apr 20, 2:41 pm, "Ed Huntress" wrote:

If you can get a bearing ball that is big enough, you might try ball
sizing to get a smooth polished id on a sleeve.

Dan

Ordinary brake-cylinder hones (which are cheap) will do it, too. I'm not
sure you want a polished bore. It would depend on the piston material.

--
Ed Huntress

Probably a better choice for just one repair. I had thought once
about starting a business of restoring brake cylinders using stainless
tubing and using ball sizing to quickly get the id to size and also to
change the fit from a sliding fit to a press fit.

Dan

That's an interesting thought, but I'm not up on the practicalities of
piston-and-bore mechanics. It appears to me that every general type of
application, from IC engines to hydraulic cylinders, has its own dynamics. I
was covering honing in a big way around 10 years ago, when Sunnen
precipitated a big change in the field by using solid, diamond-impregnated
hones to cut away larger volumes of metal and to correct straightness,
roundness, and dimensions at the same time. It's quite a feat and it
introduces some tricky issues of piston-fit, because of the way that diamond
hones tear the metal surface.

Stainless as a bearing surface is another tricky issue. You get great
corrosion resistance with the higher grades in the 300 Series, but they make
terrible bearings, with a strong tendency to gall. It looks like brass and
bronze are the most practical materials for that job.

--
Ed Huntress

Ed Huntress wrote:
wrote in message
...
On Apr 20, 2:41 pm, "Ed Huntress" wrote:


If you can get a bearing ball that is big enough, you might try ball
sizing to get a smooth polished id on a sleeve.

Dan

Ordinary brake-cylinder hones (which are cheap) will do it, too. I'm not
sure you want a polished bore. It would depend on the piston material.

--
Ed Huntress



Probably a better choice for just one repair. I had thought once
about starting a business of restoring brake cylinders using stainless
tubing and using ball sizing to quickly get the id to size and also to
change the fit from a sliding fit to a press fit.

Dan


That's an interesting thought, but I'm not up on the practicalities of
piston-and-bore mechanics. It appears to me that every general type of
application, from IC engines to hydraulic cylinders, has its own dynamics. I
was covering honing in a big way around 10 years ago, when Sunnen
precipitated a big change in the field by using solid, diamond-impregnated
hones to cut away larger volumes of metal and to correct straightness,
roundness, and dimensions at the same time. It's quite a feat and it
introduces some tricky issues of piston-fit, because of the way that diamond
hones tear the metal surface.

Stainless as a bearing surface is another tricky issue. You get great
corrosion resistance with the higher grades in the 300 Series, but they make
terrible bearings, with a strong tendency to gall. It looks like brass and
bronze are the most practical materials for that job.


Interesting you mention that as a mate that works at Ricardo mentioned
when we were down the pub recently about honing technologies and how the
current processes can improve the roundness of the bores from around 10
microns as bored to 5 microns after honing. Then there was mention of
fast helical honing?, maybe I misheard, and laser honing which is not in
production use as far as he knows yet but is potentially up and coming.

"David Billington" wrote in message
...
Ed Huntress wrote:
wrote in message
...
On Apr 20, 2:41 pm, "Ed Huntress" wrote:


If you can get a bearing ball that is big enough, you might try ball
sizing to get a smooth polished id on a sleeve.
Dan

Ordinary brake-cylinder hones (which are cheap) will do it, too. I'm not
sure you want a polished bore. It would depend on the piston material.

--
Ed Huntress



Probably a better choice for just one repair. I had thought once
about starting a business of restoring brake cylinders using stainless
tubing and using ball sizing to quickly get the id to size and also to
change the fit from a sliding fit to a press fit.

Dan


That's an interesting thought, but I'm not up on the practicalities of
piston-and-bore mechanics. It appears to me that every general type of
application, from IC engines to hydraulic cylinders, has its own
dynamics. I was covering honing in a big way around 10 years ago, when
Sunnen precipitated a big change in the field by using solid,
diamond-impregnated hones to cut away larger volumes of metal and to
correct straightness, roundness, and dimensions at the same time. It's
quite a feat and it introduces some tricky issues of piston-fit, because
of the way that diamond hones tear the metal surface.

Stainless as a bearing surface is another tricky issue. You get great
corrosion resistance with the higher grades in the 300 Series, but they
make terrible bearings, with a strong tendency to gall. It looks like
brass and bronze are the most practical materials for that job.


Interesting you mention that as a mate that works at Ricardo mentioned
when we were down the pub recently about honing technologies and how the
current processes can improve the roundness of the bores from around 10
microns as bored to 5 microns after honing. Then there was mention of fast
helical honing?, maybe I misheard, and laser honing which is not in
production use as far as he knows yet but is potentially up and coming.

I don't know about laser honing. I'm a few years out of touch.

Yes, the newer honing technology doesn't allow the hone to follow the
existing walls of the hole. With diamond abrasive and a hard, unyielding
hone body, it makes its own hole shape. And it can cut quite a bit of
material. In smaller holes, they can do a lot better than 5 microns
(0.0002"). One micron is more like it.

As for helical honing, Sunnen makes production hones that are helical in
shape, and they're fast. They clear swarf like a twist drill. That may be
what he was talking about.

--
Ed Huntress

On Apr 20, 3:03*pm, "Ed Huntress" wrote:


Stainless as a bearing surface is another tricky issue. You get great
corrosion resistance with the higher grades in the 300 Series, but they make
terrible bearings, with a strong tendency to gall. It looks like brass and
bronze are the most practical materials for that job.

--
Ed Huntress

I was assuming, perhaps wrongly, that this was a bore for brakes and
the material touching the stainless would be the rubber cups, not
another metal. Or if there was metal to metal contact, there would be
almost no pressure.

Dan

wrote in message
...
On Apr 20, 3:03 pm, "Ed Huntress" wrote:


Stainless as a bearing surface is another tricky issue. You get great
corrosion resistance with the higher grades in the 300 Series, but they
make
terrible bearings, with a strong tendency to gall. It looks like brass and
bronze are the most practical materials for that job.

--
Ed Huntress

I was assuming, perhaps wrongly, that this was a bore for brakes and
the material touching the stainless would be the rubber cups, not
another metal.

Frankly, I no longer remember what it was for. g

Or if there was metal to metal contact, there would be
almost no pressure.

Dan

Stainless works fine as a bearing surface against many materials. Austenitic
(300 Series) stainless is not good against steel. I'd have to dig up some
old books to see how it does against other metals.

Hardened stainless -- 400 Series or precipitation hardening -- is another
matter. It has little tendency to gall and it runs well against other hard
steels.

--
Ed Huntress

On 4/20/2011 8:24 AM, wrote:
On Apr 19, 7:20 pm, Howard
wrote:
I'm restoring a Bendix Hydrovac brake booster& there is some light
rust damage inside the cylinder. Unfortunately it seems to be *just*
deep enough that boring out the cylinder enough to get rid of it is
going to lead to an excessively sloppy cylinder fit& probably leakage
past the seal.

What I'm thinking is to braze the inside pf the cylinder& then clean
it up with a boring bar& polishing on the lathe.

Anyone see a problem with this?

Thanks,

H.

Use a brass or bronze sleeve. Common restoration process for old
cars. Or find a replacement, if it's a common part.

Stan

just send it to White Post Restorations - they do this for a living

--
www.wbnoble.com

On Wed, 20 Apr 2011 15:03:25 -0400, "Ed Huntress"
wrote:


wrote in message
...
On Apr 20, 2:41 pm, "Ed Huntress" wrote:

If you can get a bearing ball that is big enough, you might try ball
sizing to get a smooth polished id on a sleeve.

Dan

Ordinary brake-cylinder hones (which are cheap) will do it, too. I'm not
sure you want a polished bore. It would depend on the piston material.

--
Ed Huntress

Probably a better choice for just one repair. I had thought once
about starting a business of restoring brake cylinders using stainless
tubing and using ball sizing to quickly get the id to size and also to
change the fit from a sliding fit to a press fit.

Dan

That's an interesting thought, but I'm not up on the practicalities of
piston-and-bore mechanics. It appears to me that every general type of
application, from IC engines to hydraulic cylinders, has its own dynamics. I
was covering honing in a big way around 10 years ago, when Sunnen
precipitated a big change in the field by using solid, diamond-impregnated
hones to cut away larger volumes of metal and to correct straightness,
roundness, and dimensions at the same time. It's quite a feat and it
introduces some tricky issues of piston-fit, because of the way that diamond
hones tear the metal surface.

Stainless as a bearing surface is another tricky issue. You get great
corrosion resistance with the higher grades in the 300 Series, but they make
terrible bearings, with a strong tendency to gall. It looks like brass and
bronze are the most practical materials for that job


We used to make SS stell pumps and used Waukesha 88 as a rotor this
was fit in a honed hole with a few tenths clearence and worked
perfect.
This matertal can only be purchase from the Waukesha Foundry if I
remeber correctly.

db

On Thu, 21 Apr 2011 15:30:09 -0700, Dave B wrote:

On Wed, 20 Apr 2011 15:03:25 -0400, "Ed Huntress"
wrote:


wrote in message
...
On Apr 20, 2:41 pm, "Ed Huntress" wrote:

If you can get a bearing ball that is big enough, you might try ball
sizing to get a smooth polished id on a sleeve.

Dan

Ordinary brake-cylinder hones (which are cheap) will do it, too. I'm not
sure you want a polished bore. It would depend on the piston material.

--
Ed Huntress

Probably a better choice for just one repair. I had thought once
about starting a business of restoring brake cylinders using stainless
tubing and using ball sizing to quickly get the id to size and also to
change the fit from a sliding fit to a press fit.

Dan

That's an interesting thought, but I'm not up on the practicalities of
piston-and-bore mechanics. It appears to me that every general type of
application, from IC engines to hydraulic cylinders, has its own dynamics. I
was covering honing in a big way around 10 years ago, when Sunnen
precipitated a big change in the field by using solid, diamond-impregnated
hones to cut away larger volumes of metal and to correct straightness,
roundness, and dimensions at the same time. It's quite a feat and it
introduces some tricky issues of piston-fit, because of the way that diamond
hones tear the metal surface.

Stainless as a bearing surface is another tricky issue. You get great
corrosion resistance with the higher grades in the 300 Series, but they make
terrible bearings, with a strong tendency to gall. It looks like brass and
bronze are the most practical materials for that job


We used to make SS stell pumps and used Waukesha 88 as a rotor this
was fit in a honed hole with a few tenths clearence and worked
perfect.
This matertal can only be purchase from the Waukesha Foundry if I
remeber correctly.

db

lol, I should use spell check

db

"Dave B" wrote in message
...
On Wed, 20 Apr 2011 15:03:25 -0400, "Ed Huntress"
wrote:


wrote in message
...
On Apr 20, 2:41 pm, "Ed Huntress" wrote:

If you can get a bearing ball that is big enough, you might try ball
sizing to get a smooth polished id on a sleeve.

Dan

Ordinary brake-cylinder hones (which are cheap) will do it, too. I'm not
sure you want a polished bore. It would depend on the piston material.

--
Ed Huntress

Probably a better choice for just one repair. I had thought once
about starting a business of restoring brake cylinders using stainless
tubing and using ball sizing to quickly get the id to size and also to
change the fit from a sliding fit to a press fit.

Dan

That's an interesting thought, but I'm not up on the practicalities of
piston-and-bore mechanics. It appears to me that every general type of
application, from IC engines to hydraulic cylinders, has its own dynamics.
I
was covering honing in a big way around 10 years ago, when Sunnen
precipitated a big change in the field by using solid, diamond-impregnated
hones to cut away larger volumes of metal and to correct straightness,
roundness, and dimensions at the same time. It's quite a feat and it
introduces some tricky issues of piston-fit, because of the way that
diamond
hones tear the metal surface.

Stainless as a bearing surface is another tricky issue. You get great
corrosion resistance with the higher grades in the 300 Series, but they
make
terrible bearings, with a strong tendency to gall. It looks like brass and
bronze are the most practical materials for that job


We used to make SS stell pumps and used Waukesha 88 as a rotor this
was fit in a honed hole with a few tenths clearence and worked
perfect.
This matertal can only be purchase from the Waukesha Foundry if I
remeber correctly.

db

Aha. A "nickel-based alloy with anti-galling properties." That would explain
why it makes a decent bearing surface.

Regular austenitic stainless galls easily.

--
Ed Huntress

"Dave B" wrote in message
...
On Wed, 20 Apr 2011 15:03:25 -0400, "Ed Huntress"
wrote:


wrote in message
...
On Apr 20, 2:41 pm, "Ed Huntress" wrote:

If you can get a bearing ball that is big enough, you might try ball
sizing to get a smooth polished id on a sleeve.

Dan

Ordinary brake-cylinder hones (which are cheap) will do it, too. I'm not
sure you want a polished bore. It would depend on the piston material.

--
Ed Huntress

Probably a better choice for just one repair. I had thought once
about starting a business of restoring brake cylinders using stainless
tubing and using ball sizing to quickly get the id to size and also to
change the fit from a sliding fit to a press fit.

Dan

That's an interesting thought, but I'm not up on the practicalities of
piston-and-bore mechanics. It appears to me that every general type of
application, from IC engines to hydraulic cylinders, has its own dynamics.
I
was covering honing in a big way around 10 years ago, when Sunnen
precipitated a big change in the field by using solid, diamond-impregnated
hones to cut away larger volumes of metal and to correct straightness,
roundness, and dimensions at the same time. It's quite a feat and it
introduces some tricky issues of piston-fit, because of the way that
diamond
hones tear the metal surface.

Stainless as a bearing surface is another tricky issue. You get great
corrosion resistance with the higher grades in the 300 Series, but they
make
terrible bearings, with a strong tendency to gall. It looks like brass and
bronze are the most practical materials for that job


We used to make SS stell pumps and used Waukesha 88 as a rotor this
was fit in a honed hole with a few tenths clearence and worked
perfect.
This matertal can only be purchase from the Waukesha Foundry if I
remeber correctly.

db

It's an interesting material. Apparently the bismuth prevents galling. You
may find this short piece from _Design News_ interesting:

http://www.designnews.com/article/11..._machinery.php

--
Ed Huntress

On Thu, 21 Apr 2011 19:03:20 -0400, "Ed Huntress"
wrote:


"Dave B" wrote in message
.. .
On Wed, 20 Apr 2011 15:03:25 -0400, "Ed Huntress"
wrote:


wrote in message
...
On Apr 20, 2:41 pm, "Ed Huntress" wrote:

If you can get a bearing ball that is big enough, you might try ball
sizing to get a smooth polished id on a sleeve.

Dan

Ordinary brake-cylinder hones (which are cheap) will do it, too. I'm not
sure you want a polished bore. It would depend on the piston material.

--
Ed Huntress

Probably a better choice for just one repair. I had thought once
about starting a business of restoring brake cylinders using stainless
tubing and using ball sizing to quickly get the id to size and also to
change the fit from a sliding fit to a press fit.

Dan

That's an interesting thought, but I'm not up on the practicalities of
piston-and-bore mechanics. It appears to me that every general type of
application, from IC engines to hydraulic cylinders, has its own dynamics.
I
was covering honing in a big way around 10 years ago, when Sunnen
precipitated a big change in the field by using solid, diamond-impregnated
hones to cut away larger volumes of metal and to correct straightness,
roundness, and dimensions at the same time. It's quite a feat and it
introduces some tricky issues of piston-fit, because of the way that
diamond
hones tear the metal surface.

Stainless as a bearing surface is another tricky issue. You get great
corrosion resistance with the higher grades in the 300 Series, but they
make
terrible bearings, with a strong tendency to gall. It looks like brass and
bronze are the most practical materials for that job


We used to make SS stell pumps and used Waukesha 88 as a rotor this
was fit in a honed hole with a few tenths clearence and worked
perfect.
This matertal can only be purchase from the Waukesha Foundry if I
remeber correctly.

db

It's an interesting material. Apparently the bismuth prevents galling. You
may find this short piece from _Design News_ interesting:

http://www.designnews.com/article/11..._machinery.php


Thats what we were using it for 25 years ago.
We manufactured vertical form-fill and seal machines and used this
material because it was easy to remove after use for sanitation.
Of course it was the only material that would work with that tight of
clearance.

Regards
db