Community Forums

Alibamafan · 01-03-2016, 07:28 PM

on 2008 Phaeton can someone tell me where the air compressor is located? Book says in the front, someone told me it is beside the generator. I haven't located it.

dpinvidic · 01-03-2016, 08:05 PM

What model Phaeton?

If your talking about the air brake compressor, they are mounted to the diesel engine.

Regards,

Dan

luvlabs · 01-04-2016, 07:20 AM

If you want to access the compressed air fitting to use the engine compressor to fill your tires, that fitting is in the front compartment under the driver.

The compressor itself, as Dan said, is mounted on the engine.

DeWat · 01-04-2016, 11:51 AM

I might be wrong on this, and if not wrong, I don't know when the change occurred... BUT... I thought the air tap was located near the generator in early model years prior to be moved to the first DS basement bay. I only mention this since the OP has a 2008.

kb9tf · 01-04-2016, 01:01 PM

My 2008 is also in the left front compartment with the electrical stuff.

Alibamafan · 01-04-2016, 06:40 PM

I had found the air tap in the left front compartment but was only able to get 80 pounds of pressure from that tap. I was attempting to locate the compressor for this air tap to check if there was some blockage causing the lose of pressure.

Alibamafan · 01-04-2016, 06:47 PM

thanks for the info. I will check engine for compressor.

luvlabs · 01-05-2016, 07:28 AM

80 psi sounds like either the engine was off or the system wasn't calling for more air. The normal high cutoff for the air system, when the engine is running, is 120 psi. You need to construct an air tap system that allows you to drop the pressure below 80 psi to trigger the compressor to start. The system will then go until the high limit (120 psi) is reached.

rver98 · 01-05-2016, 08:35 PM

Quote:

Originally Posted by luvlabs

80 psi sounds like either the engine was off or the system wasn't calling for more air. The normal high cutoff for the air system, when the engine is running, is 120 psi. You need to construct an air tap system that allows you to drop the pressure below 80 psi to trigger the compressor to start. The system will then go until the high limit (120 psi) is reached.

X2!

I also use this technique with my portable air compressor.

Alibamafan · 01-05-2016, 09:39 PM

Rainy day so I did not check compressor but will lower pressure next time and see if that will cause compressor to raise pressure. Thanks for the info you have been great. I am not new to a motorhome just new to a diesel.

dpinvidic · 01-06-2016, 10:22 AM

Quote:

Originally Posted by Alibamafan

Rainy day so I did not check compressor but will lower pressure next time and see if that will cause compressor to raise pressure. Thanks for the info you have been great. I am not new to a motorhome just new to a diesel.

Just to be clear on this, the compressor actually runs all the time.
There is a regulator (bypass) which limits the pressure to 120PSI.
If you have a home compressor, you are somewhat familiar with this in that the compressor runs until it reaches a max limit and shuts off.
It will not turn back on until the pressure drops 30psi or so.

Same for your coach. So the gauges can read anywhere from 90psi -120psi. The bypass will release and allow air to enter the tanks when it sees about 90psi. You will here the famous "burp" when the tanks reach 120PSI.

So your goal is to only inflate the tires when the tank pressure is higher than the tire pressure. That is why you need to bleed off air to get the compressor to kick in and bring the pressure back up. As soon as you see the tank PSI is higher than your tire, start inflating...the compressor will keep pumping.

Hope this helps.

Regards,

Dan

firedoc · 01-06-2016, 11:33 AM

For whatever it's worth here is a picture of a McGyver device I made(after seeing it on this forum). One gauge reads the tire pressure and one gauge reads the pressure in the compresser tank. The valve is used to decrease pressure in tank until compressor is triggered to run. I attach it to a Porter Cable unit in one of my storage compartments rather than to the access port to the mh air as I don't want to have to start up the motor home and idle it every time I need air.

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Alibamafan · 01-06-2016, 08:45 PM

Thanks, the info has been very helpful. Releasing the pressure to activate the compressor works fine.

billdreamlv · 07-27-2016, 06:06 PM

Remember that the air pressure keep the brakes from contacting the drums while you are rolling down the road. BUT, if you lose pressure and the pressure goes below 42 pounds, the brakes will lock up where ever you are. So, if you lose pressure you should immediately pull off the road because it won't be long before you will be in a full skid.