1998 U320 Allison retarder accumulater solenoid Part number needed (29530324 obsolete). Any help would be appreciated if you know the new part number and a good place to pick one up. (Drama outlined below)
During a gas run today I had a total failure of my accumulator solenoid. I had noticed my primary tank leaking down after leaving the fuel stop. I have a new Haldex check valve on the primary tank that is cavitating causing it to make noise as air comes into the tank. It was making almost continous noise and I noticed the primary tank pressure dropping to 80 then climbing again.
As the leak got worse, the primary tank pressure stayed around 70 and the secondary tank started dropping as well. When I exited the interstate, the pressure would dive due to the lower rpm's and brake application. I had to keep it around 1600 rpm to maintain the level system and keep the low pressure alarm from going off. I just shifted manually to lower gears.
In town, every stop was a challenge to recover from so we limped the beast home at very low speed (2cnd/3rd gear). When we got back home, the air was dumping out of the accumulator solenoid with no restriction.
I just thought I would share the symptoms if you ever see these things happening with your air pressure. This is also why the protection valves are so important to maintain.
This might be what works now just have to make sure. Find it says it is an alternative valve.
Search for '29552377' (https://www.finditparts.com/search?s=29552377&search_method=fallback&sellable=true)
Thanks Craneman! I will probably have to call Brad at FT and see what the latest part number is.. Apparently they have changed this valve many times. Must be a design challenge for Allison.
Rex,
If the one you have is the old style from '98 you can take it apart and clean it. Worth a try and can save you a $ or 2.
Allison retarder air valve (https://www.foreforums.com/index.php?topic=31477.msg277542#msg277542)
The last time I bought one the part number of the month was 29555434
Mike
Thanks Mike! I tore it down and it is trashed. It is completely frozen up inside. I lubed it, and played around with it to no avail. It is like the plastic or metal inside the block expanded or the valve block shrank. super tight. I will check out that part number. Much appreciated.
Dear Madmaxx,
And others. The solenoid valve and hydraulic accumulator, in their function, can be replaced with standard industrial components. So not being able to find the original Allison or Foretravel part is not the end of the world.