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Topic: Accelerator pedal air leak ??? (Read 1128 times) previous topic - next topic

Accelerator pedal air leak ???

I have noticed an air leak coming from around the accelerator pedal. It developed sometime on our last trip and is only noticeable when the engine and generator are off. Being a relatively new FT owner, I was unaware the accelerator  pedal was air operated. Is this a common problem?
I found only one post on this topic and it mentions replacing a base valve?
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: Accelerator pedal air leak ???

Reply #1 –
Could it be coming from your treadle valve? It is right next to the throttle.
1999 40 ft. U-320 wtfe build 5563 Chuck & Lynda's "Rollin' Inn"  2030 watts solar
prev. mh's 71 GMC 5 yrs. 73 Pace Setter 1 yr. 78 Vogue 5 yrs 81 FTX 40ft all electric 18 yrs. 1996 Monaco Signature 3 yrs.
2014 Grand Cherokee Overland
Dream as if you will live forever. Live as if you will die today.  James Dean

Re: Accelerator pedal air leak ???

Reply #2 –
You may have a Williams air throtte.  Mechanical engine. 
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Accelerator pedal air leak ???

Reply #3 –
Yes, very likely a connection at the treadle valve.
Peter & Beth Martin
No Forrest? What have you done?
MC# 15890 until Dec 2016; FMCA #F329677
Cincinnati, OH

Re: Accelerator pedal air leak ???

Reply #4 –
Bendix air throttle on older units not sure when the transition to wire feed King control took place.
Doug W.
96 36' U270 CSGI #4946
04 Toyota Tacoma 4x4
PNW

Re: Accelerator pedal air leak ???

Reply #5 –
Quote from: Doug W. li date=1449536284
Bendix air throttle on older units not sure when the transition to wire feed King control took place.

It could be..... There is a cylinder (bendix) I believe, under the bed mounted next to the Racor fuel filter. I think there is a cable running from it to the curb side of the 8.3.

Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: Accelerator pedal air leak ???

Reply #6 –
Here are some photos of the Bendix unit on our coach, located on the forward wall in the engine compartment.  It combines the throttle and cruise control functions.  Also a (corrected) diagram of the air lines in this system.  Your may be similar.
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: Accelerator pedal air leak ???

Reply #7 –
Here is a "training manual" for the Bendix unit.  It contains much valuable info, although the system is somewhat modified in the Foretravel dual mode application (which is why I "corrected" the diagram linked above).

http://www.wanderlodgeownersgroup.com/downloads/BendixCruiseCtlManual_Parts.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: Accelerator pedal air leak ???

Reply #8 –
The term "treadle valve" can be associated with either the air brake control or the air throttle control.  My owner's manual has some paperwork referring to the Williams WM453109 Treadle Valve.  Looks like the "gas pedal" in our coach.  The air valve sub-assembly (under the pedal) is a WM90DX.  If yours needs repair parts, or replacement, both should be readily available.

WM90DX by WILLIAMS CONTROLS - Fail-Safe Pressure Modulating Valve
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: Accelerator pedal air leak ???

Reply #9 –
Thanks for all the info, I'll dig into it this weekend. Hopefully it's just a seal or O ring needed.
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: Accelerator pedal air leak ???

Reply #10 –
Based on the drawing (S-090) page 6
The air is coming from item 17 (dust boot) won't get the chance to disassemble anything until this weekend.
With any luck there will be an O ring that can be replaced rather than the complete valve assembly.
Doesn't seem to affect anything other than the loss of air in the tank (white needle on pressure gauge) too quickly.
Justin & Cathy Byrd
1995 U280 "Old Faithful"
36' Build #4673
C8.3 Cummins
Allison MD3060R 6 speed - retarder
Powertech 10KW  4cyl Kubota

Re: Accelerator pedal air leak ???

Reply #11 –
Quote from: FourTravelers –
Based on the drawing (S-090) page 6
The air is coming from item 17 (dust boot) won't get the chance to disassemble anything until this weekend.
With any luck there will be an O ring that can be replaced rather than the complete valve assembly.
Doesn't seem to affect anything other than the loss of air in the tank (white needle on pressure gauge) too quickly.

I have had the pedal assembly make funny noises under my foot during operation after the assembly started leaking pressure
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4
 

Re: Accelerator pedal air leak ???

Reply #12 –
Williams Controls repair kit #117103
The selected media item is not currently available.Bill&Doris 97 U270 36'
University of Parris Island Class of 66
Semper Fi  Build# 5174 MC#17094