Does anyone have a recommendation for a good mobile mechanic in the Pigeon Forge area? We appear to have an air leak somewhere in our gas pedal and we would like to get it fixed before heading back on the road in about three weeks.
Thanks,
Deb and Jeff
This may be of help to you;
Accelerator pedal air leak ??? (https://www.foreforums.com/index.php?topic=26936.msg218871#msg218871)
If you need the William's throttle valve this
is the cheapest with free shipping and no sales tax. One-day UPS from Rock Hill, SC.
MPParts | Williams 116697 WM90DX Fail Safe Pressure Modulating Valve | 116697 (https://mpparts.com/part/williams-116697-wm90dx-fail-safe-pressure-modulating-valve-116697)
Not mobile, but hold your nose and give Lazydays in Knoxville a call. Ask them if David is still a tech there. He worked for FT and has been working on FT's for 35 years. If he isn't there, I'd steer clear of that place. He is a great guy and prefers to work on FT's over anything else.
James Holder was at Tenn RV till Lazy days bought it. He is on the Forum and Facebook Forum. I am not sure if he is still in the rv business but he is a great guy and very helpful.
Just my two cents
Ron
Last year James Holder was over at Chilhowie RV on the Alcoa Highway, he was the service manager. Might also ask your campground folks about who they would recommend.
James is still there but they aren't set up to work with big rigs like ours.
Thanks for the information, will read through it today.
Our air pressure holds very well when parked. For example, 5 days+ after arriving in Pigeon Forge it had only dropped from 110 to around 50 PSI. The leak really manifests itself when driving up and down mountains/roiling hills (like 81 in southern VA) where you are constantly pressing down and letting up on the pedal. The white needle drops and is repressurized every 5-7 miles, the red one stays steady. On flatter terrain (i.e. I-81 between Bristol and I-40) the two needles track together and the system repressurizes only after 20-25 miles. We've been in flat terrain pretty much since October, including an unexpected six month stay in St. Augustine, so didn't really notice anything until getting into the hill country.
We had the pedal replaced 3 years ago at a small truck repair shop near Lewisburg, WVA when we developed a major leak while on I-64. At some point after that we noticed an audible puff of air every time we let up on the pedal. Didn't recall it doing that previously, but was told it was normal. Could be our imagination, but is seems like it might be getting a bit louder.
Thanks to everyone for you help
If you need the William's throttle valve this
is the cheapest with free shipping and no sales tax. One-day UPS from Rock Hill, SC
to Pigeon Forge, TN.
MPParts | Williams 116697 WM90DX Fail Safe Pressure Modulating Valve | 116697 (https://mpparts.com/part/williams-116697-wm90dx-fail-safe-pressure-modulating-valve-116697)
Jeff,
Just armchair guessing here. One thing in your post caught my eye. Your leak is being indicated by the "white needle" in your dash gauge.
On my coach, the white needle is the
rear brake tank.
On my coach, the throttle valve is supplied with air pressure from the
front brake tank (red needle).
Our coaches are enough different that the air systems may be plumbed differently. Just wondered if you have a air system diagram, and have you verified that your throttle valve is actually supplied by your
rear brake tank? If it is not, then there is a chance that your air leak is actually in some other component. For instance, the (2) rear height control valves would perhaps be more active in the mountains?
I had the exact same "white" needle behavior...turned out it was the rear drivers side "leveling valve". All good now
Rocky Valley MOBILE
(833) 486-7878
Was given as a possible source in TN from James
Thank you all for your continued responses. I'll check the Air System schematic today. Unless I am mistaking (which I generally am, multiple times per day), we don't have leveling valves as we have the torsilastic suspension. Will let you know what the schematic says.
Jeff,
I believe you are correct. I forgot about the U225 having the different suspension. So ignore any comments we made about the "leveling" valves (height control valves).
Also, due to the major difference between your U225 and my U280, I may also have been way off when talking about the air tanks and what they feed. Best bet is to study your air system diagram, and make sure you know where the air could be going when your "white" needle drops.
1992 Foretravel U225-U240 Specifications (http://web.archive.org/web/20190927023726/http://www.beamalarm.com/foretravel-links/models/1992_foretravel_u225-u240_specifications.html)
You are correct, I was able to verify that the white needle is reading the rear tank. We've been parked now for 8 days and the pressure gauges are still reading 30 lbs so that would seem to indicate the whatever it is only happens while moving.
I was finally able to dig out the schematics and the rear tank appears to have only a few connections (Brake Pedal, Rear Service Break Relay Valve, Cruise Control, cross connect to the front tank). The odd thing about the problem is that the air loss happens even when not pressing on the brake pedal for long periods of time. Rather, the leak rate
appears to be tied to the frequency of pressing down on and letting up off of the throttle pedal as described above.
However, the only apparent connection between the throttle and the rear tank is through the cruise control. Perhaps I'm reading the schematic wrong or there is something going on that I'm just not seeing. Will keep you posted on anything I find out.
I'm attaching pictures of the overall Schematic and Parts List should anyone else need the documentation.
Yes, the BENDIX cruise control is both air throttle and cruise. Look on the forward wall of your engine compartment.
Thanks Brett.
We never use the CC and always drive with the CC switch in the Off position. So that raises the following questions:
IF the leak is tied to the cycling of the throttle pedal:
- Could that pressure loss be tied to a leak in the CC?
or
- Could a leak in the Throttle Treadle Valve be responsible via a connection to the CC system? The driving force behind this question is the very audible puff of air that happens when we let up on the pedal.
Thanks again to everyone for your help.
Either end COULD be leaking.
Easy to tell-- with air pressure up, engine off, have someone work the throttle pedal while the other person listens at both the pedal and at the CC/engine room end.
Be aware that when throttle is eased/closed, air will and should exit the CC.
Thanks for the test description Brett.
We were finally able to do the pressure check. When you push on the throttle with the system pressurized and the engine off, there is a small, very brief hiss from the CC (assume this is what your last sentence is referencing). At the same time a much louder and longer puff/hiss comes from the throttle. During this process the white needle drops. while the red remains steady.
Does this seem indicate that it is the Throttle Treadle Valve is the culprit?