BAC Forum
General Boards => Technical Support => Topic started by: Lawrence Tarnoff on May 09, 2015, 02:15:26 AM
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Uneventful 200 miles to our State Park destination. A couple of observations: you can't get lazy with the steering wheel as it requires almost constant correction.
Also, the dash air-conditioning is pitifully weak. Is there a way to run the roof air conditioner while underway?
Only one gotcha -- the inside leveler controls did not work. Had to level the coach from the basement control panel.
Bottom line -- this is magnificent!!
Larry
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Larry,
Doesn't sound too bad for day 1 in a 1999 (mine is a 1999). My coach's air didn't work at all, but a charge was all it needed.
The leveling system may simply have come detached right at the control panel in the coach. Should be easy to unscrew it, and reconnect it. I say this because my coach had a similar issue. Another time the connection inside the controller box (in the electrical basement cabinet) had come undone.
As long as you start your generator, you should certainly be able to run your roof air.
Have a great time!
Mike
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Larry,
Only way to travel! With the age of your coach, the steering box is probably worn, resulting in excessive steering play. You can correct this to some extent by tightening the steering box adjustment screw on the side of the box. You have to loosen a keeper nut to be able to turn the screw. Turn it about 1 turn max and see if that improves things. If you get it too tight the steering will get very touchy. Then back it off a bit.
Your dash A/C may need a can of freon. If you can locate the low pressure side of the system (normally capped with a blue cap) you can check and add a can from Auto Zone, etc. They usually supply the gauge and hose connection. You can use you roof AC on the road by running your generator while traveling. IN the summer, it's about the only way to keep the coach comfortable during the day.
If you inside leveler controls aren't working at all, I'd check to see that the circuit has power. I had a similar problem on our Contessa and found the circuit board was cracked where power came in.
Happy travels!
Steve
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Larry,
Steve jogged my memory regarding the steering in my 1999. I had new tires put on, and afterward I had to keep moving the wheel a little back and forth. My problem was air pressure as the guys had put 105lbs in it at 48 degrees, so it was now too high. I found that 105lbs at about 65-70 degrees was right for my coach and the steering was much easier.
The problem for me with this coach is that I've never driven anything similar. I've had a 34' Winnebago gasser, and this one drives and feels like night and day compared to the bouncy ride and firmness on the road. The Winnie did steer better than an older 25' gasser we first had. But my understanding is diesel pushers drive much better, so I was concerned about having to move the wheel back and forth so much, rather than simply rest my hands on it, and I was glad the tire pressure change made a difference for me.
I'd like to drive some other owner's coach at some point (which is similar to mine) and see what the difference is. Short of that, I may stop past Grant's Pass, Oregon at Henderson's Line up one of these days and pay for their test ride.
Mike
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I have to echo Steve's opinion re. the steering box wear - your rigs are 16 years old. You should heed the advice about adjustment. But a trip to Hendersen's, if possible or opportune, is a very good objective.
Joel
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Steve and Joel,
My coach has about 67,000 miles on it. Even though it was born in August, 1998, wouldn't steering box wear be a result of use rather than sitting? When does a service like this take place in the normal course of things? Would this be something done at every grease job? Is this something that someone greasing the coach could/would do?
As I said, my steering is now ok, merely having adjusted the air pressure lower in the tires. I certainly don't want to miss a maintenance step, however.
Thanks you two.
Mike
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Mike,
Steering gear adjustment is a wear or repair item that is only done if there is a problem, and never as part of a lubrication. My coach has nearly 150,000 miles an I have never adjusted the steering gear because it was not needed.
You said that you lowered the air in your front tires. This can be dangerous if you have not weighed the coach to be sure that you are not overloaded at the lower air pressure. I run 120 PSI in all my tires because it is required to support the weight of my coach. There have been many coaches that have been damaged or even totaled because of underinflated tires. Never run underinflated tires.
Gerald
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Hi Gerald,
This is probably going to get me in trouble, but I run Double Coin 606+ tires all around - is that laughter I hear from the community? :), and those tires are rated to carry my weight at 105lbs (Duals 5840, Single 6175).
Now, having admitted to purchasing Chinese Tires, I do regret now that the tread depth was deeper 22/32nds than the Michelins and other tires I looked at which were 19/32nds. I thought having a bit more tread might be nice, but they are noisier than the Toyos I took off with 20,000 miles and 10 years on them.
Mike
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Mike,
If you are taking the weights from the tire placard by the driver's seat, do not trust it. Weigh you coach at each individual wheel. That is the only safe way to set your tire pressure. My coach weighs about 3,000 pounds more than the placard states.
Gerald
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Gerald is correct in his statement about the correct tire pressures. Tires pressures are one of the most
over looked part of motorhome travel in today's world. Having experienced a left front blowout at
65 mph and taken motorhome into oncoming traffic lane. Happened about 5 years ago on two lane road. Today I have a tire shop handle my tire maintance and rotation , reason I have a paper trail in
Case of what happens if. Correct tire pressures. Rotation of tires, correct torque of wheel nuts. In many cases you will find the inner duel rear wheel are loose. It is the cost of ownership and is peace
of mind knowing what your rolling down the road on. Dave Atherton.
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Mike,
I just experienced an inner dual blowout on a return from TX just west of Van Horn. While Coach Net was GREAT in getting me a tire replacement service (less than 45 minutes from blowout to arrival of tire outfit), it cost me about $400 for a replacement. Additionally the blowout took out an airbag so getting home was "fun". Failure of the tire was a "zipper" fail where a sidewall separated. This is normally due to low air pressure. First thing I did on getting home was to buy a TPMS (tire pressure monitoring system). (The total cost of the repair was much more than the TPMS cost). Get one!
Steve
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Larry
Our coach was loosy goosy and after some shop time we found out that the Pitman arm was loose where it attaches to the steering box. Thing is because it is mounted with a lock collar and nut not to mention dirt, you could not tell it was loose until your hand was on it and the steering wheel was moved. It was so loose it could almost be lifted right off the splines. A good tightening resolved nearly all the steering difficulty. If that had popped off, bye bye steering.
I have never heard of anyone else with this problem but checking it out is cheap!
Travel well be safe.
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When we bought our 2000 PT the steering was not very good and pulled like crasy if I drifted over to the the right rumble strips. When we got home I had the 10yo toyos replaced and the front and rear axles aligned. The right front tire was badly scalloped on the inside and the front alignment was way out of wack....toe-in I think was the main culprit.
Once it had a new set of Hankook shoes, balanced, and aligned it was a night and day difference. Not hands off steering but still very easy to drive with virtual no drifting.
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I guess we've drifted from the original subject, but tires have always been a huge subject for coaches.
One of the first things I did was to get a TPMS as part of my update to my coach. I'd read all the horror stories, and at least with a TPMS, I could easily check pressures any time I wanted to. I'm also not one to go over about 57 miles per hour typically in the driving I do (note that's the 6th gear changeover speed in economy mode), though my cross country trip did sometimes see 60-65 but not for long. I'm not in a hurry - and my wife is certainly not in a hurry :).
Since we're on the subject of tire pressures, and we all know they change according to temperature, and that the tire manufacturers and vehicle makers prescribe a certain tire pressure as being MAXIMUM tire pressure for a tire, at what temperature do they mean?
Do you have to take air out at 75, 85, 105 degrees, lest the maximum is exceeded? Then put it back in, when the sun goes down?
I'd read some place that 65 degrees was the temperature the maximum is alluding to, but haven't been able to find that reference again - only the word AMBIENT. That's the temperature I use as a base line and for my coach and tires at that temperature, its 105lbs, and this based on my experience in the coach going across country. I'd seen pressures on the TPMS as high as in the low 120s while travelling. What are others seeing on the TPMS?
Mike
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Mike,
See http://beaveramb.org/forum/index.php/topic,4449.0.html for a discussion on pressure v temperature. I was asking same question. Decided to use ambient of about 85-90 as that is prevalent temp in my shop for at least half the year. I will use Joel's forumla to verify PSI on TPMS at different ambients but will not deflate tires at higher temps.
Steve
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Thanks Steve,
I'd have to conclude from that discussion that there seems to be a choice. Mine is to keep mine at 105lbs at 65 degrees. The 105lbs is based on the weight rating of my coach, that I don't think I am coming close to (I haven't yet tried to weight it but will try soon), and the 65 degrees was just the number I'd read, but haven't found again. Evidently Gerald found 60 degrees, and his tires spec out to 120lbs for his weight see -
http://www.rvtirepressure.com/assets/images/extrapages/Michelin_Rv_Load_Inflation.pdf (I assume this is Michelin's recommendations).
If I am reading that right, then with Gerald's 295/80/22.5s (see other forum thread), 120lbs would allow a total weight of over 43,000lbs. I believe my weight is considerably less, probably at about 33,000lbs. So, it just all depends I guess.
I have the TST TPMS system with flow through valves, and supposedly it measures temperature and pressure, and if so, and if accurate I am seeing more than 1.7 PSI per 10 degrees difference. But I don't honestly trust the temperature sensor portion of this setup, as I would think the temperature would be affected more by the heat generated by the road surface, when in fact, it appears to be affected by which side of the coach the sun is on. In other words its measuring the temperature of itself, not the air in the tire. When one thinks about it, how could it measure the temperature of the air in the tire?
Good discussion,
Mike
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Mike,
As Gerald noted earlier, weigh all 4 corners of your coach fully loaded. Full fuel and water tanks. I also fill the black tank about 70% to simulate a loaded reefer and clothes, etc. The loaded weights can vary significantly from right to left. For example, on our 2000 Marquis; FL is 6440 and FR 6140. RL is 11880 and RR 10600. Our 01 Contessa had similar variances. FL; 5228, FR 4866. RL 9904 RR 8520.
Steve
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This is a tire pressure chart that Ed Buker sent to me that should answer your questions about the ambient temperature and pressure correlation.
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This is going to sound sarcastic but I really don't mean it that way! Anyway, these coaches are not designed for engineers and atmospheric scientists. Surely They can't expect a dumb old street cop like me to do all these calculations every time I fill my tires? Can they? I do realize that this is important stuff. I put 120 in my tires as the placard says but I don't take outside temp into account and I surely don't stop in 100 miles on a hot day to let some air out to get down to 120. As I said above, dumb old street cop here, should I really do all that stuff? I'm still learning tons of stuff from you guys and gals so keep it up. Thanks.
Jerry
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Jerry,
You missed the point that cold inflation is at 65 degrees, and you should not deflate your tires if the weather is warmer than 65. Also, you should never deflate a hot tire to the cold inflation point because that will result in a dangerously underinflated tire.
Gerald
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Jerry,
You missed the point that cold inflation is at 65 degrees, and you should not deflate your tires if the weather is warmer than 65. Also, you should never deflate a hot tire to the cold inflation point because that will result in a dangerously underinflated tire.
Gerald
I warned you that I was a little slow! I've seen these discussions on other forums and I always wonder why folks just don't put the correct amount of air in their tires and be happy. I realize that there are two ways, 4 corner and placard, to set them. So you have confirmed that I am not as dumb as I thought.
Thanks
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Jerry,
Somehow the tire manufacturers have to calibrate the weight capacity vs the pressure that you need to support your weight by axle. The issue is, that value varies by temperature, so they set the cold inflation pressure at 65 degrees as a calibration reference.
So by the chart, lets assume that the tire manufacturer says you need 100lbs of air in the tire at 65 degrees. Lets also assume that you are checking the tires before leaving a campground and it is now 85 degrees outside. By the chart the cold inflation pressure you should be seeing is now 105 lbs to be equivalent to 100lbs at 65 degrees. So if you see 105lbs, that is perfect. If you see 100lbs you are 5lbs underinflated. If anything this chart has you not chasing a single cold inflation value at other temperatures when you do not need to.
When it is very cold or very hot this chart should be a help to know when pressure changes are a real issue or just a result of temperature change. Hope this helps.
Later Ed
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I used to have Michelin 295/80R22.5 tires on the front and tried to maintain 120 - 123 psi cold. At times after an hour or so on the road I have seen increases to 138 - 140 psi on my TPMS. This past Fall before going South for the Winter I put Dunlop 315/80R22.5 tires on the front to increase the carrying capacity. At 130 psi cold these tires carry about 9k pounds each as compared to the 295s at about 8.25k pounds each at 120 psi. There is no noticeable ride nor noise difference between the two sets of tires. The other six tires need to be scheduled out due to age later this year or next.
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David,
You may want to check your rims, some aluminum versions may have a max cold pressure of 120lbs written on them.
Later Ed
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This is a tire pressure chart that Ed Buker sent to me that should answer your questions about the ambient temperature and pressure correlation.
As I read the information below the chart, it appears to be saying that you should inflate your tires to the recommended cold inflation pressure regardless of whether the temperature is below 65 degrees. I've been simply looking at mine, knowing I have at least 105lbs in at 65 and that all tires are pretty identical on the TPMS except 1, and if its 48 degrees outside, and all tires but one are showing 99-100, and the other tire is showing 95, I fill it to 100. Should I be filling it to 105lbs? That doesn't make sense to me but appears to be what the wording beneath the chart says.
Jerry, I agree with your point, yet, I see the wording on the side of my coach that says something like "proper wheel lug tightening is the owner's responsibility" or something like that, and its just funny, as I don't have the equipment to tighten or loosen the lugs. I suppose the bottom line, as always, is litigation, or the possibility thereof, so there are lots of warnings, making it appear to the common individual that they have no chance of using one of these coaches in a responsible and safe manner. :)
Mike
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Mike,
Without making yourself too crazy over tire pressure, I and most people know the weights of thier coach and have added in a 5lb to 10 lb safety margin into the 65 degree cold inflation pressure. If that is the case you would just bring the 95lb tire, that is different and low, up to be the same as the other one on that axle. Below 65 degrees in general they want you to use the cold inflation pressure value but at what temp you would care about that is up to you and your tire position weights and the air pressure vs load safety margin you may have chosen. If it was zero out and you are planning on traveling you may want to have all the pressures compensated some.
The way I look at this is I may compensate one time during the cold months to get the tires about right and in the warmer travel months you keep the tire pressure on the same axle even. You can glance at the chart and know by temperature what they should be reading and not over or under compensate if you think it is time to add air because the pressure would be too low at 65 degrees. I personally add air if any tire in an axle position is 5lbs low, given my safety margin and I try and keep them within 2 lbs of each other on an axle. Tires lose air at a very slow rate if all is well so a compensation over a few months is normal. If you have a tire that loses air at a rate that is worse than others or has changed its air loss behavior, you need to get that taken care of right away. You do not know why and what it means will happen next.
As always, know what is the right pressure and manage it accordingly. Low pressure in an RV tire is not at all like a car. It is a true hazard because low pressure causes the sidewalls to flex back and forth at greater angles. There are hundreds of steel cables in the sidewall spaced about 1/4 inch apart and with that more severe flex angle, it can cause them to fatigue and break. Bending a wire severely back and forth is a good way to visualize this metal fatigue issue. It only takes one low pressure drive to ruin an RV tire. So managing tire air and tire age is probably the single most important safety issue for you and your family while on the road.
At these pressures steel cables hold the tire structure together and rubber holds the air. If the steel cables fail the rubber rips apart. If you lose a front tire you may lose control of the coach and lose your life. A car tire has no cables in the sidewall and can handle this low pressure issue much better. Hope this helps.
Later Ed
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Since we are on the topic of tires......Thought this was an amazing video to see that happened a couple days ago.... I nearly experienced the same with a left front blow out a year ago but luckily had another traffic lane to my left and not a grassy median.... Not sure what caused this guys blow out, but if checking my coaches weights and the tire pressures can help prevent that from happening I'm definitely not gonna short cut in that area ever.
Nobody was seriously injured as a result thank goodness.
http://youtu.be/9LkLeljt4t0
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Great way to make a point Matt. Thank God he was in an open area unlike some of the related posts on this forum.
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I'm wondering if the driver in the video was ever advised of what to do in the event of a blow out. It appears that he hit the brakes which is a normal reaction. The correct thing to do is apply throttle until you know you have control and then slow down gradually. Braking just magnafies the sudden change in tire pressure and assures that the coach will go in the direction of the blow out. I put 12R bus tires on my coach because I don't ever want to be put in that kind of situation. Interesting conversation in this post so far.
Regards Fred
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Wow! Interesting video. But Fred, I did not see the brake lights come on. It is amazing how quickly he lost control. Scary.
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Wow! Interesting video. But Fred, I did not see the brake lights come on. It is amazing how quickly he lost control. Scary.
If you look closely you can see where he tapped the brake just before everything went to s--t!!
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A Safe-T-Plus or other stabilizer helps in these situations, and he might have remained in control and on the highway with one. A front blowout is the worst. I didn't see brakes either, and he might have been trying to keep the power there to pull out of it. But that median cable caught his front end and after yanking out a bunch of cable posts it finally grabbed enough of his right side down low to turn and flip him.
Sans the cable he either would've straightened and slowed in the median or crossed into a head-on. Given his direction when he hit it, the cable actually helped straighten him and probably saved some lives ultimately, but then his momentum couldn't overcome the low right side resistance.
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Right rear signal came on at exactly the same time the tire blew. Very strange indeed. Seems like he was getting ready to move back to the right lane right at the blowout time and reacted wrong by using the brakes losing control.