Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: JCinPA on May 11, 2024, 02:10:16 am

Title: 1999 U320 w/ Cummins-Air Brake Compressor cut-in and cut-out settings
Post by: JCinPA on May 11, 2024, 02:10:16 am
Hi,
  Does anyone know the correct cut-in and cut-out settings for the compressor governor for the Cummins M11?
Thank you,
John
Title: Re: 1999 U320 w/ Cummins-Air Brake Compressor cut-in and cut-out settings
Post by: Pamela & Mike on May 11, 2024, 07:24:03 am
Last Bendix school I went to between 125 to 135 was normal cut out pressure. Cut in pressure should be 20 to 25 PSI below cut out pressure. If there is more than 30 psi difference governor needs replacement.

Mike
Title: Re: 1999 U320 w/ Cummins-Air Brake Compressor cut-in and cut-out settings
Post by: Chuck & Jeannie on May 11, 2024, 08:14:35 am
Adjusting instructions for the D-2:

https://n0c357rmy1njbuit2friqwu.blob.core.windows.net/documents/BrddZ4M0I0EBhB_SD-01-503_US_005.pdf

Title: Re: 1999 U320 w/ Cummins-Air Brake Compressor cut-in and cut-out settings
Post by: dsd on May 11, 2024, 09:36:46 am
Adjusting to the upper end will improve brake operation. Probably reduces compressor life due to higher operating loads, it is worth it IMO. Not saying above 135.
Title: Re: 1999 U320 w/ Cummins-Air Brake Compressor cut-in and cut-out settings
Post by: Caflashbob on May 11, 2024, 06:25:02 pm
My memory is DOT reccomends 130 cut off for school buses.  More brakes
Title: Re: 1999 U320 w/ Cummins-Air Brake Compressor cut-in and cut-out settings
Post by: JCinPA on May 12, 2024, 12:43:05 am
Thanks folks, I really appreciate the advice, mine is running at 110 so I think some adjustments are needed. Safe travels,stay well. John
Title: Re: 1999 U320 w/ Cummins-Air Brake Compressor cut-in and cut-out settings
Post by: craneman on May 12, 2024, 10:11:49 am
I set mine at 130 psi. to make filling tires easier. Less brake pedal pressure for stopping is a side benefit.
Title: Re: 1999 U320 w/ Cummins-Air Brake Compressor cut-in and cut-out settings
Post by: oldguy on May 12, 2024, 10:13:59 am
Mine is at 130 also.
Title: Re: 1999 U320 w/ Cummins-Air Brake Compressor cut-in and cut-out settings
Post by: Doug W. on May 12, 2024, 02:28:13 pm
Less brake pedal pressure for stopping is a side benefit.

Cman said it best. 
10 psi more will not give you more braking ability if so you have a major problem. Application air pressure is pretty low with normal stops,  10 psi more will not help with an emergency stop.  Possibly more susceptible to leaks also on a old system designed for 120 max,  plus the added compressor run time.
Title: Re: 1999 U320 w/ Cummins-Air Brake Compressor cut-in and cut-out settings
Post by: Lon and Cheryl on May 12, 2024, 03:28:06 pm
I set mine to 130 for a better brake feel and more air for tire inflation.
Title: Re: 1999 U320 w/ Cummins-Air Brake Compressor cut-in and cut-out settings
Post by: Chuck & Jeannie on May 12, 2024, 05:29:37 pm
Have been running ours at 130 for 10+ years - nothing has blown up....  8)
Title: Re: 1999 U320 w/ Cummins-Air Brake Compressor cut-in and cut-out settings
Post by: dsd on May 12, 2024, 09:33:10 pm
Have been running ours at 130 for 10+ years - nothing has blown up....  8)
Glade you said it instead of me. Let us know if it bursts into flames now.