Pop off valve sticking, need correct term for the TMs

[kendelrio]

Ok all,
My pop off valve (when you build pressure it pops off) is sticking in the half open position after I build air, bleeding it slowly down.

I had this issue once before and for a temporary fix I followed the advice of @fuzzytoaster and used an extension and hammer to whack it back into place. Now it's consistently sticking, so I need to take it apart and see what's going on.

I know I could spray it with lube, but that only attracts more dirt etc, so I would like to clean it so it's "dry".

My issue is I don't know the proper term to search in the TMs. Any help?

 

[fuzzytoaster]

Time for a full rebuild or replacement. There's a few options in the parts cheat sheet depending on how are you want to do with it. Here's the cheapest service kit i found with a quick google search. Ebay link

Air Dryer COMPLETE UNIT "Air Plus System"	NAPA/MIDLAND/HALDEX	MBI DA33110X
Upgraded dryer from MRAP Contact Member Suprman or ZiggyO	HALDEX	N50011K
MRAP DRYER INSTALL BRACKET	NAPA	MBI DQ6051
Air Dryer FILTER KIT for MRAP N50011K Haldex Dryer	NAPA/MidLAND/HALDEX	MBI DQ6050
Air Dryer Repair Kit for ABS HALDEX "Air Plus"	NAPA	MBI DQ6026
Air Dryer Purge Assembly ( plunger with o rings) (Air Plus and Purest Dryers)	Napa/TruckPro/Haldex	DA33115
Air Dryer Lower Rebuild Kit (Air Plus and Purest Dryers)	Napa/TruckPro/Haldex

 

[kendelrio]

Time for a full rebuild or replacement. There's a few options in the parts cheat sheet depending on how are you want to do with it. Here's the cheapest service kit i found with a quick google search. Ebay link

Air Dryer COMPLETE UNIT "Air Plus System"	NAPA/MIDLAND/HALDEX	MBI DA33110X
Upgraded dryer from MRAP Contact Member Suprman or ZiggyO	HALDEX	N50011K
MRAP DRYER INSTALL BRACKET	NAPA	MBI DQ6051
Air Dryer FILTER KIT for MRAP N50011K Haldex Dryer	NAPA/MidLAND/HALDEX	MBI DQ6050
Air Dryer Repair Kit for ABS HALDEX "Air Plus"	NAPA	MBI DQ6026
Air Dryer Purge Assembly ( plunger with o rings) (Air Plus and Purest Dryers)	Napa/TruckPro/Haldex	DA33115
Air Dryer Lower Rebuild Kit (Air Plus and Purest Dryers)	Napa/TruckPro/Haldex

Thank you my brother by another mother!

In the TMs, what do I look for?

 

[kendelrio]

Kit is ordered and on the way.

 

[fuzzytoaster]

I found replacement steps in the 9-2320-272-24-2 Page 3-1022 but I didn't see rebuild steps for the dryer itself.

 

[kendelrio]

Thanks bud.

 

[kendelrio]

I found replacement steps in the 9-2320-272-24-2 Page 3-1022 but I didn't see rebuild steps for the dryer itself.

Well, it'll be the old "take it apart and put it together" method then!

 

[98G]

Well, it'll be the old "take it apart and put it together" method then!

Pressure protection valve opens the secondary side at 70 psi and supplies air to the wipers and horn and governor.

At 120psi the expello valve sneezes.

If the PPV fails, the sneeze never happens and you get pressure to 150psi at which point the pressure relief valve opens.

What i think you're suffering is the expello valve on the air dryer is sticking.

 

[Guyfang]

If you look in the TM section, for the M939 TM's, there is a newer version of the maint. manual. The TM 9-2320-272-24 series has been replaced by the TM 9-2320-23 series. There might be a procedure there to rebuild. Dont know. The -23 series is five books long.

 

[kendelrio]

Pressure protection valve opens the secondary side at 70 psi and supplies air to the wipers and horn and governor.

At 120psi the expello valve sneezes.

If the PPV fails, the sneeze never happens and you get pressure to 150psi at which point the pressure relief valve opens.

What i think you're suffering is the expello valve on the air dryer is sticking.

It's the one that normally sneezes at 120.

 

[98G]

It's the one that normally sneezes at 120.

Expello valve.