Jump to content
rudischaffner

exhaust brake

Recommended Posts

I'll ask Linda if mine are on!  I would prefer a blinking rear light.  On steep long grades up/down I put on my emergency lights!

Share this post


Link to post
Share on other sites

My MH has an exhaust brake, the brake lights illuminate when the exhaust brake engages, which is my preference anyway. Most OTR truckers will turn on their 4-ways if their brake lights do not illuminate with the engine brake - when they are below 45 MPH. BTW, that is the only time 4-ways are legal while driving on interstates.

 

Share this post


Link to post
Share on other sites

Yea.  Minimum speed limits on most/if not all Interstates is 45 mph!  Tell that to the PR farmer in Florida, they'll come on I-75, cross over to left lane and do a crawl..:wacko:

Share this post


Link to post
Share on other sites

I would rather have it on.  However, when in hilly country I have to stop every couple hours and run the TOAD engine to keep the battery charged up.  Learned the hard way on both a 2007 Saturn and now the 2013 Lincoln. If you don't stop and run, battery will go below starting capacity.

Yep, going to install a charge line one of these days.

I need to stop and stretch the legs anyhow.

Share this post


Link to post
Share on other sites
11 hours ago, wayne77590 said:

I would rather have it on.  However, when in hilly country I have to stop every couple hours and run the TOAD engine to keep the battery charged up.  Learned the hard way on both a 2007 Saturn and now the 2013 Lincoln. If you don't stop and run, battery will go below starting capacity.

Yep, going to install a charge line one of these days.

I need to stop and stretch the legs anyhow.

I don't know if this would work on your Lincoln, but I had the same problem with both my Honda CRVs.  Solved it by installing a bigger battery with more reserve power.  A Honda Odyssey  battery fits the CRV, a little tight, but works okay, no problems since.

Share this post


Link to post
Share on other sites

Yes, I would add a good charge line:

Fuse at coach battery (which ever battery bank is closer to the back of the coach). Since this will be used while driving, the alternator will charge both banks so it is not critical whether you use chassis or house battery. Sized to protect whatever size wire you use. 

8 Gauge wire recommended, fuse to back of coach.

Water proof connection at back of coach/front of cord to toad.

8 Gauge wire to fuse at toad battery.  This fuse is also critical, as both coach end and toad end batteries are "hot".

Note:  the ground between coach and toad will also have to be of sufficient gauge.

Share this post


Link to post
Share on other sites

Five, sounds good. Next time I need a battery I'm going to ask for one with more AH's.

Brett, Yep on all of that. I'm going to purchase on that already has all the wiring. Any suggestions?

Share this post


Link to post
Share on other sites
On ‎12‎/‎1‎/‎2019 at 2:02 PM, jleamont said:

Rudi, let it shift on its own. The only thing I do is monitor engine RPM’s, if they climb too high I step on the brake to keep it in a safe range (Stab brake technique). 

Sometimes it gets a bit too close to redline for my likings.

Clarify "stab brake technique" for me please.  I'm new to air brakes, and read in an owner's manual that I should not pump the brakes due to the risk of depleting air pressure.   I've always been a brake-pumper with hydraulics. 

Share this post


Link to post
Share on other sites
47 minutes ago, UrbanHermit said:

Clarify "stab brake technique" for me please.  I'm new to air brakes, and read in an owner's manual that I should not pump the brakes due to the risk of depleting air pressure.   I've always been a brake-pumper with hydraulics. 

I just posted on a similar question. Read it and let me know if you have any questions.

https://community.fmca.com/topic/15762-steep-hills-pac-brake/

Bill

Share this post


Link to post
Share on other sites

Apply the service brakes hard, not enough to engage the ABS for 1-2 seconds, watch the speedometer and tachometer drop , let off.

The last thing you want to do is ride the brakes, they will overheat quickly and fail especially if they are drum brakes. 

Share this post


Link to post
Share on other sites

You create the same amount of heat to slow down no matter  hard or soft 

Use your gears and try  to use the brakes less 

Be safe 

Share this post


Link to post
Share on other sites

The idea of using your brakes firmly is to pretty quickly get your speed down to where you can shift to a lower gear where you will have more braking HP from the engine/exhaust brake.

If you have to use your brake pedal more than very infrequently, you are in too high a gear/going too fast.

Physics dictates that your "equilibrium speed" (neither slowing down nor speeding up) on a downgrade will be faster than a loaded 18 wheeler, slower than an empty one.

Share this post


Link to post
Share on other sites

Yep! Keep speed down to engage lower gear.  Typically exhaust brakes are set to downshift to 2nd gear. The Allyson transmission will not go directly to that gear if the speed is up but will downshift to the next lowest gear depending on your speed. As you are descending a hill the momentum will cause you to speed up. Let's say the speed limit is 65 and as you go down the hill you are up to 70 or 72. Apply the brakes, slow down to 60 or so and let the exhaust brake work for you. as it speeds up repeat the process.  I know when the momentum will speed up the vehicle so I apply my brakes to slow down to about 10 or so mph under the limit and as it speeds up I repeat the process.  Many times you know the hill exists so downshifting when you get to the top and start down is always good.  I have found that typically 4th gear is good but I have even gone down to 2nd gear on some grades.  Yep, slows you down to 20-25 and people will fly by you but that is better than heating the brakes up and have them fail.  Happened to my FIL once and he had to exit a run-away landing. He said it wasn't fun.

Share this post


Link to post
Share on other sites

Do NOT be overly concerned about going slower than car traffic.  Again, the loaded 18 wheelers will be going even slower.

To be at your proper "equilibrium speed", you will NOT be the slowest vehicle on the road!

You are driving a heavy vehicle, not a car!

 

Share this post


Link to post
Share on other sites
6 hours ago, jleamont said:

Apply the service brakes hard, not enough to engage the ABS for 1-2 seconds, watch the speedometer and tachometer drop , let off.

The last thing you want to do is ride the brakes, they will overheat quickly and fail especially if they are drum brakes. 

Exactly! If the engine RPM's reach red-line(ISC is 3200RPM) for engine braking, the ECM and TCM WILL command a transmission upshift to protect the engine. That leaves the driver with only the service brakes for downhill control until the driver can use the service brakes to bring speed down enough for the ECM/TCM to allow a downshift to a lower gear, where the exhaust brake once again is effective.

Share this post


Link to post
Share on other sites
1 hour ago, RayIN said:

the ECM and TCM WILL command a transmission upshift to protect the engine

Interesting you brought this up. Mine was set to "Disable" for my engine over rev protection" in my ECM settings. Three weeks ago I changed a bunch of engine parameters, that was one of them I flipped to "Enable". I have over revved my engine with the brake on "HIGH" , I have learned, over 54 mph if I engage the engine brake it will over rev. Using the brake technique above quickly gets it under control I usually step on the brake at the same time I flip the switch at or above those speeds. the trip home from work with it I didn't get a chance to give it a try, speeds were too low. My cruise control now works properly so that one big plus!

My coach left the plant on Saturday July 7 2001. The running joke is never purchase a car built before a holiday or on a Monday or Friday. Saturday brought an entirely new level to that statement. Most of my ECM settings made no sense, like someone was in a hurry to go home. My compression brake only ever worked on HIGH, the HIGH/LOW switch did nothing, turns out it was set to "exhaust brake" in the settings, now its set to "Compression" my high/low switch now works. 

Off subject, I did figure out my engine left Cummins as a 425HP and was derated by HR/Monaco to 395 (supposed to be 400, remember the Saturday thing above :wacko:). Its now a 425 again, that setting was available at no cost, usually there is an up charge which leads me to believe it left Cummins as a 425. Since I have EGT and electronic temperature monitoring I can see if the coach coolant package can handle the change and the transmission is already rated to 450HP. 30HP isn't anything to write home about but you can feel it pull harder. 

Share this post


Link to post
Share on other sites

In the old days when we only used manual transmissions, driving instructors taught to go down a grade in the same gear that was necessary to climb the grade, and we used the stab brake technique back then to keep from over revving the engine.

Share this post


Link to post
Share on other sites
4 minutes ago, kaypsmith said:

stab brake technique

I was taught that when I got my CDL....long time ago, the instructor pounded it into me. When I trained mechanics for their CDL we practiced it. You ride too long with your foot on the service brake you in trouble! The mechanics understood and could connect the dots with the brake damage they come across often. 

Share this post


Link to post
Share on other sites
2 hours ago, jleamont said:

Interesting you brought this up. Mine was set to "Disable" for my engine over rev protection" in my ECM settings. Three weeks ago I changed a bunch of engine parameters, that was one of them I flipped to "Enable". I have over revved my engine with the brake on "HIGH" , I have learned, over 54 mph if I engage the engine brake it will over rev. Using the brake technique above quickly gets it under control I usually step on the brake at the same time I flip the switch at or above those speeds. the trip home from work with it I didn't get a chance to give it a try, speeds were too low. My cruise control now works properly so that one big plus!

My coach left the plant on Saturday July 7 2001. The running joke is never purchase a car built before a holiday or on a Monday or Friday. Saturday brought an entirely new level to that statement. Most of my ECM settings made no sense, like someone was in a hurry to go home. My compression brake only ever worked on HIGH, the HIGH/LOW switch did nothing, turns out it was set to "exhaust brake" in the settings, now its set to "Compression" my high/low switch now works. 

Off subject, I did figure out my engine left Cummins as a 425HP and was derated by HR/Monaco to 395 (supposed to be 400, remember the Saturday thing above :wacko:). Its now a 425 again, that setting was available at no cost, usually there is an up charge which leads me to believe it left Cummins as a 425. Since I have EGT and electronic temperature monitoring I can see if the coach coolant package can handle the change and the transmission is already rated to 450HP. 30HP isn't anything to write home about but you can feel it pull harder. 

Gee, that sounds like the ECM went directly from box to installed, bypassed setup and QC

Share this post


Link to post
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now

×
×
  • Create New...