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Topic: Leaking 6-pack pressure switch (Read 762 times) previous topic - next topic

Leaking 6-pack pressure switch

1998 U-320 36' M11 Celect Plus

I was finally able to get under the coach today and check for air leaks on the front six pack.

One of the 10 PSI Hobbs pressure switches has a constant leak at the end of the unit where the rubber cap is located.  The photo below is from Chuck & Jeannie's six pack thread from a couple years ago.

Does this mean that the unit has failed and needs to be replaced?

Thank you.

Chris

Re: Leaking 6-pack pressure switch

Reply #1 –
Quote from: Numbers –
Does this mean that the unit has failed and needs to be replaced?

Chris,

The short answer "Yes" 
The pressure switches can be gotten at some parts stores just take the old one in to see if they can match it up.

Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Leaking 6-pack pressure switch

Reply #2 –
Mike,

Thank you for the reply.

Chris

Re: Leaking 6-pack pressure switch

Reply #4 –
Excuse my ignorance, but what is the purpose of this pressure switch?
Forest & Cindy Olivier
1987 log cabin
2011 Roadtrek C210P
no longer 1999 36' U320 build #5522
2013 Rzr 570 & 2018 Ranger XP1000
2006 Lexus GX470
2011 Tahoe LT 4x4
Previous 1998 45' 2 slide Newell, 1993 39' Newell

Re: Leaking 6-pack pressure switch

Reply #5 –
Quote from: folivier –
Excuse my ignorance, but what is the purpose of this pressure switch?

https://www.hwhcorp.com/ml20635.pdf    (Page 19, System Pressure Switches)

"The front air pressure switches on all 600 and 680 Series Leveling Systems are used during any lower functions, manual operation, automatic operation or use of the "DUMP" button. When the pressure switch for a front bag turns on, it sends a ground signal to the control box. This will inhibit the opposite side front air bags from lowering.
EXAMPLE: While pushing the right side lower button, the right front air pressure switch sees low air pressure. The front lower button is then pushed. The right front lower solenoid valve will turn on and open, but the left front lower solenoid valve will not turn on. The left front bag will not lower. This is done to prevent the front of the vehicle from twisting. If one side of the front of the vehicle is as low as it can go, lowering the other side will twist the vehicle."
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Leaking 6-pack pressure switch

Reply #6 –
Thanks Chuck.
Forest & Cindy Olivier
1987 log cabin
2011 Roadtrek C210P
no longer 1999 36' U320 build #5522
2013 Rzr 570 & 2018 Ranger XP1000
2006 Lexus GX470
2011 Tahoe LT 4x4
Previous 1998 45' 2 slide Newell, 1993 39' Newell

Re: Leaking 6-pack pressure switch

Reply #7 –
Received the new pressure switches today (replacement plus one spare), got it installed (not easy), and am doing a leak test right now.

Removing the old pressure switch was not easy.  The threaded end of the switch had fused to the 45 degree brass fitting.  I didn't want to remove all the other air line components on the six pack (7 more chances for something else to go wrong).  I ended up cutting the pressure switch off between the brass fitting and the base of the switch using a small hack saw.  Once the switch was off it was easy to remove the old 45 degree brass fitting.

New fitting and new pressure with were installed using yellow teflon tape (gas rated tape) and the joints passed the soap bubble test.

Chris

Re: Leaking 6-pack pressure switch

Reply #8 –

Chris,

I'm not criticizing or second guessing your work, but most of our more experienced "tech" members recommend using a thread sealing paste on air system fitting, rather than tape.  Doing so reduces the chance of introducing a stray bit of tape into the air lines, where it might end up fouling one of the valves.  Just something to consider next time.

I've had good luck with Permatex - found in most auto parts stores.  6 ml tube will last a long time.

Amazon.com: Permatex 59214 High Temperature Thread Sealant, 6 ml Tube:...

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Leaking 6-pack pressure switch

Reply #9 –
How many of these low pressure switches are used through out the entire system?
As old as my coach is I'm sure all this stuff needs to be replaced before it eventually fails.
1995 U320C SE 40'
Jeep 4x4 Commander - Limited - Hemi
"The Pack"  Yogi and Diesel our Airedales -  Charlie our Boxer/Akita mix. Gone but NEVER forgotten Jake our yellow Lab.
NRA Law Enforcement Firearms instructor - Handgun/shotgun
Regional Firearms instructor for national Armored Transp. Co.

Re: Leaking 6-pack pressure switch

Reply #10 –
I would not proactively replace them.  If you have symptoms OR if you do a "soap bubble" test on the fronts 6 pack, replace the "bubblers".
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Leaking 6-pack pressure switch

Reply #11 –
Quote from: Lon and Cheryl –
How many of these low pressure switches are used through out the entire system?
2 - on the front 6-pack manifold.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"
 

Re: Leaking 6-pack pressure switch

Reply #12 –
Two low pressure switches on the front, and the one on the rear six-pack (attached to the bottom of the manifold) is a 'whole system' pressure switch with a different range than the ones on the front manifold.
Woody & Sandy Lloyd
1993 Grand Villa
Unihome U280
Cummins / Allison
Build # 4379