1998 HR Imperial Bummed !!!

Rver13 · 05-23-2010, 11:19 AM

I'm having some minor (I hope) problems with the coach.
First a couple of days ago about Tuesday this past week I fired up the
coach and after letting it run for awhile to bill up the air pressure
the tranny would not engage. It's a Cummins 325 Turbo, Allison MD 3060
6 speed. Push button shifter with the troubleshoot capabilities. Only
code I can get is a 7-0 which by the book is sump pump temp too low.
Twice in the past few days it worked, but then this am no go, even
after warm up, SOS. I have looked online, checked the fluid at the
tranny, and the shifter, fluid is at bottom of hot safe range, good
according to the book. Checked the jacks, fluid for the jacks,
everything as far as I can tell is OK, Nothing that I can come up with
as to why it's acting up.
Second is now my ABS light comes on, stays on.... It came on on the
last trip but it always went back out until now, its on every time I
fire it up. Comes on, goes out then comes back on, stays on......
another head scratcher.
Any input will be greatly appreicated.
Thanks in advance for any info you may provide.
Bummed out.
Roy

Corkey · 05-23-2010, 11:15 PM

The very same thing happened to one of my club members.

This may not be your problem, but what we found on his was a bad isolator that splits the alternator charge to the coach and chassis batteries. the bad isolator prevented the charge from getting to the chassis battery. The low battery prevented the shifter from going into gear, just stayed in neutral. The battery still had a charge and his cockpit instrument's still functioned, but the charge was too low for the transmission to allow it to shift into gear.

We replaced the isolator and everything went back to normal and has worked fine for over a year now. It's sure worth a look.

bdpreece · 05-23-2010, 11:21 PM

If it were mine I would disconnect the batteries, remove and clean all connectors at the shift pad and also at the transmission then reconnect the batteries and test. For the ABS light problem you need to remove and clean the sensors at each wheel.

Rver13 · 05-24-2010, 07:24 AM

Thanks for the info, it's worth a look.........
Thanks again
Roy

Rver13 · 05-24-2010, 08:42 AM

The allison trans is fine.........
the problem was the OHS sensor was bad and the nut behind the wheel was loose. tighten the nut, replaced the OHS sensor all is well... Thanks for all the input...

FYI ... OHS = Operator Head Space ...

Roy