-
Air Dryer Cartridge
After leaving Branson last week, I went to Prevost FW to have a level 3 and air dryer service. Well, everything went pretty good till I came back from lunch only to find 2 techs up under the bus grunting and making noises I am all too familiar with and a couple of cheater pipes and some 4 foot long pry bars lying on the ground. Scared to ask what the problem was, I stood back and watched (very inocent looking) till one of them finally came over and told me they couldn’t get the cartridge off the dryer asembly. Longer story short had to replace the hole assembly. When they got the assembly off the bus they had all but torn the cartridge in half trying to get it off.
Next time anyone gets air dryer service make sure they put a little ant- seize compound on the threads of the air dryer cartridge. BTW, I change this twice a year. (Not a Prevost problem, just one of those things)
-
13 Replies
-
Good advice, sometimes those filters are impossible to break loose. I just had the same deal with the coolant filter and it was put on in January (not by me) and I almost had to remove the housing to get it off. Once off, it wasn’t a pretty picture. Hand tight must not have been the method when installed.
-
The Wabco filter that takes the cartridge can be a problem because it is mounted high on the frame and it is difficult to even get enough leverage to remove a stubborn cartridge.
I never worried much about the threads, but I put white lithium grease on the rubber gasket every time I replaced mine. I don’t think the air is sufficiently cooled when it enters the dryer and over time that heat might contribute to the rubber gasket sealing itself to the cartridge base. Even with lubing the gasket I had to use a lot of force on my strap wrench to get it to turn. If it resists efforts to spin the cartridge off the solution is to take the time to remove the entire assembly and remove the cartridge on the bench.
Can we assume when the new cartridge was installed the gasket was lubed? If not that is job security for mechanics.
BTW, the Haldex dryer on later model coaches only requires four bolts to be removed and the can with the internal element lifts off easily.
-
$34 cartridge /several hundred $$$ air drier==good point. Mine has two rubbers 1 one the can and another internal around the inner seal both get lubed. also the threads.
-
I had mine changed at Prevost Jax. They removed the whole unit, took it apart on the workbench, no problems.
-
But did they lube the gasket(s)?
-
I have my cartridge changed at Prevost Nashville every 12-18 months and it is always difficult to get off. I had the whole dryer replaced this year so I am interested in how easily it comes off in the future.
DKO
-
I have serviced my air dryers every two years. When I had the one with the big snap ring (for lack of a better description) I got pretty good at servicing that one, but when I got my 97 coach with the spin on I thought that was the best thing going.
I will admit it made me grunt when I used a big strap wrench on the cartridge and it didn’t move right away when I pulled as hard as I could, but by pulling continuously for several seconds the cartridges would begin to move. Even a few degrees of turn made me realize the battle was over, and at that point it would spin off without having to use a length of pipe for leverage. In fact I never had an issue spinning them off. But I also never used excessive force replacing a cartridge. I would snug it by hand and give it a slight bit of additional rotation with the strap wrench. Lubing the rubber gasket was vital.
I think it pays to never let the mechanic use force to install a new cartridge. Spin on cartidges for anything, fuel, coolant, oil or air by design just need to be snug.
-
Hey do you guys have a part # for the Dryer filter/cartridge? How ofter are they supposed to be changed and what do they cost? My Prevost DMI showed mine to be pretty new but want to be prepared!
-
Gman…..I would be very reluctant to provide information on your dryer because there are so many different types that have been used, and then to go even further if a previous owner had an issue with it a different one could have been installed. I never had the same dryer on any of my three coaches. Your best bet is to contact Prevost parts with your VIN and let them tell you what you have. It has been my experience with the parts guys that if you ask for the trade number, and not just the Prevost number you can then shop for generic replacements if you wish.
-
Ditto what Jon said… Mine being an 02 I just assumed it was a spin on, nope, cartridge and a big PIA.
-
Yeah, the cartridge one on ours brought forth a few expletives from the normally unflappable Mr. Rowe.
-
Removal tool:
Forget a strap wrench and go big with a chain wrench!
-
If If If
You have a Bendix AD-9 air dryer, then the dessicant cartridge new is 107794, or reman 107796, these are Bendix part numbers.
The purge valve kit is: hard seat 5005037, or soft seat 5005893.
Re spin on filters, this past spring I replaced the coolant filter because it looked original, and it came off like it was the original. After there was no more metal left to the body of the filter, I used an air chisel against that top lip of the filter where there is a small roll in the metal giving it a little more thickness. It loosened immediately. It was a risk I took, and I do not recommend this procedure.
Log in to reply.