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D2 air governor quality

I am wondering if any others are seeing what I am seeing with the quality of recently purchased air governors.

I replaced my Air dryer recently, and while in that area went ahead and got a new D2AG. The first one i ordered from Napa at the same time as the Dryer. Once all was installed, system was up and running, but the D2AG was cycling between 90 -100. As my old one was more like 90 - 120, using the adjustment screw, got it to take the high side up to 120. However, once the upper desired was achieved, the lower would never engage, even after a few love taps, nothing. No way no how would it allow air to pass. I then took it back down to the 100, and at that point, the 90 would open and allow air to pass. Pretty much anything above a high side 105 and the lower would die. As long as I kept it at 90 - 105  it appeared to work ok.

Not really happy with this operation, I ordered another D2AG. This one out of the box would do 90-115. Not quite where I wanted it to be but a more tolerable range closer to what I wanted. Took it for a few small drives, and all was ok. This weekend while working on some air leaks, this 2nd unit got the air system up to the cutoff of 115, but after a few cycles now will not open at all at the lower end even after a few light  hammer love taps. at the moment air system is about empty and here I go again having to tinker with a brand new D2AG.

We were  planning to road trip this weekend and at the moment figure I am going to have to go back to the original 90-120 I pulled off when I installed the new dryer.

Am I the only person seeing quality issues with these items? All are Bendix brand. Is there another brand with higher quality?

Re: D2 air governor quality

Reply #1 –
When I need a fresh D2 I go to my spare parts stash of a half dozen that I bought off eBay 6 or 8 years ago.  I have not purchased one recently.  Perhaps you got a lemon, or NAPA is selling cheap rebuilt parts as new.  I see you posted a complaint on the NAPA web page.  Let us know if they respond.

https://www.napaonline.com/en/p/MBI275491RX

Re: D2 air governor quality

Reply #2 –
Most parts are now junk. I know a mechanic that switched careers over it

Re: D2 air governor quality

Reply #3 –
Quote from: Chuck & Jeannie –
When I need a fresh D2 I go to my spare parts stash of a half dozen that I bought off eBay 6 or 8 years ago.  I have not purchased one recently.  Perhaps you got a lemon, or NAPA is selling cheap rebuilt parts as new.  I see you posted a complaint on the NAPA web page.  Let us know if they respond.

https://www.napaonline.com/en/p/MBI275491RX


Nothing so far.

Re: D2 air governor quality

Reply #4 –
Just curious.  I recently purchased a spare, but couldn't find a new Bendix anywhere.  Everything seems to be remanufactured.  Does anyone know if these parts still manufactured an , if so where can they be purchased?  Remanufactured parts always seem hit and miss, and I'd rather pay a few more bucks for a new if possible.

Re: D2 air governor quality

Reply #5 –
I've been buying Bendix reman. From Franklin Truck Parts which is all over So. Cal. I see that they now sell on the web. Never had a problem with the Bendix reman. Maybe things have changed, like the other Chuck I have a ready supply of them in the shop.

Re: D2 air governor quality

Reply #6 –
Both Of the bendix brand I have bought I am sure are remanned....I just ordered a Torque Branded one from amazon, as will be here b4 our trip.

Re: D2 air governor quality

Reply #7 –
Quote from: Joe Phebus –
...couldn't find a new Bendix anywhere.  Everything seems to be remanufactured.  Does anyone know if these parts still manufactured an , if so where can they be purchased?
Google is your friend.  8)

Bendix New D-2 Governor 275491N

275491N by BENDIX - D-2® Air Brake Compressor Governor - New

Genuine Bendix 275491 D-2 Governor, 100-120 PSI (NEW): AnythingTruck.com,...


Re: D2 air governor quality

Reply #8 –
When I get a chance I will take one of mine apart and show pictures. I have fixed mine on the road in my crane when I wasn't carrying a spare. Very simple, some O-rings, and a spring would be the major parts. They are usually gummed up and brake cleaner fixes that some O-ring lube and they are working again.

Re: D2 air governor quality

Reply #10 –
Quote from: craneman –
When I get a chance I will take one of mine apart and show pictures. I have fixed mine on the road in my crane when I wasn't carrying a spare. Very simple, some O-rings, and a spring would be the major parts. They are usually gummed up and brake cleaner fixes that some O-ring lube and they are working again.
Well Im about to the point with 2  supposedly new, that appear to be useless at the moment, tear them down and get them working. Ive been in to one in the past, and as you state, not really much to them.Hard to imagine a fresh remanned being gummed up, but with the quality of things nowadays I guess anything is possible.

Re: D2 air governor quality

Reply #11 –
When I bought 2 in the past I searched for " new old stock Haldex KN18530 D2 air governor ".

I used one of them in 2021, carrying the other for a spare (and already configured the plugs to match what was on the coach).

Ebay both times. New old stock was more money than the cheapest available.

Re: D2 air governor quality

Reply #12 –
Pictures of the D-2 parts. My observation for the 30 psi. spread, (90- 120) (100-130) is a result of the casting ports, not changeable. The pressures can be moved up and down easily as many U-tubes show. The 2 O-rings are around .1" material diameter and not in any of my kits. I might go to a Ace Hardware and match up some for spares as the ones in the picture when installed on the piston are too loose.

Re: D2 air governor quality

Reply #13 –
Crane,
thanks for the detail. I took one apart on my bench last night, but never could figure out how to get that shuttle/center bore part out. What did you do to get it to come out?

The inside of mine was pristine clean, and lubed with some sort of grease looked to be like silicone grease. Of course this was the one I had removed at the time fo the dryer upgrade as i knew nothing of its history. looks like it is ok, will fresh grease then probably put it back on. The other 2 are the ones that something is obvioulsy stuck or not moving.

Thanks, Mike
 

Re: D2 air governor quality

Reply #14 –
The white piston has nothing holding it in. Just tap the valve with the open end down on a solid surface a few times and it comes out.