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Topic: 6 pack rebuild (Read 1977 times) previous topic - next topic

6 pack rebuild

I think it's easier in the long run to just pull the 6 pack unit, and do it on the bench. I know there has been a lot of discussion on this in the past.

I have been fighting a L/F a major air leak since last winter when I replaced a bad travel solenoid. I did that one while laying on my back in the Parker desert.........Way out where we had just spent the last couple of nights 'Howeling at the Moon" with our neighbor at home, and good friend Kelly Hughes

Anyway,while the engine was out this summer, I rebuilt 4 of the front valve's, and installed another new complete HWH travel solenoid to match the other one.

I used the untested ones which didn't work..... (They are NOT Tom Mc Clouds)....His work awesome

These are the one's that DID NOT work:
Inventories in Stock by Oemsurplus911.com

Once I got the coach going with the new engine, the leak was worse, I believe because of the untested ones mentioned above.So  I ordered the one's from Tom, and installed those. They look and smell like the HWH ones, but I still had an issues.

Being frustrated, I bought a couple of manual shut off valves from the hardware store to narrow down the issue.Make a short story long, I narrowed it down to the left solenoids.So I decided to just yank the manifold off, and set it up to bench test it with air.

So what did I find you asked. I guess I dropped the 'O'ring in the plunger, so it was leaking from there. Funny thing is, I soaped the heck out of it several times, it didn't show. So another good reason to pull the manifold.

Going to do the rear 6 pack this way.I rigged up a gauge and shut off valve, so I can bench test them afterwards. I also marked everything with some masking tape to make it easier. I'll remove it when done
Chris
Chris and Tammy White  CDA Idaho
Previous owners 1997 U295 36' 3126 Cat 300 HP Build # 4998
Former Foretravel tech & RVIA certified tech
Former owner Custom Satellite home/RV satellites 
Former owner Vans LTD  van conversions
Unemployed, panhandler, drag racer NHRA #6348

Re: 6 pack rebuild

Reply #1
You might check the O-rings on the check valves and the retaining plugs while you are at it.  They were in good shape on my front 6-pack, but I installed new ones anyway.  Peace of mind thing...  O-ring sizes listed in post linked below:

Working On My Six Pack
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: 6 pack rebuild

Reply #2
My low pressure sensor doesn't work on my rear 6pack. It will never stop "venting" air, even when none is left in the bags and it's sitting on the stops. Anybody ever mess with the pressure switch?
1998 U270 34'

Re: 6 pack rebuild

Reply #3
My low pressure sensor doesn't work on my rear 6pack. It will never stop "venting" air, even when none is left in the bags and it's sitting on the stops. Anybody ever mess with the pressure switch?
I don't understand your question.  The pressure switch on the rear 6-pack does not "vent air".  It is a simple pressure sensor - enclosed electrical contacts that are either open or closed, depending on what pressure it sees.  See a better explanation below:

HWH Pressure Switch Arrangements

Parts diagram with HWH part number for 85 PSI pressure switch:

http://www.hwhcorp.com/mr053300.pdf
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: 6 pack rebuild

Reply #4
You might check the O-rings on the check valves and the retaining plugs while you are at it.  They were in good shape on my front 6-pack, but I installed new ones anyway.  Peace of mind thing...  O-ring sizes listed in post linked below:

Working On My Six Pack
Good info, thanks. I did take them apart, cleaned & checked them. Also replaced both pressure switches.
Chris and Tammy White  CDA Idaho
Previous owners 1997 U295 36' 3126 Cat 300 HP Build # 4998
Former Foretravel tech & RVIA certified tech
Former owner Custom Satellite home/RV satellites 
Former owner Vans LTD  van conversions
Unemployed, panhandler, drag racer NHRA #6348

Re: 6 pack rebuild

Reply #5
I don't understand your question.  The pressure switch on the rear 6-pack does not "vent air".  It is a simple pressure sensor - enclosed electrical contacts that are either open or closed, depending on what pressure it sees.  See a better explanation below:

HWH Pressure Switch Arrangements

Parts diagram with HWH part number for 85 PSI pressure switch:

http://www.hwhcorp.com/mr053300.pdf


Thanks for the links and info. I'll look at the pressure switch and maybe replace it. Mine is stuck and not working.

Edit: I think it may be this drawing or one like this...20 psi pressure switch. It's in the manifold assembly to maintain at least 20psi in the air bags: https://www.hwhcorp.com/mr053325.pdf
1998 U270 34'

Re: 6 pack rebuild

Reply #6
Edit: I think it may be this drawing or one like this...20 psi pressure switch.
That drawing is the front HWH 6-pack manifold.  HWH uses two 20 PSI switches on that manifold.  Foretravel uses two 10 PSI pressure switches.

Normally Closed, originally made by Honeywell, part # 76578-10 NC.  Their function is described in the beamalarm.com link I posted above.

Shop around for the best price.

Stewart Warner-Stewart Warner Hobbs Pressure Switch 10 PSI Normally Closed 2...
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: 6 pack rebuild

Reply #7
So safe to order 4 switches at 10 psi? for both packs? going to have all the new parts in before tear down..Thanks

Re: 6 pack rebuild

Reply #8
That drawing is the front HWH 6-pack manifold.  HWH uses two 20 PSI switches on that manifold.  Foretravel uses two 10 PSI pressure switches.

Normally Closed, originally made by Honeywell, part # 76578-10 NC.  Their function is described in the beamalarm.com link I posted above.

Shop around for the best price.

Stewart Warner-Stewart Warner Hobbs Pressure Switch 10 PSI Normally Closed 2...

THANK YOU!  I love this forum.
1998 U270 34'

Re: 6 pack rebuild

Reply #9
So safe to order 4 switches at 10 psi? for both packs? going to have all the new parts in before tear down..Thanks

Front use's 2, rear uses one. They are different.
Read here:

HWH Pressure Switch Arrangements
Chris and Tammy White  CDA Idaho
Previous owners 1997 U295 36' 3126 Cat 300 HP Build # 4998
Former Foretravel tech & RVIA certified tech
Former owner Custom Satellite home/RV satellites 
Former owner Vans LTD  van conversions
Unemployed, panhandler, drag racer NHRA #6348

Re: 6 pack rebuild

Reply #10
i have had those pressure switches leak.  when they do, i just take them out and plug the hole until i find one.  i have had to replace the rear one and one of the front ones.  each coach manufacturer seems to put a slightly different pressure reading ones on.  give or take 10 psi or so. 

they are in my mind nice to have but not totally necessary.  when they are disconnected they are in a state that still allows the system to work.  what they do is tell you if you have enough air in the system to float the bags, or that you are completely low on air.  if you have them out or disconnected, you just have to be aware of your air pressure situation. 

tom
Tom & Darlene McCloud
2002 Newell Coach #608
Wittmann, AZ

Re: 6 pack rebuild

Reply #11
Reiterating what Chris said:

FRONT MANIFOLD:  TWO 10 PSI SWITCHES
REAR MANIFOLD:    ONE 85 PSI SWITCH

The front pressure switches are easy to find. See the link posted above (Reply #6).  The 85 PSI switch is another matter entirely...

It is a funny coincidence that Tom just posted (above) because I was just reading one of his posts on another forum from 7 years ago!  Seems this pesky 85 PSI switch has been a thorn in the side of RV owners for many years.  Here is what my Google search turned up.

First, the HWH part number is RAP90570, and (if available) it is probably pretty pricey from them, but I didn't actually call to get a quote.

Searching online for the HWH part number, I found these pertinent discussions:

Travel Light Issue

what is this thing on the rear 6 pack? - Luxury Coach Lifestyles  (Tom's old post)

Where can I get Nason pressure switches (for HWH) at a discount price? -...

Those three threads led me to these sources for a substitute (but not exact duplicate) 85 PSI switch:

Presur Swtch,Stndrd,51 to 90 psi,SPST-NC HONEYWELL 76064-B00000600-01 | eBay

Honeywell Presur Swtch, Stndrd, 51 to 90 psi, SPST-NC 76064-B00000600-01 |...

SM-2B-85R Monaco Parking Brake Switch

OR, you can go to Partdeal.com, and order the same-as-OEM NASON switch, and wait a few weeks for them to build it:

Nason Switches
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: 6 pack rebuild

Reply #12
Reiterating what Chris said:

FRONT MANIFOLD:  TWO 10 PSI SWITCHES
REAR MANIFOLD:    ONE 85 PSI SWITCH

The front pressure switches are easy to find. See the link posted above (Reply #6).  The 85 PSI switch is another matter entirely...

It is a funny coincidence that Tom just posted (above) because I was just reading one of his posts on another forum from 7 years ago!  Seems this pesky 85 PSI switch has been a thorn in the side of RV owners for many years.  Here is what my Google search turned up.

First, the HWH part number is RAP90570, and (if available) it is probably pretty pricey from them, but I didn't actually call to get a quote.

Searching online for the HWH part number, I found these pertinent discussions:

Travel Light Issue

what is this thing on the rear 6 pack? - Luxury Coach Lifestyles  (Tom's old post)

Where can I get Nason pressure switches (for HWH) at a discount price? -...

Those three threads led me to these sources for a substitute (but not exact duplicate) 85 PSI switch:

Honeywell Presur Swtch, Stndrd, 51 to 90 psi, SPST-NC 76064-B00000600-01 |...

SM-2B-85R Monaco Parking Brake Switch

OR, you can go to Partdeal.com, and order the same-as-OEM NASON switch, and wait a few weeks for them to build it:

Nason Switches

Thanks Chuck for expanding my comment. I had just waken up, planned to come back and post links to the place to purchase them. But you did it for me :D

I went back and looked at your rebuild. Very nice professional job. I loved the way you stamped the hose numbers on the block.Those push on fittings work nice. I use them on my race car for air activated stuff.I probably should have changed mine, but just going to re-install it today. I need to move the coach.

Thanks for all your input. I post for the purpose of archiving stuff, for future help for other's. Others like yourself, have helped me immensely with their real world experience.

Cheers Chris
Chris and Tammy White  CDA Idaho
Previous owners 1997 U295 36' 3126 Cat 300 HP Build # 4998
Former Foretravel tech & RVIA certified tech
Former owner Custom Satellite home/RV satellites 
Former owner Vans LTD  van conversions
Unemployed, panhandler, drag racer NHRA #6348

Re: 6 pack rebuild

Reply #13
Thanks for all your input. I post for the purpose of archiving stuff, for future help for other's.
Yer Welcome.  I actually post mostly for my OWN benefit, to help ME remember exactly what I've done (and when) to our coach.  Senility Sucks!  8)
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: 6 pack rebuild

Reply #14
Woo Woo.....Success!


Did not drop even 1/8" at every corner in the last 24 hrs. Auto level off
Chris and Tammy White  CDA Idaho
Previous owners 1997 U295 36' 3126 Cat 300 HP Build # 4998
Former Foretravel tech & RVIA certified tech
Former owner Custom Satellite home/RV satellites 
Former owner Vans LTD  van conversions
Unemployed, panhandler, drag racer NHRA #6348

Re: 6 pack rebuild

Reply #15
36 hours, not 1/6th inch drop at any corner. So far 12 psi out of both tanks. All the work of fixing the multi leaks at the tanks paid off.
I never really got a good test, because the front 6 pack was giving me grief.

*** Auto level off***
Chris and Tammy White  CDA Idaho
Previous owners 1997 U295 36' 3126 Cat 300 HP Build # 4998
Former Foretravel tech & RVIA certified tech
Former owner Custom Satellite home/RV satellites 
Former owner Vans LTD  van conversions
Unemployed, panhandler, drag racer NHRA #6348

Re: 6 pack rebuild

Reply #16
Good news.  Your work paid off.
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: 6 pack rebuild

Reply #17
Thanks Brett. I think I'll leave the rear 6 pack alone. If it ain't broke don't fix it. I actually replaced 2 kits back there last year.The raise was bad, but it lowered when it sat. I would roll out of bed in the morning.kind of tricked me to find the issue.
I did order a new rear pressure switch, I am going to do that. It looks crusty.
Chris
Chris and Tammy White  CDA Idaho
Previous owners 1997 U295 36' 3126 Cat 300 HP Build # 4998
Former Foretravel tech & RVIA certified tech
Former owner Custom Satellite home/RV satellites 
Former owner Vans LTD  van conversions
Unemployed, panhandler, drag racer NHRA #6348

Re: 6 pack rebuild

Reply #18
DONE....
Calculates out to 1 PSI per hour loss in each tank. Not even going to try and find that, even if I could.
On to the last minor project for now
Chris
Chris and Tammy White  CDA Idaho
Previous owners 1997 U295 36' 3126 Cat 300 HP Build # 4998
Former Foretravel tech & RVIA certified tech
Former owner Custom Satellite home/RV satellites 
Former owner Vans LTD  van conversions
Unemployed, panhandler, drag racer NHRA #6348

Re: 6 pack rebuild

Reply #19
Thought I'd tack a few photos on the end of this thread, since they pertain to the same topic...

In Reply #11 I listed 3 possible sources for substitute 85 PSI pressure switches that could be used on the rear HWH 6-pack manifold.  I decided to order one of them, to put away in my spare parts drawer for a rainy day.  I picked the 3rd of the three options listed, just because it looked kinda interesting.  Switch arrived today, and it appears to me to be a high quality component.  It is heavy - about the weight of a good 1" hex socket.  Chrome plated or stainless steel - not sure which -  to resist corrosion.  Includes a heavy duty rubber boot to cover the two wiring contacts after the wires are attached.  The boot should help the switch live a long life in the dirty, greasy and sometimes wet environment under the coach.

The switch is adjusted by inserting a Allen wrench into a socket screw between the wiring contacts.  It is supposed to come set for 85 PSI.  I will probably do a bench test to confirm the setting, and will report back later with the results.

SM-2B-85R Monaco Parking Brake Switch

After I got the switch in hand, I did a Google search for the ID info etched on the side, and got a lot of hits, most of them at cheaper prices than the link I posted.  Looks like most of them are made in China.  I don't know if they are all selling the same switch, or if some are rip-off copies.  Caveat emptor.

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: 6 pack rebuild

Reply #20
Posting for those in the future

Honeywell Presur Swtch, Stndrd, 51 to 90 psi, SPST-NC 76064-B00000600-01 |...


Came pre set at 60 psi dead nuts like it say's,  I adjusted it to 85 psi...You need a brass adapter to install it, 1/8" to 1/4"pipe.

If you have no way to adjust it on the bench, turn the allen in 1/2 turn. This will put you in the ball park. Easy to readjust once on the coach.

Chris and Tammy White  CDA Idaho
Previous owners 1997 U295 36' 3126 Cat 300 HP Build # 4998
Former Foretravel tech & RVIA certified tech
Former owner Custom Satellite home/RV satellites 
Former owner Vans LTD  van conversions
Unemployed, panhandler, drag racer NHRA #6348