Skip to main content ↑ ↓
Topic: Air System Leveling Valves (Read 1179 times) previous topic - next topic

Air System Leveling Valves

Has anyone replaced or overhauled air system valves, i.e., the older three-lever leveling system in older FTs? (Mine is an '89 U300 GV.)

My valves are leaking, causing strange airbag behavior, unleveling, etc.

Does FT carry hardware replacements for these, or is this a third-party supplier?

Any information will be very much appreciated.
1989 Foretravel U300 Grand Villa
Build #3410

Re: Air System Leveling Valves

Reply #1 –
Are you talking about the RIDE HEIGHT VALVES?
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: Air System Leveling Valves

Reply #2 –
If I remember right the cables move the ride height valves so you should be able to replace them. Take one official and take it to a truck parts place to see if they can match it up.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Air System Leveling Valves

Reply #3 –
Quote from: red tractor –
If I remember right the cables move the ride height valves so you should be able to replace them. Take one official and take it to a truck parts place to see if they can match it up.

Correct, but assume it is only the ride height valves that could leak as the mechanical linkage can't.
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: Air System Leveling Valves

Reply #4 –
Yes the cables move a plate that the ride height valve is bolted to.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Air System Leveling Valves

Reply #5 –
Randall,
I replaced all three on my coach.  OEM valves had a plastic body with brass inserts at the air connections.  The plastic cracked around the inserts and leaked.  I replaced them with all metal valves. 
Meritor WABCO S4640024430:
http://www.anythingtruck.com/product/650-S4640024430.html

I should add I also replaced some of the rubber linkage parts.  I had one crack in half.  I don't have any records for where I purchased those; probably locally at a truck shop.
John Fitzgerald
1991 U300 (SAI) Side Aisle Island Bed 40'
Detroit 6V92 with Allison Retarder
Meridian (Boise), Idaho

Re: Air System Leveling Valves

Reply #6 –
Here's are a few catalog pages from a supplier with some part numbers for linkages and other brands of valves.
John Fitzgerald
1991 U300 (SAI) Side Aisle Island Bed 40'
Detroit 6V92 with Allison Retarder
Meridian (Boise), Idaho

Re: Air System Leveling Valves

Reply #7 –
Brett,

Yes. Sorry. Brain fog.
1989 Foretravel U300 Grand Villa
Build #3410

Re: Air System Leveling Valves

Reply #8 –
Chiming in because I am actually doing the  work on Randall's coach. Didn't want it torn down in the shop area, with no leads on parts.
You really can't see much of it, till we tear it out.
Even as a tech, I never had any experience with this style system. It sure doesn't look like HWH.
It might be my bad, but sure looks like 3 way manual air valves that dump and raise the coach. They are defiantly leaking through, and very temperamental.

Thanks for any input
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: Air System Leveling Valves

Reply #9 –
That was not a HWH system. I think that it was designed by Foretravel.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Air System Leveling Valves

Reply #10 –
Quote from: red tractor –
That was not a HWH system. I think that it was designed by Foretravel.
Pretty sure it wasn't. Thanks
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: Air System Leveling Valves

Reply #11 –
Don't have a lot of experience with that style leveler, but believe that it mechanically changed the ride height valve orientation to "fool it" into raising or lowering that position.

Others who have more first hand experience with that vintage system will hopefully chime in.
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: Air System Leveling Valves

Reply #12 –
Brett is exactly right.  It's a CM Fore designed system and I think it is quite clever.  It's very simple and doesn't add any extra air connections.  There is no circuit boards, sensors, or 6 packs so little can go wrong.  The control levers (next to the driver's seat) push and pull a cable that rotates a pivot plate at each right height valve location.  The ride height valve is mounted on the pivot plate with it's lever axis positioned over the axis of rotation for the pivot plate.  Move the control lever and the ride height valve is fooled into adding or subtracting air.  The control levers are a position control: you move them to a position (to get leveled) and you leave them in that position.  When the control levers are in the their middle detent position, then it's at travel height.  There's a micro switch on each lever such that the dash "air level" light goes on whenever any lever is out of the middle detent position.

I recommend taking apart the pivot plate, cleaning everything and reassembling with some grease.  There's a spring in the pivot that keeps the slop in the system to one side so there is no dead zone.  The worse thing that can happen is if the push-pull cable becomes frozen due to corrosion, just like in the steering system on a boat with an outboard motor and steering wheel.  But with it under the floor there's not much water getting to it; mine is still original.  Hope this helps.
John Fitzgerald
1991 U300 (SAI) Side Aisle Island Bed 40'
Detroit 6V92 with Allison Retarder
Meridian (Boise), Idaho

Re: Air System Leveling Valves

Reply #13 –
Quote from: JohnFitz –
Brett is exactly right.  It's a CM Fore designed system and I think it is quite clever.  It's very simple and doesn't add any extra air connections.  There is no circuit boards, sensors, or 6 packs so little can go wrong.  The control levers (next to the driver's seat) push and pull a cable that rotates a pivot plate at each right height valve location.  The ride height valve is mounted on the pivot plate with it's lever axis positioned over the axis of rotation for the pivot plate.  Move the control lever and the ride height valve is fooled into adding or subtracting air.  The control levers are a position control: you move them to a position (to get leveled) and you leave them in that position.  When the control levers are in the their middle detent position, then it's at travel height.  There's a micro switch on each lever such that the dash "air level" light goes on whenever any lever is out of the middle detent position.

I recommend taking apart the pivot plate, cleaning everything and reassembling with some grease.  There's a spring in the pivot that keeps the slop in the system to one side so there is no dead zone.  The worse thing that can happen is if the push-pull cable becomes frozen due to corrosion, just like in the steering system on a boat with an outboard motor and steering wheel.  But with it under the floor there's not much water getting to it; mine is still original.  Hope this helps.

Thanks, great info. It functions different then I thought. Great idea for a system.
Randall had mentioned, that as the coach was airing up, the right front began to raise only. I told him to be careful, as it could pop the windshield. Whats strange, is if the system uses only one rife height valve in the front, I wonder why it would raise the right front 1st, before going to level?

While working on it here, the coach was raised all the way up, and left over night with the levers all the way back. In the morning, the front was all the way down, but the rear was still up.

Just want to collect all the info I can, before we tear into it.

Thanks for your input
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: Air System Leveling Valves

Reply #14 –
Quote from: wolfe10 –
Don't have a lot of experience with that style leveler, but believe that it mechanically changed the ride height valve orientation to "fool it" into raising or lowering that position.

Others who have more first hand experience with that vintage system will hopefully chime in.

You mean we stumped the professor?  :(
Thanks Brett
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: Air System Leveling Valves

Reply #15 –
Thanks very much to all, for input and info.
1989 Foretravel U300 Grand Villa
Build #3410

Re: Air System Leveling Valves

Reply #16 –
Quote from: JohnFitz –
Brett is exactly right.  It's a CM Fore designed system and I think it is quite clever.  It's very simple and doesn't add any extra air connections.  There is no circuit boards, sensors, or 6 packs so little can go wrong.  The control levers (next to the driver's seat) push and pull a cable that rotates a pivot plate at each right height valve location.  The ride height valve is mounted on the pivot plate with it's lever axis positioned over the axis of rotation for the pivot plate.  Move the control lever and the ride height valve is fooled into adding or subtracting air.  The control levers are a position control: you move them to a position (to get leveled) and you leave them in that position.  When the control levers are in the their middle detent position, then it's at travel height.  There's a micro switch on each lever such that the dash "air level" light goes on whenever any lever is out of the middle detent position.

I recommend taking apart the pivot plate, cleaning everything and reassembling with some grease.  There's a spring in the pivot that keeps the slop in the system to one side so there is no dead zone.  The worse thing that can happen is if the push-pull cable becomes frozen due to corrosion, just like in the steering system on a boat with an outboard motor and steering wheel.  But with it under the floor there's not much water getting to it; mine is still original.  Hope this helps.

Thanks John for your input.I am posting this response for the history, for anyone else that comes up with this issue.

You were 100% correct (never doubted you). We pulled the swivel part apart, cleaned and re lubed all three mounts.They were all rusty.

We also cleaned the control levers inside where they pivot.

Randal's ride height was also 3/4" too high in the front. Which probably messed with the position of the ride height valve.

Ray Fore was a genius, super simple, fool proof system.

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: Air System Leveling Valves

Reply #17 –
I had it on my 280 and my opinion we would all be better off issue wise if we still had it on late model coaches now. I know I miss it and my hwh problems haven't even started yet.. The are coming no doubt.
Dub McBride 1996 270