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Topic: Broke down (Read 3580 times) previous topic - next topic

Re: Broke down

Reply #40 –
Quote from: Cpt_kludge –
Never had air brakes except on our Fire truck!

If losing excessive amount of air when brakes are being applied you have an air leak in a valve, brake line or brake can. To check chock wheels have full tank of air and engine off disengage emergency brake and apply steady pressure to the brake pedal watch for a continual drop in air pressure and have someone walk around and listen for air leaks. If so you're out of service, repair before travel.

Re: Broke down

Reply #41 –
Looking at the video, when you apply the brakes, are your RPMs really fluctuating that much? You can hear your engine RPMs bounce like that? If not,  it could be a gauge/ground issue.

Second what Brett said, do a brake test, I don't have the link but there is about 6-7 tests to do.

Re: Broke down

Reply #42 –
Wolfe,
 It's what?  60 lbs before the brakes lock up?

Re: Broke down

Reply #44 –
Quote from: Cpt_kludge –
Do you mean release?



Yes to both.  When PSI descends below 60 PSI, the parking/emergency brake applies (most around 45 PSI).

Above that, the parking/emergency brake can be released.

Re: Broke down

Reply #45 –
Quote from: Jason –
Looking at the video, when you apply the brakes, are your RPMs really fluctuating that much? You can hear your engine RPMs bounce like that? If not,  it could be a gauge/ground issue.

Second what Brett said, do a brake test, I don't have the link but there is about 6-7 tests to do.
Yes, as soon as you step on the brake, the RPM'S go to normal Idle.

Re: Broke down

Reply #46 –
When our cruise was stuck at WOT, stepping on the brakes also dropped the throttle to low idle.

Re: Broke down

Reply #47 –
Quote from: Dave Larsen –
When our cruise was stuck at WOT, stepping on the brakes also dropped the throttle to low idle.
Less that WOT for me. That is about 2600 RPM. Guy at Foretravel thought it was a reaction to overheat. did NOT tell me how to tun it off :(

Re: Broke down

Reply #49 –
Quote from: wolfe10 –

Yes to both.  When PSI descends below 60 PSI, the parking/emergency brake applies (most around 45 PSI).

Above that, the parking/emergency brake can be released.
So,  hes dangerously close to having his brakes lock up if he were moving in that video?

Re: Broke down

Reply #51 –
Quote from: Moby –
So,  hes dangerously close to having his brakes lock up if he were moving in that video?
So spring brakes don't lock up. They apply there full force but is less than fully applied brake. Many variables with different brakes and weights, but on my coach if you set the parking brakes you will come to s safe controlled stop using only the rear brakes as they are only installed on the rear.

Re: Broke down

Reply #52 –
Quote from: Cpt_kludge –
Looking for the whistling after shutdown.
Lift up the bed platform.  Look around your engine compartment walls.  If you see anything that looks like the photo below then that is the Bendix cruise control setup.  See if the "whistling sound" is coming from any of the components on that plate.  If it is, that component might be the source of your high idle problem.  Let us know what you find.


Re: Broke down

Reply #54 –
When the parking brake is applied or the pressure drops below 45 psi or so,  it will apply but the spring in the can cannot come anywhere near the air pressure your brake pedal applies when you step on the brakes. That's why the parking brake should only be used on flat ground and with even a slight slope, chocks should be placed in front and behind a wheel.

To check the effectiveness of the parking brake, apply it at about 30 mph and you will be surprised by the distance it takes to stop the coach.

If the service brakes are heated on a downgrade to the point of losing effectiveness, applying the parking brake will do absolutely nothing so should never be considered as any kind of safety resort. I overheated the brakes on  (at 10 mph) a steep mountain road above Malibu, CA in first gear! Applying the Anchor Lok/parking brake did nothing and I had to put the right side wheels of the fire truck down into the dirt shoulder to get it to stop.This is what happens when a city is too cheap to put a Jake brake on the truck but still sends it to fight campaign/out of town fires.

Pierce

Re: Broke down

Reply #55 –
Quote from: Cpt_kludge –
Less that WOT for me. That is about 2600 RPM. Guy at Foretravel thought it was a reaction to overheat. did NOT tell me how to tun it off :(

As BW said in reply #31, the 3116 is not computer controlled.  The guy at FOT was just mistaken. 

Re: Broke down

Reply #56 –
If you happen to be headed north, Mark at MC Diesel in Albuquerque is a great Cat mechanic.  He might be willing to work on the throttle/cruise issue. If you do go there, have him adjust your injectors and valves.
M.C. Diesel | Albuquerque Diesel Mechanic |

Re: Broke down

Reply #57 –

Wagner is the Caterpillar dealer right there in Las Cruces.

No nothing about them, but they could certainly get you a new thermostat (Cat calls them regulators) and gasket.  Just need your engine serial number.

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Re: Broke down

Reply #58 –
I'm back.
Looks like the 2100RPM and whistling is definitely the Bendix. Cannot see where the sound is coming or feel any blow by but it all corresponds to 78lb of pressure. When you shut down, the whistle persists till about 60lb and after you start, starts at 78lb where it pulls on the cable. Posting videos (smaller).
All videos are here!
https://www.dropbox.com/s/wz7c5zktkq1z7gk/20220704_155309_1.mp4?dl=0
https://www.dropbox.com/s/j3brhzzrucf16qz/20220704_155548_1.mp4?dl=0
https://www.dropbox.com/s/mn89ufhruta1f0z/20220703_115507.mp4?dl=0

Re: Broke down

Reply #59 –
Wonder if the RV-1 Reducing Valve is bad and the bendix is getting way over pressured?

What did you find when you opened the tank drains?