Mountain Driving with 1995 42', 42,000 lb. Blue Bird
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06-25-2007, 12:58
Post: #11
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Mountain Driving with 1995 42', 42,000 lb. Blue Bird
The 42,000 is empty; no liqiuds, tools, dishes, water, pans , people,
etc. Comfortably provisioned, you should be over 45,000 and you need to be under 48,900, the max. weight. Get the coach weighed at each tire to see how it is balanced and what your actual weight is. Tom McCarthy 95 PT42 Poway, CA --- In WanderlodgeForum@yahoogroups.com, Ron Thompson wrote: > > I don't know about the new ones but mine is a 1995 and the body tag says 42,000 lbs. My guess would be that it is probably heavier than the new ones. They are taking weight out of them to cut the cost of production. > > Just my thoughts./ > > Regards, > Ron Thompson > > erniecarpet@... wrote: Ron, I may be wrong but don't the newer coaches weigh more then the 42,000 > pounds? > > Ernie Ekberg > 83PT40 > Livingston, Mt > > ************************************** See what's free at http://www.aol.com. > > [Non-text portions of this message have been removed] > > > > > > > > > [Non-text portions of this message have been removed] > |
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06-25-2007, 12:58
Post: #12
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Mountain Driving with 1995 42', 42,000 lb. Blue Bird
I'm no expert, but I've crossed the Rockies in southern Wyoming
twice, I've done the Raton pass in southern Colorado twice, I've gone up and back down Colorado I-70 to near Evergreen CO, and I've crossed the Sierras into California on I-80. Plus I've traveled through a fair number of lesser mountains in Oregon, Idaho, and California. So I've seen a few mountains. Basically, the technique is to watch the temperatures, especially the oil temp when you're climbing. Higher revs = cooler engine, so slow down and shift down, as necessary. Take it easy. Coming down, use the jake brake (it's actually integrated into the automatic transmission, so when it's enabled, it 'kicks in' as needed. The engine computer "watches" the revs to avoid over-reving but you still need to watch that you don't exceed 2400 RPM while exhaust (Jake) brake is operating and 2100 RPM while under power. In general, come down at moderate speed. When you slow down with the service brakes, slow to 5 mph or more _below_ your target speed, then let the coach gradually pick up speed (still using the jake brake). The coach has plenty of service brake capacity to control the vehicle ... but you do need to pay attention an not run low on air. Don't "ride" the brakes as that will heat them up and not really help maintain control. It is said that you should descend at the same speed that you climb at ... but the reality is somewhat different. For example, from Reno to Donner Pass on I-80 you climb about 3500 feet in 10 miles or so. Then from Donner Pass to Roseville, you descend nearly 7000 feet in 40 miles. So, the grades are quite different and your speeds will not be "the same"... Nevertheless, "keep it moderate" is a wise approach. If road-side signs suggest a curve be taken at 40 mph -- take it to heart. It's good advice. Be sure to get to 40 or slower for that curve. (For years, I always wondered just who they were thinking of with the curve-speed advisories. Now I know....) Note: Do not use the jake brake under poor traction conditions (such as snow or wet pavement) as it can lead to control/skidding problems. Pete Masterson '95 Blue Bird Wanderlodge WBDA 42 aeonix1@... On the road at Harrisburg Oregon On Jun 25, 2007, at 12:28 PM, Ron Thompson wrote: > This is a question that lots of people might want to explore. Would > someone with a lot of experience driving a big rig in the mountains > please write up a good descriptive instruction for mountain driving. > > I have never driven in the big mountains with a normal vehicle much > less a 42,000 lb motor coach. I am planning a trip through the > mountains maybe this year but definitely next year from Texas through > the Rockies and on up to Alaska. It would sure be helpful to have > some pointers from an expert. > > Best regards, > Ron Thompson > |
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06-25-2007, 13:08
Post: #13
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Mountain Driving with 1995 42', 42,000 lb. Blue Bird
The "jake brake" on the '95 with the Series 60 engine is a true
"exhaust" brake and it generates no excess heat energy that must be handled. It is not a magnetic brake like those used on earlier 'birds. The brake system is integrated with the automatic transmission. You flip the "enable" switch on and set the "intensity" switch to low, medium, or high. When you take your foot of the accelerator pedal, the jake kicks in. The transmission will shift down (if within a safe RPM range) to the next lower gear to strengthen the braking effect, depending on the position of the low/med/high switch. If you then press on the accelerator pedal, the jake shuts off and (after a brief delay) the transmission will up-shift to ensure that the RPM will be in the safe range. I note that on my coach, someone has wired-out the medium setting so that I have the choice of either high or low, but I'm usually able to find a balance on most grades that's satisfactory. Pete Masterson aeonix1@... '95 Blue Bird Wanderlodge WBDA 42' El Sobrante, CA On Jun 25, 2007, at 3:43 PM, brad barton wrote: > <snip> If you have a magnetic retarder, be aware that it will build > up considerable heat if used for several minutes..so downshift to > help it out. I don't think your Jake brake or Pac brake is limited > that way but a diesel mechanic can be more specific. <snip> > |
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06-25-2007, 13:15
Post: #14
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Mountain Driving with 1995 42', 42,000 lb. Blue Bird
Without digging out my blue box, The maximum allowed GVW of the '95
is around 52,000 lbs. The approximate "curb" weight is around 42,000 lbs. (That may or may not count water and holding tanks -- I'd have to dig out the book to be certain.) As typically loaded, I'd expect that most would weigh about 46-48,000 lbs. Pete Masterson aeonix1@... '95 Blue Bird Wanderlodge WBDA 42' El Sobrante, CA On Jun 25, 2007, at 4:12 PM, erniecarpet@... wrote: > Ron, I may be wrong but don't the newer coaches weigh more then the > 42,000 > pounds? > |
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06-25-2007, 13:44
Post: #15
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Mountain Driving with 1995 42', 42,000 lb. Blue Bird
The Jake Brake or Jacob Brake is a particular brand of engine brake
manufactured and sold by Jacobs Vehicle Systems, Inc. While the term Jake Brake technically only describes Jake Brake brand engine brakes, it has become a genericized trademark and is often used to refer to engine brakes or compression release engine brakes in general, especially on large vehicles or heavy equipment. See Wikipedia for a full entry at: <http://en.wikipedia.org/wiki/Jake_brake> The magnetic retarder used on some earlier BBs is similar to the technology used for "dynamic braking" on diesel-electric railroad locomotives. The diesel-electric locomotive is actually a diesel generator (up to 5000 HP) that powers electric motors to drive the engine. On down grades, the motors are electrically switched to become generators, and the power produced is directed to very heavy duty grids and discarded as heat. Realize that these things produce 600 amps at 600 volts and that's a _lot_ of heat! (Great for toasting marshmallows.) Pete Masterson aeonix1@... '95 Blue Bird Wanderlodge WBDA 42' El Sobrante, CA On Jun 25, 2007, at 4:28 PM, Ron Thompson wrote: > My BB has an engine retarder. I have no idea what that is > exactly. I assume it is using the compression of the engine to > hold back the transmission which will hold back the BB > > What is a Jake Brake? > <snip> |
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06-25-2007, 13:55
Post: #16
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Mountain Driving with 1995 42', 42,000 lb. Blue Bird
up to 1200 amps at 480 volts but don't do that on a curve or you get
to see the wrong side of the tree line we are limited to 500 amps on heavy curves you have to use a combination of train brake and dynamic on 2%or more grades --- In WanderlodgeForum@yahoogroups.com, Pete Masterson wrote: > > The Jake Brake or Jacob Brake is a particular brand of engine brake > manufactured and sold by Jacobs Vehicle Systems, Inc. While the term > Jake Brake technically only describes Jake Brake brand engine brakes, > it has become a genericized trademark and is often used to refer to > engine brakes or compression release engine brakes in general, > especially on large vehicles or heavy equipment. See Wikipedia for a > full entry at: > <http://en.wikipedia.org/wiki/Jake_brake> > > The magnetic retarder used on some earlier BBs is similar to the > technology used for "dynamic braking" on diesel-electric railroad > locomotives. The diesel-electric locomotive is actually a diesel > generator (up to 5000 HP) that powers electric motors to drive the > engine. On down grades, the motors are electrically switched to > become generators, and the power produced is directed to very heavy > duty grids and discarded as heat. Realize that these things produce > 600 amps at 600 volts and that's a _lot_ of heat! (Great for toasting > marshmallows.) > > Pete Masterson > aeonix1@... > '95 Blue Bird Wanderlodge WBDA 42' > El Sobrante, CA > > > > > On Jun 25, 2007, at 4:28 PM, Ron Thompson wrote: > > > My BB has an engine retarder. I have no idea what that is > > exactly. I assume it is using the compression of the engine to > > hold back the transmission which will hold back the BB > > > > What is a Jake Brake? > > > <snip> > |
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06-25-2007, 14:39
Post: #17
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Mountain Driving with 1995 42', 42,000 lb. Blue Bird
The true 'Jake Brake' is an integral part of the engine design. It
alters the exhaust valve timing to use the exhaust stroke for compression braking as well as the normal compression stroke. It makes a very distinctive loud sound when the exhaust valve is opened late. You most likely have heard it whan an 18 wheeler is behind you on a down grade. This system provides a significant braking effect. An exhaust brake simply blocks the exhaust pipe. Since the volume of the exhaust pipe is significantly greater than the cylinder in the engine, there is far less resistance to the exhaust stroke and equally less braking effect. A retarder is an electronic or hydraulic device that provides resistance to the drive train. These systems generate a lot of heat and need to be used in conjunction with the service brakes to distribute the braking load. Whatever system your coach has, take the time to understand how it works and how to effectively use it. Don't assume that it will work all by itself without your understanding. --- In WanderlodgeForum@yahoogroups.com, "Stephen Birtles" > > up to 1200 amps at 480 volts but don't do that on a curve or you get > to see the wrong side of the tree line > we are limited to 500 amps on heavy curves > you have to use a combination of train brake and dynamic on 2%or more > grades > > --- In WanderlodgeForum@yahoogroups.com, Pete Masterson > wrote: > > > > The Jake Brake or Jacob Brake is a particular brand of engine brake > > manufactured and sold by Jacobs Vehicle Systems, Inc. While the term > > Jake Brake technically only describes Jake Brake brand engine brakes, > > it has become a genericized trademark and is often used to refer to > > engine brakes or compression release engine brakes in general, > > especially on large vehicles or heavy equipment. See Wikipedia for a > > full entry at: > > <http://en.wikipedia.org/wiki/Jake_brake> > > > > The magnetic retarder used on some earlier BBs is similar to the > > technology used for "dynamic braking" on diesel-electric railroad > > locomotives. The diesel-electric locomotive is actually a diesel > > generator (up to 5000 HP) that powers electric motors to drive the > > engine. On down grades, the motors are electrically switched to > > become generators, and the power produced is directed to very heavy > > duty grids and discarded as heat. Realize that these things produce > > 600 amps at 600 volts and that's a _lot_ of heat! (Great for toasting > > marshmallows.) > > > > Pete Masterson > > aeonix1@ > > '95 Blue Bird Wanderlodge WBDA 42' > > El Sobrante, CA > > > > > > > > > > On Jun 25, 2007, at 4:28 PM, Ron Thompson wrote: > > > > > My BB has an engine retarder. I have no idea what that is > > > exactly. I assume it is using the compression of the engine to > > > hold back the transmission which will hold back the BB > > > > > > What is a Jake Brake? > > > > > <snip> > > > |
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06-25-2007, 15:57
Post: #18
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Mountain Driving with 1995 42', 42,000 lb. Blue Bird
Just an add on " you do not ride the brakes.. You apply continuous gentle
pressure to slow the vehicle. As I said earlier if you smell brake you are in to high of a gear. Slow down before you mow down some one else. "Mountain driving - Professional drivers are taught to use the same transmission gear to descend a grade as the one required to climb the grade. This is a good rule of thumb but road surface conditions, visibility, and other variables must be used. Proper use of an exhaust brake will save the service brakes for real emergency stops. If you must use the service brakes it is better to keep a continuous light application of the brake pedal. This is less likely to cause brake fade than to allow your vehicle to speed up and then pump your brakes to slow it down. Better yet descend in the correct gear so that you don't even have to use the service brakes. It may take a few seconds longer to get down, but at least the brake lining will be saved and you won't have white knuckle brake fade to deal with. If your brakes do fail, look for a run off ramp designed for that event. If none is available try to scrub off speed by side swiping the mountain edge of the roadway. It is better to damage the rig than to go off a steep embankment and roll over, etc. Proper maintenance will significantly reduce this risk and you could take a few seconds in the Brake Test Area on the top of the hill to inspect and test your rig's brakes and tires. A few seconds is all it will cost. " 5.4.6 Proper Braking Technique Remember. The use of brakes on a long and/or steep downgrade is only a supplement to the braking effect of the engine. Once the vehicle is in the proper low gear, the following is the proper braking technique: . Apply the brakes just hard enough to feel a definite slowdown. . When your speed has been reduced to approximately five mph below your "safe" speed, release the brakes. (This application should last for about three seconds.) . When your speed has increased to your "safe" speed, repeat steps 1 and 2. For example, if your "safe" speed is 40 mph, you would not apply the brakes until your speed reaches 40 mph. You now apply the brakes hard enough to gradually reduce your speed to 35 mph and then release the brakes. Repeat this as often as necessary until you have reached the end of the downgrade. Both methods work if you are in a low enough gear. Jim Hutchings From: WanderlodgeForum@yahoogroups.com [mailto:WanderlodgeForum@yahoogroups.com] On Behalf Of Pete Masterson Sent: Monday, June 25, 2007 6:44 PM To: WanderlodgeForum@yahoogroups.com Subject: Re: [WanderlodgeForum] Mountain Driving with 1995 42', 42,000 lb. Blue Bird The Jake Brake or Jacob Brake is a particular brand of engine brake manufactured and sold by Jacobs Vehicle Systems, Inc. While the term Jake Brake technically only describes Jake Brake brand engine brakes, it has become a genericized trademark and is often used to refer to engine brakes or compression release engine brakes in general, especially on large vehicles or heavy equipment. See Wikipedia for a full entry at: <http://en.wikipedia.org/wiki/Jake_brake> The magnetic retarder used on some earlier BBs is similar to the technology used for "dynamic braking" on diesel-electric railroad locomotives. The diesel-electric locomotive is actually a diesel generator (up to 5000 HP) that powers electric motors to drive the engine. On down grades, the motors are electrically switched to become generators, and the power produced is directed to very heavy duty grids and discarded as heat. Realize that these things produce 600 amps at 600 volts and that's a _lot_ of heat! (Great for toasting marshmallows.) Pete Masterson aeonix1@... '95 Blue Bird Wanderlodge WBDA 42' El Sobrante, CA On Jun 25, 2007, at 4:28 PM, Ron Thompson wrote: > My BB has an engine retarder. I have no idea what that is > exactly. I assume it is using the compression of the engine to > hold back the transmission which will hold back the BB > > What is a Jake Brake? > <snip> [Non-text portions of this message have been removed] |
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06-25-2007, 21:06
Post: #19
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Mountain Driving with 1995 42', 42,000 lb. Blue Bird
James,
We were talking past each other. Steady pressure for a few second to slow down is not the same as riding the brakes or pumping the brakes. You're right. Brad Barton 00LXiDFW bbartonwx@... _________________________________________________________________ Live Earth is coming. Learn more about the hottest summer event - only on MSN. http://liveearth.msn.com?source=msntaglineliveearthwlm [Non-text portions of this message have been removed] |
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06-25-2007, 23:34
Post: #20
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Mountain Driving with 1995 42', 42,000 lb. Blue Bird
Randy,
Yes, I have a Detroit Series 60 Diesel with Allison World 6 speed transmission with the Engine Retarder, which I guess is what you call the Jake Brake. I assumed that it closes the valves and turns the cylinders into a compressor thereby holding the coach back. I can see where that would be an effective process. Thanks Randy for clearing that up. Jake Brake was a new term to me and I wasn't sure that what I had was a Jake Brake. It is all switch controlled though. Thanks for the input. Regards, Ron Thompson Waller, Texas (near Houston) martingregg598 Ron, if you have a Allison HT-755 five speed with a retarder, I have know advice, if you have a 1995-42' you should have a Allison HD-4060 and a DD series 60 with a 3 position Jacobs engine brake. Jacobs's brakes close the valves and turn the cylinder into a compressor creating braking horsepower, each position adds more cylinders. I haven't driven a 95 in the mountains but I have driven over a lot of the passes in the Cascades, Montana, Idaho and so on, but I can't imagine that if your in the right gear at the right RPM that the engine brake won't hold it back. For me with a less effective Pac Brake, it is 4th gear at 50 mph at about 2400 rpm's on a 6% or so, on a steeper grade it's 3 gear at 35-40 mph and I almost never have to use my air brakes. If I am in 4th and it starts to run away, faster that I like, I use the brakes to get the coach down to the speed that I can select the next lower gear. If the Jacobs brake doesn't hold you back, maybe there is something wrong with the Jacobs brake? As for the "Drum type" air brakes, if you have been on the road for a time and the ambient temp. is hot, and If you ride the brakes for a long period of time the drum can expand away from the shoe and you lose your brakes. With some real bad luck you could heat the wheel up so hot that it heats the tire up and blowout. Marty 95 BMC 37 Kennewick Wa [Non-text portions of this message have been removed] |
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