Air blowoff sound every 2-4 seconds?

Topic: Air blowoff sound every 2-4 seconds? (Read 1601 times) previous topic - next topic

Re: Air blowoff sound every 2-4 seconds?

Reply #25 – April 15, 2023, 11:24:01 am

Quote from: nebster – April 13, 2023, 04:05:32 pm

Thanks, all. There is none of the recurring blowing-off sound when the coach is sitting still, at idle or otherwise.
I wondered, too, if it might be the height valve just being sensitive. But I have had these on other coaches and not really noticed them making so much sound constantly. Maybe mine is just doing its thing, but a little noisily. I'll look the possibility of a missing HCV muffler! I like the idea that this is the problem, because it sounds relatively unimportant and also easy to fix. Hehehe.

You could pull the 7.5 amp travel mode fuse in HWH control box at proper ride height and take for test run, that would take the ride height valves out of the scenario.

Also would check to see if ride height valves are in neutral position at ride height. Meaning the horizonal rod being at 3:00 or 9:00 position, left and right valve. If not the valve is going to react faster to any uneven road surface.

Setting Ride Height Control Valve for Neutral Position

Re: Air blowoff sound every 2-4 seconds?

Reply #26 – July 03, 2023, 12:35:13 pm

Just to circle back on this: I've been able to confirm that the problem is not a faulty ride height valve.

More to the point, the blow-off sound is correlated with increasing the engine power. Push the accelerator peddle? More blow-off, more frequently. Coast up to a stoplight? Not much at all. Idle at the light? No blowing off sound.

I'm assuming I need to swap out a bad D2 governor at this point. That's where we'll start, at least, when we finally get this gal into the shop for an accumulating list of squawks to work out.

Re: Air blowoff sound every 2-4 seconds?

Reply #27 – July 03, 2023, 01:47:46 pm

My bet is on Air dryer check valve.

Re: Air blowoff sound every 2-4 seconds?

Reply #28 – July 03, 2023, 02:11:10 pm

When was the last time the air dryer was replaced or overhauled?

I would start there and consider it Preventive Maintenance if it hasn't been done in the last 3 years.

Least costly option to get a quality dryer is a factory (i.e. the factory that made it, not a "made to replace" one of dubious quality) REMAN unit. That will come with new filters, valves and heater.

Re: Air blowoff sound every 2-4 seconds?

Reply #29 – August 27, 2023, 04:27:55 pm

Brett, you are the winner.

We tried replacing the D2 governor first, since it's cheap and easy. But it turns out we needed a new dryer, after all. About $600 for the Bendix and the swap labor.

Re: Air blowoff sound every 2-4 seconds?

Reply #30 – August 27, 2023, 04:57:47 pm

Nebster,

You could do the dryer replacement yourself, and likely you only need a bottom maintenance kit, both could save $.

Re: Air blowoff sound every 2-4 seconds?

Reply #31 – August 27, 2023, 06:43:24 pm

Another very good option for an air dryer is a factory reman dryer. But the company that made it, NOT a cheap "made to replace" of dubious quality. That replaces the filters, valves and heaters. $600 is HIGH.

Re: Air blowoff sound every 2-4 seconds?

Reply #32 – August 27, 2023, 07:08:50 pm

Quote from: wolfe10 – August 27, 2023, 06:43:24 pm

Another very good option for an air dryer is a factory reman dryer. But the company that made it, NOT a cheap "made to replace" of dubious quality. That replaces the filters, valves and heaters. $600 is HIGH.

$600 High
New dryer and install, actually as much as everything has gone up it actually is probably about right. I still find myself spending my money thinking it holds the value it did ten years ago and just doesn't. 5$ burgers are 12$ now.

Re: Air blowoff sound every 2-4 seconds?

Reply #33 – August 27, 2023, 07:23:42 pm

Quote from: dsd – August 27, 2023, 07:08:50 pm

$600 High
New dryer and install, actually as much as everything has gone up it actually is probably about right. I still find myself spending my money thinking it holds the value it did ten years ago and just doesn't. 5$ burgers are 12$ now.

I just did a search for Reman Bendix AD-9. First hit was: Bendix Reman AD-9 Air Dryer ID: 109685BXR

$187.98 after return of usable core.

Re: Air blowoff sound every 2-4 seconds?

Reply #34 – August 27, 2023, 07:56:56 pm

Is that including labor also?

Re: Air blowoff sound every 2-4 seconds?

Reply #35 – August 27, 2023, 09:53:53 pm

Quote from: rbark – August 27, 2023, 07:56:56 pm

Is that including labor also?

If you are asking about my post-- no, parts place.

But, add one hour at $150 for labor.............

Re: Air blowoff sound every 2-4 seconds?

Reply #36 – August 28, 2023, 02:58:56 pm

probably NOT related but I had the same issue until I noticed my retarder was on and left in a position it was activating. The air was being released in "spurts" as it activated..
Peter

Re: Air blowoff sound every 2-4 seconds?

Reply #37 – August 28, 2023, 03:37:43 pm

Quote from: nebster – August 27, 2023, 04:27:55 pm

Brett, you are the winner.

We tried replacing the D2 governor first, since it's cheap and easy. But it turns out we needed a new dryer, after all.

Just to tie up a couple of loose ends - was it just the valve on the air dryer or was there evidence of a desiccant canister failure (white powder) or moisture where there shouldn't be (tank drains)?

Re: Air blowoff sound every 2-4 seconds?

Reply #38 – September 04, 2023, 03:49:08 am

Quote from: Michelle – August 28, 2023, 03:37:43 pm

Just to tie up a couple of loose ends - was it just the valve on the air dryer or was there evidence of a desiccant canister failure (white powder) or moisture where there shouldn't be (tank drains)?

Hmm, not quite sure, Michelle. I had this work done at a shop, and all they did was explain that, after the D2 governor was a no-go, "the only thing left in the system to replace is the air dryer." I don't think there was any meaningful moisture in the tanks, though; I know those drains were checked recently.

Re: Air blowoff sound every 2-4 seconds?

Reply #39 – September 04, 2023, 03:52:27 am

Quote from: Barry & Cindy – August 27, 2023, 04:57:47 pm

Nebster,

You could do the dryer replacement yourself, and likely you only need a bottom maintenance kit, both could save $.

Yeah, seems like something worth learning to do one day. Time is pretty short right now, though.

Re: Air blowoff sound every 2-4 seconds?

Reply #40 – September 04, 2023, 03:54:28 am

Quote from: wolfe10 – August 27, 2023, 06:43:24 pm

Another very good option for an air dryer is a factory reman dryer. But the company that made it, NOT a cheap "made to replace" of dubious quality. That replaces the filters, valves and heaters. $600 is HIGH.

Interestingly, they actually had to charge me for nearly two hours of labor. Apparently the (new, not reman) dryer needed to be "adapted" to be swapped in, both physically and electrically. Who knows what that means!

Re: Air blowoff sound every 2-4 seconds?

Reply #41 – September 04, 2023, 08:31:43 am

Quote from: nebster – September 04, 2023, 03:54:28 am

Apparently the (new, not reman) dryer needed to be "adapted" to be swapped in, both physically and electrically. Who knows what that means!

I do. It means they have to remove some large fittings from the old dryer and install them on the new dryer. The fittings must be pointed in the proper direction to make the new dryer fit. The fittings can sometimes be very difficult to remove from the old dryer (IE they are screwed in very tight). Also, some dryers have a 12V heating element on the purge valve. This element has a wiring connector which must be removed from the old dryer and attached to the wires on the new dryer. None of this work is rocket science, but it does take time. Having done the dryer swap on our coach myself several times, I can assure you that adding some additional labor time to the ticket for "adaptation" is not unreasonable...

What IS unreasonable is how much shops charge for the "labor rate" these days! It is legalized highway robbery!

Re: Air blowoff sound every 2-4 seconds?

Reply #42 – September 04, 2023, 08:32:09 am

Quote from: nebster – September 04, 2023, 03:54:28 am

Interestingly, they actually had to charge me for nearly two hours of labor. Apparently the (new, not reman) dryer needed to be "adapted" to be swapped in, both physically and electrically. Who knows what that means!

I know. I've done it. New fittings and possible a new hose or two.

Re: Air blowoff sound every 2-4 seconds?

Reply #43 – September 04, 2023, 10:03:40 am

Labor rate has gone to about 150 per hr for easy stuff and 450 for fancy. I sent a Maserati to a shop for an engine swap. The engine was 3000$ and the labor was 4000$.
For swapping the dryer. Take a pic before you remove anything and mark the hoses for their destination . Loosen the fitting before you unbolt it from the brackets .

Re: Air blowoff sound every 2-4 seconds?

Reply #44 – September 04, 2023, 11:15:55 am

Quote from: Protech Racing – September 04, 2023, 10:03:40 am

For swapping the dryer. Take a pic before you remove anything and mark the hoses for their destination . Loosen the fitting before you unbolt it from the brackets .

That is certainly one excellent way to proceed, IF your dryer setup allows adequate room to work.

On our coach, however, there is not sufficient open space around the dryer to allow easy removal of the "tight" fittings. I can't get a long enough wrench and/or a cheater in there to work. So I remove the old dryer (with all fittings still in place) and take it to my work bench. I already have the factory rebuilt dryer (from NAPA) sitting there ready to go. Using a big bench vise to hold the dryer, and suitable wrenches with cheater, I remove the fittings from the old dryer and transfer them to the new unit. Fresh rebuilt dryer goes back in the coach - old dryer core goes back to NAPA for a refund. Works for me!

Re: Air blowoff sound every 2-4 seconds?

Reply #45 – September 04, 2023, 04:23:39 pm

I agree with the consensus view that labor rates these days are eye-watering. :-)

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