BAC Forum
General Boards => General Discussion => Topic started by: Jason Worman on September 10, 2018, 04:32:30 AM
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Hi All,
After 5 grueling months of coach repair and remodeling we take out our rig on our first roadtrip up the Oregon Coast to Cape Lookout. Any advice for newbies going on our first road trip. Thanks
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Jason,
There are two things about living in a RV, the trip and the destination, SLOW DOWN and enjoy both of them.
Gerald
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Jason. Our first Beaver was the 1991 Contessa. My advice is to be sure you have looked at the Radiator as on ours it actually disintegrated and when pulling hills and long drives it overheated. The fins when touched just fell off. When we finally replaced we also increased the size of the transmission cooler and also replaced the after cooler radiator. It is not an easy job but never had to do again as we replaced in 1996 and had the coach for 18 years. Numerous places you can get good radiators etc other than at dealers.
Going up long grades in mountains used to boil out the transmission fluid and is why we upsized all the cooling radiator.
If you have trouble with the cruise you can rebuild it quite easily with a little care and some available parts.
My advice on the Onan 6K gen set was to keep it running, do not replace as it is one of the better made Onans compared to todays units. Do not worry if it leaks a little oil, was my electrical shops advice.
There are 3 zerks on the steering, two on the column under the cover by your feet and one on the side of the housing under the coach. Keeping them greased helps the wander being reduced.
We had on occasion a would not start situation. Even when we had just ran 800 miles and stopped in to pay for campsite. The fuel water seperator has O rings that like to dry out and you get air instead of fuel. The oblong glass unit looks great - but bubbles on the top tell the tale. Just carry spare and replace if that happens.
It is all drums and we had the drums turned by a shop instead of buying new as they are not your standard drums from a truck. New pads after turning drums and it had excellent brakes back. You will probably have to look hard to find an old shop that will turn them but it is well worth it.
Any other questions do not be afraid to call me 231-218-1119 or email at douglasallman@gmail.com
We put well over 100,000 miles on that unit from Michigan to the Florida & the Pacific Coast on many trips.
If you have a question on the 3116 be sure to talk to Dave Atherton. He is the Dave in the ASK DAVE section on the Forum. 42 year retired CAT mechanic.
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Doug,
Thanks for the information, will inspect those items before leaving tomorrow. We have driven it about 500 miles locally, so far no problems.
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Jason, our first Beaver was a 1991 Baronet with the 3116. We owned it 3 years and put 35000 miles on it. I found that staying right at 55 mph we got between 10-11 mpg pulling an open car trailer with an 06 Hyundai Azera every mile we put on it. We really enjoyed that coach just had a floor plan that wasn’t our favorite. On the Baronet the brakes had manual slack adjusters, make sure if you have those to adjust them properly and every oil change, my 1991 Marquis has automatic adjusters. I changed that transmission fluid over to Allison synthetic, as others stated on long hard uphill pulls the transmission temp would just hit the alarm point, about 240 degrees, with synthetic I was more comfortable with that temperature. I had the overhead run, valves and fuel injectors adjusted when we got ours with about 80,000 miles on it, Dave Atherton told me that it wouldn’t need done again for another 350,000 miles. Having a mechanical fuel injected diesel in my opinion is a big plus, no strange electrons running around to make the engine do crazy things, I just used CAT filters and changed the oil, oil filter and fuel filters every 6-7,000 miles. My Baronet also had grease packed front wheel bearings not oil bath and I had those repacked at around 100,000 miles and it needed it. Hope you enjoy your Contessa.
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Thanks for all the advice, after a long day on the road we reached our destination. The coach ran smooth, only heated up the transmission a bit on a long slow uphill portion. Temp reached about 210 degrees. The one question I have is slowing the rig down on steep inclines. I dont have engine braking, felt like I had to put quite a bit of work on the brakes. I have the Allison 4 speed automatic. The manual said to keep the transmission in drive as down shifting would over speed the rpms. Any thoughts? Have to figure out a small windshield leak on right side. Had it resealed, and resealed all clearance lights, spotlight and horns. Any ideas? Used Dicor to seal around lights etc. Thanks
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Jason,
Use the tranny to keep the speed under control on downgrades. Brake enough to get speed down at top of grade, then down shift tranny to lower gears and let it hold your speed down. My research shows that 2700 RPM is max recommended by CAT for the 3116. That should be adequate for holding you back on steep/long inclines if you manage speed going into incline
Steve
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As per Steve you have to use the shifting down and getting slowed down before you begin the descent. If you want to test your brakes try ALT 14 over the Bighorn Mountains in Wyoming. We did and even though they have billboard size signs warning you it is still very easy to get into trouble down this long continuing descent as it never levels out. We used the next to last run off ramp to stop at and let em cool down. Never got into the stones off the asphalt apron but used it all to get stopped.....
With that in mind you might do as we decided to do after our brake smoking adventure and that is take off the towed and drive it down these long descents. The coach handles itself very well but that added push even though you have braking on it does not help enough without an engine brake. Your drum brakes, even if you get them turned and back into spec with new pads, will glaze under these type conditions and that you do not want as even though the drums are very stout they can also warp.
A little advice if you ever blow a rear tire - have the tire shop check your air lines before they put the tire back on. The air compressor will keep up with a badly severed air line when traveling but it will not keep up the air needed when you are using the brakes on a continued on off basis basis going down a long continuing grade. When the brakes started feeling soft, which air brakes should never do, is why I looked for a run off ramp as we still had over 10 miles to the bottom of the descent. The blown rear dual had mostly severed the right brake line during blowout near Omaha, NE on way to Wyoming.
After getting all cooled down and towed unhooked we continued down and at next and last run off ramp which was down mountainside due to mountain slope only going down then there is the 1970 vintage 35' motorhome with car on trailer being towed 7/8's of the way into the stone run off ramp buried to the skirts. I cant even imagine what that tow bill would be - more than the whole rig was worth I am sure. Had they gone another 100' there was a massive boulder to stop them from going out into the road that curved past the end of the runoff ramp.
HEED the signs with or without an engine brake.
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Our Baronet didn’t have an exhaust brake, I would downshift at the top of a mountain to 3rd sometime 2nd, usually the gear I went up the mountain in, when I got to 2400 rpm I would brake hard and slow to about 16-1700 rpm and then let it gain speed and brake hard again. That allowed the brakes to cool a little and air pressure to build. Make sure the brakes are adjusted properly. Hope this helps.
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With regard to using engine brakes, do you shift down before engaging them or engage them and shift down if you need to go slower?
MJ
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Michael, the term exhaust brake and compression brake have two different meanings as
correct operation of each. Let’s go with the exhaust brake is only effective for braking
at 45 mph or slower, the reason for this the engine exhaust pressure will over ride the
exhaust brake flapper an keep it open until rpms slow down engine. With the compression
brake operation is off the engine valve train and is more involved operation but has positive
braking action slowing engine down . The word of caution do not engage compression brake
with engine rpms higher than 1800 rpms, higher engine rpms can result in valve train damage.
Dave Atherton Retired Cat Mechanic
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Thanks Dave. Yes, I was talking about using the Engine Brake switch. If I understand you correctly, I should slow to 45 by braking or downshifting before engaging the engine brake. I was worried that once the engine brake is engaged if I need to slow more that downshifting again might put the RPM too high.
MJ
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Michael, what I explained the mixed thoughts between engine exhaust brakes and engine
compression brakes operations. I take it you have a Caterpillar C-12 and your engine has
What is called a compression brake that works off the valve train, what this will tell you
should not turn on or engage your engine brake until your engine rpms at 1800. Again with your
setup brake engagement at a higher than 1800 rpm damage can happen with engine valve
Train. Hope this helps you. Dave Atherton Retired Cat Mechanic
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Thanks Dave. Yes, I was talking about using the Engine Brake switch. If I understand you correctly, I should slow to 45 by braking or downshifting before engaging the engine brake. I was worried that once the engine brake is engaged if I need to slow more that downshifting again might put the RPM too high.
MJ
Michael, I believe Dave was referring to an exhaust brake. If I'm not mistaken you have a Jake Brake the same as my coach with C-12 does. The Jake is an engine brake and can be used at faster speeds. 2100 is about max RPM no matter the road speed. I use mine constantly but watch RPMs.
Jerry
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Could be Jerry. We have the same year of coach. I've refrained from venturing too far in my coach as I don't have to go too far before I start getting into the mountain and some long steep grades. I remember seeing some of the crashes they showed on my air brakes course when the air brakes are used improperly and the drum heats up and moves away from the pads. I decided to ask as I rather know before starting down a grade and the last thing out of my mouth is "oh mess!" Now that I know the key is the RPM limit governs when to use the Engine Brake switch I should be ok. I hope.
MJ
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Michael,
There are several variables that you need to answer before I can give you a definitive answer to your question. If your transmission has never been reprogramed to default to a different gear upon activation of your engine Jake Brake (compression brake), it will downshift to 4th gear when the you turn on the Jake if it can do so and keep the engine RPMs below about 2500. So you will need to slow to a speed that will keep the engine at your desired RMPs when the transmission is in 4th gear. However if the transmission has been reprogramed to a higher gear, you only need to slow to the speed that you are comfortable with since the transmission will not downshift and possibly result in engine RPMs that are above your comfort zone.
The normally considered correct procedure for descending a hill is to slow to the speed that you climbed the steepest part and shift to the gear that you used to climb that part. However, this does not always work because some hills have a slight grade on one side and a steep grade on the other side, so watch closely for road signs that indicate the approaching grade and slow down to a comfortable speed before starting down, and if in doubt, it is always better to be going a little slower than necessary. Remember, when going down hill, it is easy to speed up but difficult to slow down.
Gerald
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Thanks Gerald. I'll have to do a test run to see what gear it goes to or stays in when I apply the Jake brake. On the route I'm thinking of taking has an 8% downgrade for 2 miles. Will the Jake brake maintain a steady speed or will it gradually pickup speed?
MJ
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Could be Jerry. We have the same year of coach. I've refrained from venturing too far in my coach as I don't have to go too far before I start getting into the mountain and some long steep grades. I remember seeing some of the crashes they showed on my air brakes course when the air brakes are used improperly and the drum heats up and moves away from the pads. I decided to ask as I rather know before starting down a grade and the last thing out of my mouth is "oh mess!" Now that I know the key is the RPM limit governs when to use the Engine Brake switch I should be ok. I hope.
MJ
Dave apparently answered again about the time I did. I've been told the "red line" on a C-12 is 2300 RPM but only 2100 if a Jake is installed so thats why I quoted 2100 rpm. Dave just mentioned 1800 RPM for the Jake. It goes without saying that I would trust Dave with this one and stick with 1800 RPM. It confuses me because I'm told that our transmission will not let you over RPM the engine but it will easily go up to 2400+ when the Jake engages and downshifts to 4th. I pretty much turn mine off in the mountains because anything over 48 mph kicks the RPMs over 2100. Now I have to go even slower.
Good luck clearing the confusion.
Jerry
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Thanks Gerald. I'll have to do a test run to see what gear it goes to or stays in when I apply the Jake brake. On the route I'm thinking of taking has an 8% downgrade for 2 miles. Will the Jake brake maintain a steady speed or will it gradually pickup speed?
MJ
MJ, I frequently have to speed up going down steep grades. My Jake will keep me under 50 on about any steep grade I've run into to out West or on the way to Alaska and back. I don't use the brakes much. My problem is I tend to pass most traffic, even some cars on the way up and then get scared and slow way down when I hit the crest. Good luck.
Jerry
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Thanks very much Jerry.
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Michael and Jerry,
The redline on a over the highway C-12 is 2,100 RPMs under power. The marine version of the same engine has a redline of 2,300 RPMs. The issue here is what is the redline when descending a hill with the Jake brake on, and as much as I have researched this issue, I have never found the answer in any Caterpillar documents. I discussed this subject with an Allison engineer once and he told me that the deceleration redline that they had from Cat for their transmission programing purposes was 2,500 RPMs for RV use, but he did not have access to that Cat information at the time to show me. So at this time, everyone will just have to use the RPM redline that they are comfortable with when operating their coach.
Remember, if you try to research this issue yourself, there are 5 different common applications that the C-12 is used in with the marine, stationary (generators and pumps) and heavy equipment versions being the only ones still in production. The over the road engines that ended production in 2004 are broken down into 2 categories, trucks and RV/firetruck. The Truck engines deliver less horsepower and may have a tighter redline restrictions than the RV and firetruck version because the truck engine is expected to deliver over a 1,000,000 miles before overhaul, but the RV version rarely ever sees 1/3 to 1/5 of that. Therefore Cat is able to turn up the horsepower ratings, but no where near the water to water cooled marine version that can hit 700 HP.
Gerald
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So at this time, everyone will just have to use the RPM redline that they are comfortable with when operating their coach.
Gerald
Please Gerald, tell me what to be comfortable with! LOL just kidding kind of! There is a big difference between the 1800 RPM damage point Dave was mentioning and 2500 RPM deceleration RPM! I will have to get below 45 MPH to get down to 1800 RPM when the Jake slams it into 4th. I've never noticed it go to 2500 on the downhill but I have seen it at 2400+. Soon I will stop procrastinating and get the transmission reprogrammed. Thanks for your help!!
Jerry
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We had our C-12/Allison reprogrammed at the Kenworth shop in Pasco, WA. It took longer for the technician to round up his laptop and the correct connection wire than to perform the reprogramming. The whole process took about 20 minutes and we were off their lot. The technician had a road call just before completing the programming. He said he didn't have time to make up a bill - so no charge.
Now with the Jake on and in 6th gear, if I drop cruise control, then the Jake kicks on and it stays in 6th gear. No change in RPMs, therefore no slamming the engine to over 2,000 RPMs as it did before the reprogramming.
By the way, on our coach the programming connection plug was under the removable dash plate in front of the steering wheel.
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Gentleman little technical information that may be of interest. Compression Brake operations,
The compression brake should not be activated when engine rpm is above 1800 rpm. The
maximum power rating is 2100rpm. At this level, the amount of braking that is produced by the compression brake is aproimately 315 to 325 horsepower
Information Systems Operation: C-10 and C-12 Truck Engines Media Number-RENR2235-06
SMCS-1119, 1129
Dave Atherton Retired Cat Mechanic
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Gentleman little technical information that may be of interest. Compression Brake operations,
The compression brake should not be activated when engine rpm is above 1800 rpm. The
maximum power rating is 2100rpm. At this level, the amount of braking that is produced by the compression brake is aproimately 315 to 325 horsepower
Information Systems Operation: C-10 and C-12 Truck Engines Media Number-RENR2235-06
SMCS-1119, 1129
Dave Atherton Retired Cat Mechanic
So Dave, why do they program the Jake to come on at any RPM? Also why would they program it to slam the engine into 4th gear and 2400RPM? Could it be a difference like Gerald was saying in the engine application ie, truck vs. RV? It just boggles my mind that they say the Allison is programmed so it will not damage your engine by shifting inappropriately. I know on a car with auto transmission you can be going 60 and drop it into low. It won't shift until it's safe for the engine to do so. Why would Allison/Beaver do it differently? I don't doubt that the 1800 you quote is the limit but why would they do it differently? Thanks
Jerry
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I wonder if Dave meant to say "the compression brake shouldn't be activated under 1800 rpm".
The more rpm, the more braking (up to the engine's rpm limit).
From my Owner's Manual:
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Mike, that is correct an reading what you posted says the same on compression brake from
builder of compression brake. Reading again it seems the 2100 rpm and down to 1700 rpms.
What I posted off Caterpillar Service technical information they are saying 2100 rpms down
to 1800 rpm. Again everyone has different thoughts as how his motorhome should operate
and yes there is information from both the engine builder and builder of the Jake Brake.
Dave Atherton Retired Cat Mechanicq
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Jerry, yes you have a very good question. there seems to be Lot of mix thoughts on what is
a RV engine and a truck engine, than there is the off road heavy equipment engines. Will
answer your question so, every Caterpillar engine engine is assigned a serial number and
A arrangement number. In looking for information or parts for that serial number a person
in many cases will find the engine serial number that pertains to 40 engines that is used in
Trucks, R.V., off road heavy heavy equipment that use the same parts. The answer to your
Question Jerry, Caterpillar set a standard as how they want there engine specs set for trouble
free operations. Other company’s like Allison transmission have there own thoughts where
Specs should be set for there product. The jakebrake builder as you can see on post bove this
Specs run nearly the same s Caterpillar, which would tell, person maybe there is something
I may overlooked. Now going back to Allison transmission builder they also have there own ideas
about how high engine rpms will operate within there transmission range. Myself being a
Caterpillar person understanding there engines would go with the technical values on operation
Of there engine as posted when to enguge the compression brake
Dave Atherton Retired Cat Mechanic