Simply for your recall if you notice this symptom. At various times cranking the engine the tank pressure would not build above 70 psi regardless how long I let it sit (within reason), even at high idle. I would shut it down, crank again and so forth until finally got the pressure to build. I faulted the D2.
Turns out it was the air dryer system. It costs less to replace with a rebuilt one than to have someone rebuild this one and the overall expense was not high as coach projects go. IF I understand what was happening, as the mechanics wear, there is a pressure release thing that my mental picture is a plunger that seals off an air flow and that opens to exhaust air. One of these things was sticking open so air just bypassed going where it was needed for tanks. I wanted to take photos of how this is put together but it was discarded by the time I got around to that. Anyway the mechanical part is that below the Haldex air filter and I can take photos of the outside of the system if anyone really wants that.
Mike
Pamela and Mike posted discussion of this a while back - I think they included photos. I'll try to find the post to link here. They, or perhaps it was Barry and Cindy, made us aware that one could buy a reman'd Haldex Pure Air Plus for barely more than the cost of the minor rebuild kit (most places we've been don't replace that valve during air dryer service because it can snap off during removal and make a small job much more complex).
My was the air controller valve . Gummed up over the years. Maxed at 100-105 psi.
Now its 110 low and 130 high. The air brakes work much better with the higher pressure and I can fill all the coach tires now internally.
Bob, yours wore out about the same time that mine did. Being close on the build numbers of our coaches. Mine went out three days ago on the road. I have 125# now and air horns are louder also.
Any suggestions on where to buy the re-built units?
Any big truck supply parts company. The one down the street a mile from me had them in stock. The price of a rebuilt is not much more than all the rebuild kit parts.
They also keep D2 regulators behind the counter and hand them out without even looking away when you ask for one.
We got ours (and our spare D2 governor) at the local NAPA. The governor they had on hand (less than $20); the reman'd air dryer had to be ordered from the warehouse, took 2 or 3 days. As part of the dryer purchase you'll pay a core charge (around $99) that will be refunded when you return the old air dryer in the new one's box. Net was around $250-255. DA33100X
Midland/Haldex Pure Air Plus Air Dryers - AnythingTruck.com (http://www.anythingtruck.com/category/htp-brake-air-dryers-pureairplus.html)
$306 plus shipping
Just FYI, we paid $305.61 for it at MOT, plus tax but no shipping was added on.
Lon,
After our trip up from FL, this spring, I changed out our air dryer during my Main and Gen. LOF exercises. I have used air dryer rebuild kits twice in the past 14 years, so that's about a 4.5 year mean-time-between-service interval. I have never seen moisture from the tank drains or any signs of powder residue out of the desiccant filter, including this most recent service.
The 1998 coaches use a DA33100x (Remanufactured exchange unit). My cost would be $334.19 from Haldex, Peterbuilt, or Cummins. All come from the same N.E. warehouse.
The new version of this is a DA34100. My cost would be $440.39 from Haldex, Peterbuilt, or Cummins.
Both units can be shipped from the New England distribution center on a stock order to Peterbilt or Cummins at no additional cost.A new KN23500 isolation valve is also available at $96.83. I rebuilt my original isolation valve with 3 "O-rings" from Cummins. The old "O-rings" were not in bad shape. They
are "special O-rings", based on composition, though. I don't know the material, but "hardware store O-rings" wouldn't last, according to Cummins.
I opted for a NAPA DA33100x (Remanufactured exchange unit). I have no idea if it means anything or not, but the brand new, sealed Midland carton that the NAPA unit came in looked identical to the Haldex, Peterbilt and Cummins cartons, in terms of the Haldex-Midland markings. My cost was $264.00 with a $99.00 core charge (refunded when the removed unit is returned to NAPA), overnight availability, no shipping cost. Which is exactly the same as Steve reported (NAPA in TX). NAPA fidelity!
FWIW,Neal
Thanks .
Looks like it couldn't be easier with NAPA as the parts source.
Haldex info. Manuals, identifying units, parts.
http://www.haldex.com/North-America/Applications-Products/Literature/Brake--Suspension-Systems-Literature/Airline--Air-Dryers/ (http://www.haldex.com/North-America/Applications-Products/Literature/Brake--Suspension-Systems-Literature/Airline--Air-Dryers/)
Keith