When I replace the Haldex dryer I would like to service the isolation valve. I have read here it is easy to do and cheaper than buying a new one. I have also learned that special O rings are needed. Where are these O rings sold? Cummins parts house? NAPA?
Just buy the kit then you get all the parts you need for the isolation valve.
DQ6020 by HALDEX - Lower Housing Repair Kit (https://www.finditparts.com/products/365442/haldex-dq6020?srcid=CHL01SCL018-Uvconfirm&utm_campaign=confirm&utm_medium=email&utm_source=orders)
I'm going to get a remaunfactured unit, so the only thing I'll need is the o rings. ..... I think 🤔. I need to replace it and I'm trying not to talk myself outta doing it myself
The last time I replaced our dryer, I installed a new isolation valve. I figured I would take the old isolation valve apart, clean it up, and keep it for a spare. Well, I could not get the sucker apart! I used the biggest wrenches I had, applied extra leverage with a cheater pipe, used a propane torch to heat it...tried every trick I knew from working in the oilfield. It would not come apart. I finally gave up...it's still sitting there on my work bench, mocking me every time I look at it.
My advice: just buy a new one.
Haldex KN23500 N15842H N15842J Air Compressor Solenoid and Isolation Air... (https://www.ebay.com/itm/Haldex-KN23500-N15842H-N15842J-Air-Compressor-Solenoid-and-Isolation-Air-Valve/192400220574?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D47301%26meid%3D57cc2945d3a94f2d901a65113a999327%26pid%3D100623%26rk%3D1%26rkt%3D6%26sd%3D162226584727&_trksid=p2047675.c100623.m-1)
Haldex Isolation Valve (http://beamalarm.com/Documents/haldex_isolation_valve.html)
Here is another view
To the best of my knowledge, neither of the two overhaul kits (both needed to do a complete overhaul of the dryer itself) include the isolation valve 'O' rings. I did a lot of searching for info on the Isolation valve when I had a failed air dryer in Canada. I couldn't get the parts and so was forced to have the air dryer rebuilt by a reputable company. I talked to their tech, and he had never heard of the isolation valve. I printed up information and sent him some links, but when I received the rebuilt air dryer and removed the piston on the isolation valve, I could see that different color 'O'rings had been installed. My research indicated that the 'O' rings needed to be of a particular material and said material was a certain color. So I suspect that the tech just went by size and replaced them with what he had on hand. Maybe they were fine, but when I got home I found new old stock isolation valves (Haldex KN23500) on eBay for a very reasonable price. As they seemed commonly available there, I have bought several and have a new spare ready to go. Here is a link to one eBay auction for the Haldex KN23500 (https://www.ebay.com/itm/Haldex-KN23500-N15842H-N15842J-Air-Compressor-Solenoid-and-Isolation-Air-Valve/192400220574?hash=item2ccbf2619e:g:XHUAAOSwR6RaDjp8&vxp=mtr).
Attached also is a pdf of the Haldex instructions.
Don
OK sounds like the best thing to do is just buy a new one and not mess with rebuilding the old one. Looking at all the research that I've done it looks fairly straightforward to replace it is there something I'm not seeing. I'm halfway mechanically inclined so I think I can do it but I'm just apprehensive to try.
Keith,
You have to have the mindset like this thing was put together by human hands (not like your transmission as it was built by magic) and you are a human so this is a DIY job. Look at it like this: it isn't but 4 hoses (that won't hook up but at one place) , 2 wires that run your heater, 4 bolts that mount the dryer, and the 3 pipe fitting that are on the isolation valve. If you are somewhat mechanical there ain't nothing to it but do it. If you get stumped you have all of us here that will get you back on track.
Mike