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Brake Filter Air Leak ?

July 30, 2019, 07:56:45 pm

As a relatively new owner, maybe I just haven't heard it before.  Is it normal to have air releasing from the bottom of the Filter unit after shutting of the motor ?

Seems to last several minutes. It's coming from the bottom of this unit.

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Re: Brake Filter Air Leak ?

Reply #1 – July 30, 2019, 08:30:49 pm

Mark, that looks like the air dryer.  It shouldn't be venting air.

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Re: Brake Filter Air Leak ?

Reply #2 – July 30, 2019, 08:31:16 pm

There is a relief valve in the base of the filter housing, but I don't think you should hear it bleeding air after shutting down the coach.  Any idea when it was last serviced?

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Re: Brake Filter Air Leak ?

Reply #3 – July 30, 2019, 09:13:40 pm

It was supposed to have been service about a year ago. I have nothing to support that though.  It is bleeding the air from the bottom of the unit. A plastic part with a nipple type fitting coming off the bottom that also has a couple of wires running from it. Possibly a air heater, but not sure.

Thank you.

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Re: Brake Filter Air Leak ?

Reply #4 – July 30, 2019, 09:22:13 pm

This is a similar picture, the air is coming from the bottom of part #6

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Re: Brake Filter Air Leak ?

Reply #5 – July 30, 2019, 09:28:44 pm

Mark,

Sounds like the piston that is inside part #6 has either broken or is jammed.  At this point you will need to completely rebuild the unit.  If you don't have the proper place to do a rebuild then it will be better (and sometimes cheaper) to just get a factory remanufactured one.

Mike

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Re: Brake Filter Air Leak ?

Reply #6 – July 30, 2019, 09:37:35 pm

Two kits are required to completly overhaul a haldex air dryer. Replace the Dessicant yearly.
I replace the lower kit every couple of years. The lower kit contains the fix for your issue. There's a shuttle valve that blows down the dryer as the pressure rises. If that shuttle valve fails or gets hung up it blows air out the bottom vent faster than the compressor can pump. Another option is to purchase an overhauled dryer from NAPA or others that sells rebuilt dryers. The rebuilt option is the easiest and isn't much more expensive than the parts to rebuild.

The Dessicant kit (Upper) has a filter and dessicant package that drys and filters the air. Over time the dessicant can break down and send white powder throughout the air system (not good).

The Lower kit is ignored but that's the one that can put you on the side of the road.

Kit numbers:
Lower DQ6020

Dessicant(upper)  DQ6026 complete

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Re: Brake Filter Air Leak ?

Reply #7 – July 30, 2019, 10:18:06 pm

Thanks to all for your help.  This site continues to amaze me with the knowledge and sharing.  It is a big reason that I went with a FT.

Thanks again to all. I just hope that I am able to contribute and help someone along the way.

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Re: Brake Filter Air Leak ?

Reply #8 – July 30, 2019, 10:33:55 pm

I had same problems. Was able to reset by put my finger into opening and reset valve. Made 900 trip without blowing off again. Replace whole unit with new air dryer. Hope it works for you?

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Re: Brake Filter Air Leak ?

Reply #9 – July 31, 2019, 03:12:54 pm

Mark,
Part number for Haldex reman. dryer assy. is DA33100X on my 99 model  I replaced mine a couple months ago and the best price I found locally was about 325.
Jerry

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Re: Brake Filter Air Leak ?

Reply #10 – July 31, 2019, 10:28:31 pm

Again, everyone here is a great help.  I found a remanufactured unit from  Find It Parts and its on the way.  Was going to get the two rebuild kits, but the whole reman. unit was not much more.
Thanks again to all for you assistance.  It is much appreciated.

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Re: Brake Filter Air Leak ?

Reply #11 – July 31, 2019, 11:27:35 pm

Replace  components per manfactures very conservertive intravels and you should have good luck, my Bendix unit lists motorhome service intrevals which are greater than a typical otr truck use, as it should be.

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