I have an air issue with my 1987 Grand Villa ORED (Cat 3208 Turbo, 250 HP, 76K miles). After running in cruise control, if I have to brake out of it to slow down, the air system depletes quite a way down and the accelerator is inoperable for a few seconds until the air recovers some. If it had a cable system, it acts as if the cable had stretched or broke. The air system will recover, but then fluctuate significantly 30 to 40 pounds back and forth for some time. The pump recovers it but then it quickly loses that 30-40 lbs. air again. This can go on for some time and for miles, 10, 15 or 20 until the system achieves a decent level of equilibrium. It is specific to coming off of using the cruise control. This has happened several times now. I found some leaks elsewhere in the system over the winter and corrected them, but they were not at the cruise system. This just happened again over this weekend.
There is another thread on this forum that refers to the Bendix cruise / throttle system. I found a very comparable thread on the Wanderlodge forum with a full manual. I'm thinking of rebuilding the CC-5 valve, and also have a suspicion that the RV-3 valve may be a contributor, if not the actual culprit (since this happens upon brake release of the system and has such a hard time recovering. I will also be checking the brake light switch). I really would like the opinions of this esteemed group before I go too much farther. Looking forward to your responses!
Gerry
I would think it is the rv3 valve
Forget the Bendix CC, don't use it, it's as bad as the 1960's ford CC that would run away while you were driving and wouldn't disengage.
Assuming your Bendix throttle/cruise system is the same as the one on our coach, the diagram below should illustrate it pretty well. You will see that I have corrected the diagram found in the Bendix manual, since our system is slightly different. I do not have a RV-3 valve on my system. I do have a RV-1, which is simply a pressure regulator. I do not think this has anything to do with your problem.
When you talk about the valves you suspect, you may be referring to the TR-3 Inversion Valve. I think this is indeed a likely suspect, since it is used to exhaust the air pressure in the CC-5 when you apply the brake to release the cruise control. If this valve is hanging up and not moving freely, it could cause the symptoms you describe.
I would also look at the DC-4 Shuttle Valve, which is one of the items I added to my "corrected" diagram. When you release the cruise control by applying your brake, pressure is exhausted in the line from the TR-3 to the DC-4. When that happens, the shuttle inside the DC-4 should move, which will allow the Throttle Valve (line #11) to assume control of the CC-5. If the DC-4 is hanging up, it could bleed off pressure from Line #11 and make your throttle sluggish or completely inoperable.
I believe either the TR-3 or the DC-4 will be the source of your troubles. Remove them, take them apart, and clean them up. If they are not corroded or damaged inside, they can be lubed, reassembled and reused. If too bad inside, replace them.
If you feel like rebuilding the CC-5, that certainly wouldn't hurt anything. It might make your throttle more responsive, which is a good thing.
Bendix Manual: http://www.wanderlodgeownersgroup.com/downloads/BendixCruiseCtlManual_Parts.pdf
Simple, don't turn the CC on, leave the switch on the side of the turn signal in the off position.
Or, the OP could repair or replace the malfunctioning parts, and once again have a perfectly functioning cruise control.
Of course, the choice is completely up to him.
Still not the answer to problems with that Bendix system.
I found that to stop all the issues I had with the one on the 240 we bought (it would not let engine go into idle mode with removing foot off throttle and was a very dangerous situation for our 3000 mile trip home with it) I had to dismantle the CC-5 and all the valves to clean and service them. The CC-5 was the real culprit I believe and it was bone dry inside cylinder causing the piston to hang up. The potentiometer was tested and found to be ok but once all parts were looked at etc the system worked fine as supposed to.
It is such a small job to do them all that to not too is silly. No science project at all.
JohnH
Great info Chuck! My issue has been similar as when CC is on it pulses. It's been that way since we hit a tire chick on the road and it knocked out the speedo sensor at the transmission. That part was repaired but the cruise had acted up ever since. So since I can find a mechanic that will work on the Bendix (they all suggest replacing with the "King Air" I think it's called) and repiar I have felt is over my ability level we don't use it. With this diagram I might give it a go..
I'm looking forward to hearing what the OP finds with his issue
Jeff,
You have discovered the biggest downside to this Bendix system: nobody wants (or knows how) to work on them. There may be some techs out there somewhere who still have the knowledge and skills to repair/tune these systems, but they are few and far between. SO, we are left to our own devices.
I linked to the Bendix repair manual in my post above. To my knowledge, this is the best source of information available. This system was also used on BlueBirds and some other older coaches, so you will occasionally find helpful reference to it on other forums, such as this one:
Wanderlodge Owners Group - Powered by vBulletin (http://www.wanderlodgeownersgroup.com/forums/)
When you get there, put "Bendix cruise control" in the search box on the home page - you will find a load of posts and info!
Trouble shooting: Look on Page 22 of the Bendix manual. It talks about "Surging", which may be the problem you are experiencing. Since you had the speed sensor worked on, I would start checking things there. A intermittent signal from the sensor can cause surging. John Haygarth in his post above mentioned the "potentiometer". This part is essential to proper speed control. He may have some advice on how to verify proper operation of this component. I, fortunately, have not had any problems of this type (knock on wood), so can't help you there.
Good luck!
Another version of the Bendix Service Manual, which may be even closer to the system in our coaches:
http://www.wanderlodgeownersgroup.com/downloads/BendixCruiseControl%20Service%20Data.pdf
Thanks everyone. I've ordered a new TR-3 valve as well as a rebuild kit for the CC-5. I'll check out the rest of the system while I'm in there and will let you know how this resolves.
@debugjaws Gerry,
Where did you order the rebuild kit for the CC-5?
It is helpful to include a link to your source any time you post about ordering hard-to-find parts. That way, when another member (with the same problem) is reading this thread a couple months later, he won't have to spend hours searching for the same source. It's just a way to make each thread more valuable to the whole community.
Here is the service manual for it I think SD-10-1
Gives you all the things to do etc.
Hope this is yours.
Edit----Sorry, I did not open that PDF file and see it was the same manual.
Gerry, me too, I've tried for over a year.
Where did you order the rebuild kit for the CC-5?
Thanks Mack C.
IO would have taken it apart before ordering cylinder parts as I seem to remember it is only O rings that are available everywhere. Plus some synthetic grease for cylinder wall.
I very much doubt the Pot' needs replacing
JohnH
Happy to provide that information. I simply did a google search on "Bendix 102315". There are a number of suppliers out there that say that they can provide the parts. I got these through "Find It" parts - Heavy Duty Truck Parts Online, Medium Duty, Light Duty - FinditParts (http://www.finditparts.com). But "PartsRiver" and "TruckPartsWarehouseOnLine" all claim they have it; and by have it I'm pretty sure they mean "order" it from Bendix - as the FindIt folks did. BTW - they also had the valve, 101781N ... actually in stock ...
Hi Mack ... "FindIt" parts is where I got them. Heavy Duty Truck Parts Online, Medium Duty, Light Duty - FinditParts (http://www.finditparts.com). I did a google search on the part numbers (102315 in this case) and these guys amongst a number of others showed up as carrying them. They had to order the kit from Bendix. It will be here in a couple of weeks. Now that said, as you'll see by reading this thread and others, people say that it mainly consists of O-rings. So if you're comfortable sourcing your own O-rings you can save probably $35.00 of the $41.00 that I paid. But o-rings can be specific in ID, OD, thickness, and material - so I went for the kit.