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Gatorbite76

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Jun 18, 2021
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Alexandria, Louisiana
Ive worked at an rv repair shop over a year now, and I’m finally facing an air brake issue. It’s in a fleetwood providence. I hate to say I’m in uncharted territory… but I am. I have the customer ready to get his rig back, a boss on my tail like I’m an air brake specialist- any help would be so greatly appreciated. I only want to do the highest quality repair possible, or as best as I can
 

Lou Schneider

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Mar 14, 2005
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Welcome to The RV Forum! I'm not an air brake specialist either, but I'd suspect the air compressor is seizing up and stalling the engine.
 

Matt_C

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Mar 4, 2019
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SE - Mich
Gator,
Lou has at least a good starting point.
There are (used to be) two kinds of compressors.
The kind that have an unloader. The makes the compressor not able to pump when set point is reached.
The kind with a clutch like an A/C compressor uses to disconnect the compressor when not needed.
This kind may have a control system that looks for pressure when there is demand (like stepping on the brake peddle). So, I would start by looking for a compressor problem.
Matt
 

Gary RV_Wizard

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A Fleetwood Providence has a Freightliner XC chassis and a pretty much standard truck air brake system. The engine driven air compressor builds pressure in the air tanks and the brake treadle valve releases that pressure into the brake lines as needed to move the disc brake calipers for braking. You might want to call Freightliner Custom Chassis and ask what can cause that sort of issue. 1-800-FTL-HELP (have the chassis VIN handy).

The only way the compressor can stall the engine is if it fails to manage pressure properly or fails to disengage from the engine once working pressure is achieved. Some likely things to check first would be a clogged air dryer dessicant cartridge (too many owners never change those) or that unloader or clutch mentioned in a previous message.
 

Mark_K5LXP

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Albuquerque, NM
Not to sound cold, but the last person I want working on my brakes is someone that has to post to a public forum asking what to do. Being in the trenches of field service myself in another life my response to when I was handed something out of my league was "pass". There's no way they're paying you so much that you are obligated to do something you're not skilled, or qualified to do. This is also a huge liability for the shop, sending someone out on the road on brakes patched up on internet advice. Imagine if you were the customer and the guy fixing your rig is using you for OJT. This is improper bordering on negligent.

Mark B.
Albuquerque, NM
 

ChasA

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Mar 21, 2009
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I agree with Mark. Air brakes are something you should not be messing with and need training for. If you go messing with the cans on the rear brakes you could get seriously injured.
 

Gary RV_Wizard

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Air brakes are something you should not be messing with and need training for

There certainly are parts an amateur shouldn't mess with, at least not without some guidance, but much of an air brake system is just a compressor and lots of plumbing. Do you need a powertrain engineering degree to change the engine oil? Or electrical technician training to diagnose & repair a dead battery?

That said, Gatorbite76 didn't even claim any chassis mechanical experience, let alone vehicle air systems. Just that he worked in an RV shop for a year. Not much of a resume' for this kind of diagnostic task. He should decline.
 

Matt_C

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Gator,
I disagree with Mark here in a very serious way.
The problem you are dealing with is not the brakes directly, but it is the air compressor. If you can diagnose the issue effectively and get the compressor to work correctly, then test the brake function in a safe manor, then you have done all that the owner needs.
Now, if the brake pedal stops stalling the engine but the system pressure does not get into the green, now there is a serious issue that has to be addressed.
Matt
 

Mark_K5LXP

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Albuquerque, NM
The distinction I make here is personal vs professional. It's one thing when you have DIY owners here that discuss fixing things and engage in working on their own stuff. I work on all my own things and understand that no matter what anyone tells me, it's up to me to effect the correct repairs and my own risk if I screw it up. In this case we have an owner that's paying for professional services and likely has an expectation there is competency that it will be done correctly. When you go to a doctor or a dentist, hire a plumber or any other professional service you don't expect to have to train them first, or hope that they don't screw it up. Maybe I'm reading too much into the initial post but if I take my equipment to a repair facility my expectation is that the guy working on it has some idea what to do that justifies the money they're charging. Something tells me there aren't too many folks here that would be happy with the idea of dropping off their RV for brake service then seeing a post from the shop on a forum about their rig asking what they should do.

Mark B.
Albuquerque, NM
 

Edd505

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Mar 22, 2021
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Elephant Butte, NM
My first question is do you even know how to do a proper air brake test? Pressure required for alarms and setting of the failed brakes? Lives depend on brakes working, drop off Donner pass or Cabbage in OR w/o brakes. 80,000 down on Cabbage 18MPH
 

Gary RV_Wizard

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I think this discussion has gone far afield. The reported problem here is that pressing the brake pedal stalls the engine, not that the brakes don't stop the coach. A brake function test is perhaps advisable once the problem is fixed, but the upfront issue is an air compressor and air supply problem and not explicitly the air brakes. Still, it ought to be diagnosed by someone with at least a basic working knowledge of vehicle air systems.
 

Edd505

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Mar 22, 2021
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Elephant Butte, NM
I think this discussion has gone far afield. The reported problem here is that pressing the brake pedal stalls the engine, not that the brakes don't stop the coach. A brake function test is perhaps advisable once the problem is fixed, but the upfront issue is an air compressor and air supply problem and not explicitly the air brakes. Still, it ought to be diagnosed by someone with at least a basic working knowledge of vehicle air systems.
If he doesn't know the basic brake test someone else needs to work on the air brakes, exactly my point. Don't know basic leave it alone.
 
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