Bus Conversions dot Com Bulletin Board
July 29, 2014, 12:08:27 PM *
Welcome, Guest. Please login or register.

Login with username, password and session length
News: If you had an E-Mag Subscription: You will not have to go out in the rain, sleet, hail, or snow to retrieve it.
   Home   Help Forum Rules Search Calendar Login Register BCM Home Page Contact BCM  
Pages: [1]   Go Down
  Print  
Author Topic: what is normal engine cooling system pressure?  (Read 398 times)
Larry B
Full Member
***
Offline Offline

Posts: 116




Ignore
« on: January 14, 2014, 07:00:02 PM »

Happy 2014 to all-- I have been doing a shop clean up and found some items that might be of use to others. Put them in the spare tire FREE. Back to reason for this post. Every time I start my bus( 77 MCI 5B- 8/71 non turbo) it usually spits out 1/8 cup of anti-freeze. I have been ignoring this, too many other things to fix just add antifreeze now and then. I am going to change thermostats,but first decided to check glycol pressure before draining. Installed guage and start engine. At 150 F I still have no pressure. Shut engine off and added another guage to glycol overflow. Now have a totally closed system. After about 5 minutes of engine running again I have 4PSI on both guages.Shut engine off. In a few minutes the guage on the rad side of volumn tank is back to zero but I still have 4PSI on overflow side. I even opened the main glycol fill connection to make sure there was no pressure in volumn tank. This generates a few questions.
    1-Is the little brass item in the picture some sort of pressure regulating devise?
    2- If it is a pressure reg.-- is it possible it is plumbed backwards? Lets pressure out but nothing back in.
    3- How much glycol pressure should my system be operating at? I looked through my bus maint manual, I could find nothing on glycol pressure. Detroit manual anywhere from 7 to 12 PSI 
    4- When the glycol is drained I am going to add a glycol filter and charge cartridge. I have lots of hose and fitting left over from replacing fuel hoses , can I use them on supply and return to filter?
    At present I have no glycol leaks , but it appears My engine has been operating at atmophereic pressure. If I get this engine under pressure my non leaking might change. 
     5- What would be the normal level of glycol in the volumn/surge tank? 20 x6x 6 (6"deep).  During my clean up I found a sight glass that I want to install on tank.
     Thanks   Larry B
Logged

1977 MCI-5B---
8V71- 4speed man
Larry B
Full Member
***
Offline Offline

Posts: 116




Ignore
« Reply #1 on: January 14, 2014, 07:01:59 PM »

couple more pictures
Logged

1977 MCI-5B---
8V71- 4speed man
Pages: [1]   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!