Vacuum diaphragm

This forum is dedicated to the Live Steam Hobbyist Community.

Moderators: cbrew, Harold_V

Post Reply
egingerfl
Posts: 3
Joined: Fri Aug 08, 2014 4:48 pm

Vacuum diaphragm

Post by egingerfl »

Does anyone know where I can buy a vacuum diaphragm for vacuum brakes?
Bill C
Posts: 258
Joined: Fri Aug 08, 2008 9:14 pm
Location: Pensacola, FL

Re: Vacuum diaphragm

Post by Bill C »

Mountain Car Company uses them in the brake kits they sell, so you might try them. These are basically just little vacuum devices like are used for vacuum advance on automobile distributors. If know what you are looking for, the friendly parts counter folks at the local NAPA or O'Reilly's might help you find what you need.

I hope that helps,

Bill C.
User avatar
Pipescs
Posts: 2194
Joined: Wed Feb 03, 2010 10:16 pm
Location: Lester Alabama

Re: Vacuum diaphragm

Post by Pipescs »

Joseph Nelson has a part number in his book (So you want to build a live steam locomotive) for a Delco Remy part number F-1302 which is for a 3 inch diameter vacuum advance for a Ford Distributer. It is in chapter 14 on a simple train brake system.

Talking with a fellow modeler up north, I understand this number may have changed but you may still be able to cross reference at an automotive parts store.
Charlie Pipes
Mid-South Live Steamers


Current Projects:

Scratch Built 3 3/4 scale 0-4-4 Forney
Little Engines American
20 Ton Shay (Castings and Plans Purchased for future)
User avatar
Trainman4602
Posts: 3482
Joined: Sat Oct 16, 2004 9:26 pm
Location: New Jersey

Re: Vacuum diaphragm

Post by Trainman4602 »

Hi All

I have around 20 of the vacuum chambers that Charlie mentioned. I would like to sell them here is a picture .
They are the exact part pictures described in Joe's book. There were to be used on 6 wheeled passenger cars but I developed the air brake setup and never used them. They are 3 inches in diameter. PM me if interested.
Attachments
Picture 016.jpg
Picture 017.jpg
ALLWAYS OPERATING MY TRAIN IN A SAFE MANNER USING AUTOMATIC AIR BRAKES
User avatar
Fred_V
Posts: 4370
Joined: Sun Jan 12, 2003 3:26 pm

Re: Vacuum diaphragm

Post by Fred_V »

I use the heat/air conditioner damper diaphragms from a junk yard. They are typically larger than distributor advances.
Fred V
Pensacola, Fl.
User avatar
Steampipe
Posts: 189
Joined: Sun Dec 07, 2003 8:49 pm
Location: 40 Mile West of Philadelpha

Re: Vacuum diaphragm

Post by Steampipe »

Go to Reilly Auto parts and buy online - or Ebay.
User avatar
Dan Willey
Posts: 485
Joined: Wed Feb 19, 2003 10:44 pm
Location: North Carolina, USA

Re: Vacuum diaphragm

Post by Dan Willey »

I recently rebuilt a couple Mountain Car Company trucks that have brakes. I researched and it seems that MCC used a "choke pull-off" from a 1980's Ford. The vacuum pull-off is modified a bit... mounting bracket cut/ground off, and adjusting screw replaced with a screw-eye. I found them all over eBay and bought one as a spare.

I have attached a couple photos of the rebuilt and painted MCC truck and brake rigging.

Here is an example on eBay ($14.95 free shipping). The prices are all over the place so search carefully.
http://www.ebay.com/itm/Standard-Motor- ... fc&vxp=mtr

Dan
Attachments
IMG_5078m.JPG
IMG_5080m.JPG
IMG_5082m.JPG
1/8 scale: Mercer Locomotive K4, Saturated Steam E6
Full scale: Woodings CBL speeder/motorcar NARCOA
egingerfl
Posts: 3
Joined: Fri Aug 08, 2014 4:48 pm

Re: Vacuum diaphragm

Post by egingerfl »

Hi Dan, thanks, you gave me the information I needed.
User avatar
Greg_Lewis
Posts: 3014
Joined: Wed Jan 15, 2003 2:44 pm
Location: Fresno, CA

Re: Vacuum diaphragm

Post by Greg_Lewis »

Some years ago the late, great, Charlie Dockstader sent me drawings for making your own out of PVC pipe and old inner tube rubber. If anyone would like a copy of the drawings, send me a P.M. and I'll email them to you.
Greg Lewis, Prop.
Eyeball Engineering — Home of the dull toolbit.
Our motto: "That looks about right."
Celebrating 35 years of turning perfectly good metal into bits of useless scrap.
User avatar
NP317
Posts: 4557
Joined: Tue Jun 24, 2014 2:57 pm
Location: Northern Oregon, USA

Re: Vacuum diaphragm

Post by NP317 »

I use the Mountain Car Co. vacuum brakes shown above, and have learned one issue that should be attended to before putting them in service:
The plastic body material is relatively soft and the threads for the screw eye-bolt in the vacuum cylinder will wear and begin leaking air, decreasing the available vacuum. I have "R&Rd" them by sealing the eye bolts in place with silicon rubber sealant. Problem solved.
~RN
User avatar
shayloco
Posts: 264
Joined: Fri Mar 28, 2003 11:00 am
Location: Rhode Island

Re: Vacuum diaphragm

Post by shayloco »

Greg_Lewis wrote:Some years ago the late, great, Charlie Dockstader sent me drawings for making your own out of PVC pipe and old inner tube rubber. If anyone would like a copy of the drawings, send me a P.M. and I'll email them to you.
Thanks for the drawings, Greg.

Just wanted to mention that there are not only the brake vacuum cylinder but a brake valve and steam ejector plans too. A little difficult to read but the info is there. One doesn't have to use pvc, the brake cylinders could be made from brass using the same dimensions.

Good stuff if you like to build your own equipment.

-Larry
User avatar
Fred_V
Posts: 4370
Joined: Sun Jan 12, 2003 3:26 pm

Re: Vacuum diaphragm

Post by Fred_V »

I enjoyed seeing them too. I would like to comment on the ejector. If the exhaust side were made longer a lock nut could be added to aid adjustment.
Attachments
Screen Shot 2015-02-02 at 5.52.01 PM.png
Fred V
Pensacola, Fl.
Post Reply