Bus Conversions dot Com Bulletin Board
October 25, 2014, 07:43:38 AM *
Welcome, Guest. Please login or register.

Login with username, password and session length
News: If you had an Online Subscription: You will not incur forwarding fees when you are on the road.
   Home   Help Forum Rules Search Calendar Login Register BCM Home Page Contact BCM  
Pages: [1] 2  All   Go Down
  Print  
Author Topic: R12-DC relay valve again  (Read 5682 times)
rwc
No longer will be Now AM
Sr. Member
****
Offline Offline

Posts: 265





Ignore
« on: October 03, 2012, 10:18:33 AM »

Sorry but after the last valve turned out to be Parking brake pressure regulator replaced it and now can here leak from this valve which I think is the real R12. The air schematic for the 102D3 is not very helpful. Pictures attached.
Logged

bevans6
Hero Member
*****
Offline Offline

Posts: 4763


1980 MCI MC-5C




Ignore
« Reply #1 on: October 03, 2012, 11:42:03 AM »

I'd just replace it, they aren't very expensive.  Does it leak all the time, or just when the service brakes are applied?  Do you have spring brakes, or DD-3's?  It takes service air pressure from the dry tank and sends it to the rear brake chambers under control of the brake pedal via a small diameter control line.

Brian
Logged

1980 MCI MC-5C, 8V-71T from a M-110 self propelled howitzer
Spicer 8844 4 speed Zen meditation device
Vintage race cars -
1978 Lola T440 Formula Ford
1972 NTM MK-4 B/SR
rwc
No longer will be Now AM
Sr. Member
****
Offline Offline

Posts: 265





Ignore
« Reply #2 on: October 03, 2012, 01:36:02 PM »

I had planned on replacing this but I need to identify it first. It is made by Bendix and the numbers that I can find cast into top is T-294826-A and above that 45013 and above that 95. I went to bendix site and put in part number but nothing matched.
Logged

rwc
No longer will be Now AM
Sr. Member
****
Offline Offline

Posts: 265





Ignore
« Reply #3 on: October 03, 2012, 03:05:18 PM »

Nope it is also not an R12-DC relay valve. It is a R14 brake relay valve for the rear brakes.  Identified by Hausman bus Sales service department Dallas, Texas. My air schematic identifies it as r12. Thanks Rod
Logged

buswarrior
Hero Member
*****
Offline Offline

Posts: 3571


'75 MC8 8V71 HT740




Ignore
« Reply #4 on: October 03, 2012, 09:06:40 PM »

Go to the copy shop and get a big copy of the air schematic.

And then write on it when you change out an air component or hose.

Your goal is to work your way through and change 'em all out, then you know what is what.

And the coach will be reliable for a long time.

Those valves look horrible in the pics. Start budgeting a systematic replacement.

happy coaching!
buswarrior
Logged

Frozen North, Greater Toronto Area
rwc
No longer will be Now AM
Sr. Member
****
Offline Offline

Posts: 265





Ignore
« Reply #5 on: October 04, 2012, 06:28:01 AM »

I had an architect friend print schematic out on his plotter it is 24"X36". I will take your advice about labeling the valves That I replace. Thanks Rod
Logged

belfert
Hero Member
*****
Offline Offline

Posts: 5448




Ignore
« Reply #6 on: October 04, 2012, 08:14:30 AM »

If you have spring brakes you can actually have bad brake chambers that appear to be a leaking valve.

Most brake valves aren't all that expensive if you buy remanufactured valves.  The problem I have with remanufactured valves is they paint over the label and everything so you no longer know what the part number is if you need to replace the valve in the future.  Some valves can have many different part numbers depending on crack pressure and such.
Logged

Brian Elfert - 1995 Dina Viaggio 1000 Series 60/B500 - 75% done but usable - Minneapolis, MN
Oonrahnjay
Hero Member
*****
Offline Offline

Posts: 1512





Ignore
« Reply #7 on: October 04, 2012, 10:25:10 AM »

If you have spring brakes you can actually have bad brake chambers that appear to be a leaking valve.

Most brake valves aren't all that expensive if you buy remanufactured valves.  The problem I have with remanufactured valves is they paint over the label and everything so you no longer know what the part number is if you need to replace the valve in the future.  Some valves can have many different part numbers depending on crack pressure and such.

    Yeah, I *always* record part numbers off the box for all the brake parts I put on my bus.  I have a 'text file' in the "Brake" info folder just for this.
Logged

Bruce H; Wallace (near Wilmington) NC
1976 Daimler (British) Double-Decker Bus; 34' long
6-cyl, 4-stroke, Leyland O-680 engine

(New Email -- brucebearnc@ (theGoogle gmail place) .com)
Gary LaBombard
"Rustless Money Pit"
Hero Member
*****
Offline Offline

Posts: 944


WWW

Ignore
« Reply #8 on: October 04, 2012, 08:26:51 PM »

RWC
Here is a few photos of what I have been working on for months to replace all my old DD3 brake system and the worthless valves that worked it, well worthless now days after so much neglect as you can see.  I offer this only as something for you to consider doing one day.
Gary


Above photo is of front left wheel well before clean up and installation of new brake system.


Above photo, after clean up, refabing front wheel well and installation of new air tanks and air lines etc.


Above photo is of left drive wheel air system if you can find it.  This is the tunnel between both drive wheels.


Above photo, another view looking down air system tunnel toward the engine



Above photo is of cleaned up framing on left driver wheel side


Above photo is of new brake valves, (SR-1, R-12, R-14) Valves and new connecting brake lines all labeled corresponding to a schematic I made up of actual location of all valves and where the lines run to.


Above photo of new left drive wheel well air brake system all totally enclosed for a lifetime of protection.  Aluminum cover for enclosure is removable on both sides of bus for inspection for air leaks etc.

Only thing left now is the installation of all new brake canisters and running the only lines that will be exposed to any weather which is about 2-3 ft. in length.  Everything else is enclosed.

Logged

Gary
luvrbus
Hero Member
*****
Online Online

Posts: 12769




Ignore
« Reply #9 on: October 04, 2012, 08:52:21 PM »

Gary, what is the purpose of the SR-1 valve did you change to a dual air system ? and why a R-12 and a R-14 the R-14 should have been all you needed it is a anti compounding and quick release valve all in one,you are looking good there maybe soon huh

good luck
Logged

Life is short drink the good wine first
belfert
Hero Member
*****
Offline Offline

Posts: 5448




Ignore
« Reply #10 on: October 05, 2012, 06:22:45 AM »

Gary, that looks awesome!  I don't have any need to replumb my brakes, but the underside could use painting in spots.
Logged

Brian Elfert - 1995 Dina Viaggio 1000 Series 60/B500 - 75% done but usable - Minneapolis, MN
Gary LaBombard
"Rustless Money Pit"
Hero Member
*****
Offline Offline

Posts: 944


WWW

Ignore
« Reply #11 on: October 05, 2012, 07:03:15 AM »

Belfort, thanks for the kind words.  Sure was discouraging to look at in the beginning as you can see in my photos above.

Cliff,
To answer your question I used a (six wheel truck) schematic from Bendex to redo all my air brake system.  I asked for help from nearly every one here in Greenville to give me advice on what and how to install my brake system complete and no one would commit to help me, (I think for legal reasons) so they will not be held responsible.  I even went to a local bendex store here, I bought most valves there by the way.  The young man there had no idea what in heck I was trying to do with such an old vehicle, he wanted me to switch over to disc brakes, good grief!!  So I called bendex and they advised me to use that drawing to redo my entire system, and here I am 4 months later and many, many dollars later.  Sad

I truly cannot answer your question cliff, I only hope that I did correct and before I give out all the information of what I did for others to consider I need to have the schematic that took me weeks to remake over checked over by someone who does know what they are doing, I want to be sure that my schematic is correct and ready to go for others to receive if wanted.  Wink 

It is difficult to do a complete system like I did, with no real knowledge of what in heck you are doing and it took many weeks for me to decide what to do and learn a darn ole CAD program, (Thanks to Jon Morris for teaching me) as well to make up my own schematic using a (six wheel truck) original bendix drawing to work from.  I am waiting on a friend to look at my schematic and check what I have done before I give it out to anyone.  I made my schematic  to be near the actual location of all valves and tanks so they will be easier to locate for me and anyone owning my bus after I am gone home.

I wish I had your knowledge Cliff, maybe I made a lot more work out of what I done but what else could I do.  It is done now, any changes that really need to be made can be as I now know where everything is.  Getting to it will be a bummer but at least it will not be dirty like the original photos above.

Anyhow with this normal long explanation I hope I did do alright Cliff for a complete new spring brake system.
Gary
« Last Edit: October 05, 2012, 07:07:51 AM by Gary LaBombard » Logged

Gary
Sam 4106
Hero Member
*****
Offline Offline

Posts: 645





Ignore
« Reply #12 on: October 05, 2012, 07:44:12 AM »

Gary, do you have an on line photo album that you could post a link to? I, along with others, would enjoy looking at all the terrific work you have done on your bus. I can only imagine how much time and effort you have put into your project. I am in AWE of your workmanship. Give yourself a few pats on the back for me.

Thanks, Sam
Logged

1976 MCI-8TA with 8V92 DDEC II and Allison HT740
Gary LaBombard
"Rustless Money Pit"
Hero Member
*****
Offline Offline

Posts: 944


WWW

Ignore
« Reply #13 on: October 05, 2012, 07:58:29 AM »

Sam,
Thanks for comment. I have been working on my bus 10 years now, even the termites in my set up blocks holding up the bus are anxious for this project to get over with. 

I do not see the same screen you see on photobucket.com but I will give you the link I have and it should bring you to all my albums to view on the right hand side menu of the screen you open.
  
http://s629.photobucket.com/albums/uu19/busconverter101/

If this link does not open for you then go to (photobucket.com) and put in (busconverter101) in the photobucket search window.  
Gary

« Last Edit: October 05, 2012, 08:07:40 AM by Gary LaBombard » Logged

Gary
Oonrahnjay
Hero Member
*****
Offline Offline

Posts: 1512





Ignore
« Reply #14 on: October 05, 2012, 11:38:29 AM »

  (snip)  I used a (six wheel truck) schematic from Bendex to redo all my air brake system.  


      Gary, I had a very similar experience as yours regarding getting "professional" assistance -- except one retired Greyhound mechanic (actually foreman of GH's Charlotte bus garage his last 10 years there).  Unfortunately, he seemed to have forgotten something along the way ... he designed a system with wet, primary, secondary tanks "in series" with no protection between them; any leak anywhere would have taken resulted in the entire system leaking down.  His schematic for quick releases etc. was also "unconventional".

      I did exactly what you did with the Bendix standard schematic based on the SR-7 relay valve*, except I simplified the schematic to eliminate the additional axle (have a two-axle bus).  I asked the Bendix Tech Support people for their help and they made some minor adjustments (location of the one-way valves etc.).  I bought parts around this and installed them and ran the lines in accordance with their instructions.  I also signed up for the Bendix brake school (may be the best money I spent since I bought the bus) and went through my setup with the instructor -- we discussed some options in the system and he also approved my schematic.

    Here is my simplified Bendix diagram:

http://s45.photobucket.com/albums/f60/oonrahnjay/Bus/?action=view&current=SR71Page.jpg   I found it easier to use two single one-way valves at the tank outputs to the S-port on the SR-7 valve; this means that the air pipe layout is a little different but the functionality is the same. 

    Of course, on the bus, I had to add a wet tank with the primary and secondary tanks fed from that; also, the accessory tank (with one way and "protection" valves) is taken off the wet tank, too. 

(*  The SR-7 valve is a relay and quick release valve for the rear service brakes; it requires a separate R-14 valve for anti-compounding for the parking/spring brakes).

      That's a beautiful installation job, Gary.  I'm going to go back and look to see if I can enclose my components like that.

BruceH   NC   USA

   
Logged

Bruce H; Wallace (near Wilmington) NC
1976 Daimler (British) Double-Decker Bus; 34' long
6-cyl, 4-stroke, Leyland O-680 engine

(New Email -- brucebearnc@ (theGoogle gmail place) .com)
Pages: [1] 2  All   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines Valid XHTML 1.0! Valid CSS!