Checked hydraulic pressure in rear tag and found I only had 50 psi on the hydraulic side and 50 psi on the nitrogen side, coach drove fine , would back up and the rear wheels turned the way they should, accumulator is probably original, 20 years old. Good chance bladder is ripped, I wonder if the best way is to remove the accumulator and turn it so the fill port is at the top, let it sit for a while so the nitrogen can make its way to the top and let nitrogen out, or do I let out oil at the junction block and hope nitrogen does not end up in the system
If the diaphragm is ruptured there is nitrogen in the system, however the folks at Newell said it doesn't get through the entire system since it is a closed system with no pump. I bled the system at the junction using Minimess fittings. There was a lot of fizzy fluid initially when I released the pressure. I left the system open overnight and didn't see much when I put it together & bled it the next day.
Yes, you will need a new accumulator.
Be careful backing up if the tag doesn’t function you could be in a position that you’ll need to maneuver to straighten out the tags if they turn in the wrong direction.
I was recently told by Newell parts department that the ZF accumulator is not available. Newell is using a replacement accumulator.
If you contact Newell they can explain how they have been installing the new style accumulator.
You may also inquire if the unit used to bleed and pressurize the system can be shipped to your location. If that is possible you could circulate fluid throughout the system to re-bleed and then set the hydraulic pressure.
I had my tag system set the ZF recommended values:
Nitrogen 10 bar
Hydraulic 15 bar.
Is your original accumulator not installed with port up?
Others have replaced their accumulators and set the pressure themselves. You’ll need to put together a manual hydraulic pump system.
Kristi & Jeff King
Bentonville, Arkansas
#744 2005 45’ Newell Coach
ZF Suspension/Active Steering Tag Axle
CAT-13 ACERT KCB Engine 525HP 1642 ftlbs Torque Cat Compound Turbocharger 43.5 psi
Allison HD4000MH Transmission with PTO drive.
My accumulator nitrogen access port is at the bottom with the hydraulic hose at the top. I would have to remove some air lines to get enough slack in the hose to invert the accumulator, I think I will remove the schrader valve from the accumulator test adapter and have the nitrogen and oil come out the charge hose. Iron wing sales has 10 accumulators in stock, but will not ship hazmat items across border so i will have to get it shipped to Buffalo and drive down and get it. They will not let the nitrogen out so it could be shipped across border. I bought a cheap Chinese water pleasure test kit with a hand pump that goes to 750 psi I just have to make a new tank for it, otherwise I will flush out one of my enerpac hand pumps and fill it with synthetic atf and use it
Don't think my bladder is ruptured, used accumulator test fixture with schrader valve removed from charging port, port on bottom so if bladder was ruptured oil should of been on bottom, opened port had the other end of the hose in a can that had some atf from something else I had been working on, only nitrogen came out. The charge hose for the accumulator has fitting to go right into nitrogen bottle, I was taught never to use a nitrogen bottle with out a regulator, so I will have to adapt that hose.
Have no light on dash with 0 psi in system, pressure switches seem to fail often has anybody thought about installing it on a minemiss connector you don"t have to reduce pressure to 0 to change it, and you can check to see if it is working just by removing it.
The pressure switch on mine, Noshok 300L 15/230psig is rated for 870psig and did not turn the dash light on since the wires on the switch were connected to the wrong terminals. I did test it as good and replaced on principal.
(11-23-2024, 08:44 AM)johnkosir Wrote: Iron wing sales has 10 accumulators in stock
May be a good idea for Iron Wing to check the date stamped on the accumulator. I didn't do that and realized it was a 2008 accumulator when I installed it.
Jim
2014 Newell Coach 1482 Mid Entry 45'8" Valid Slides and Valid Levelling
Charged accumulator to 250 psi with nitrogen, junction block pressure was 250 psi, so I think that my accumulator is working, I know without letting oil out and finding what my initial accumulator charge is I have no idea how much oil i have in accumulator. I have a cheap pump that is suppose to go to 750 psi but the tank is useless will let all kinds of dirt in, I think I will put the pump in a plastic bag and see if it works, before i spend time to make a new tank to find out the pump does not work. then I can let oil out see if there is nitrogen in the oil, check initial nitrogen charge, 2 weeks ago the coach backed up with the tag wheels turning properly, I think there was only 50 psi in accumulator, that was what was in it yesterday, It is $10 more to ship accumulator to Tampa then to Buffalo and I do not waste a day going to get it.
