Checked fluid level with shift keypad, strange result?

[Dave_H]

A while back had my Allison transmission serviced at Cummins shop. It is a 3000 6 speed model. They changed filter and replaced fluid with 19 quarts of Valvoline SynGard, (according to work receipt) which I believe is the correct amount also according to Cummins Quick service website. Got home yesterday from a trip and stopped in a nice level parking lot to just check fluid level with the keypad. Let it idle for 5 minutes but every time I entered the check level mode, it would never go into the countdown but would immediately display O,L,L,O,4. Tried many times with same result. Parked the coach in my driveway which is not level so the front end was lower than the rear. Entered the test mode on the keypad and this time it entered immediately into the 2 minute count down and display showed O,L,L,O,3 which I know is not accurate since being not level. Is it possible that when checking it on the level surface the fluid level was too low that it could not test correctly? Considering whether I should add 2 quarts and check it again when it is at the appropriate temperature. What else could cause this this discrepancy in the readings?

[Randy125]

Do you have a dipstick that you could compare with the electronic fluid check ?

[jacwjames]

If you let the coach sit for 5 minutes I don't think you'll see it do a countdown. The first time you checked it I think it shows 4 quarts low.

The second time you checked it with the front lower it may read 3 quarts low depending on where the level sensor is.

I'd suggest adding a couple quarts, taking it for a short drive to get it up to temp and check again.

I changed filters last year and added a quart figuring that was what I lost. I then drove it and checked the oil, showed two quarts low but I was skeptical so added just 1 quart and checked again and it showed OK. It's a lot easier add then take out.




NOW the big question is why did you loose that much oil, do you have any visible leaks?

[Dave_H]

The first time I checked it when level, I did let it idle for 2 minutes and got the 0,L,L,0,4 but never went into the countdown mode. After 5 minutes tried again with same result. As far as any leaks, I have never seen any drips on my driveway or while parked in my garage. I am questioning whether the shop actually refilled with the appropriate amount of fluid. Unfortunately this would not be the first time I would have to correct their work after any service preformed. Due to some other issues I have had recently with them, I will be using a different shop in the future when needed. I will add 2 quarts and recheck.

[Dave_H]

Originally Posted by Randy125

Do you have a dipstick that you could compare with the electronic fluid check ?

I did also check with the dip stick and was very hard to actually see where the fluid level was. After 5 reads it did appear it was close or within the Hot level on the dip stick but as many others would agree, the keypad reading is probably much more accurate than the dipstick.

[Skip426]

Sitting at idle ; you've probably over ridden the count down .

Trans total fluid capacity is 26 quarts PLUS what ever fluid cooler the chassis builder installed .
If the coach sat with filters removed for a length of time chances are some drained from the cooler circuit .

I'll bet the mechanic didn't drive the coach to get a reading from the shift pad , he just added the fluid change amount ( actually 2 quarts more than the change amount , listed in this document ) got a reading on the dipstick and called it good .

JMHO: I agree with Jim; There is a real possibility the trans is 4 quarts low ; add 2 quarts and retest .

[Randy125]

Originally Posted by Dave_H

I did also check with the dip stick and was very hard to actually see where the fluid level was. After 5 reads it did appear it was close or within the Hot level on the dip stick but as many others would agree, the keypad reading is probably much more accurate than the dipstick.

I’ve read that here that the key pad much more accurate but there are a few things that can make the system inaccurate and for that reason I always compare with the dipstick reading.

[Jim Simon]

Dave, did the keypad ever read correct? I have the same low 4 reading and after i added 4 qts it still read low 4.

[dons2346]

I check my fluid when we pull into a rest stop. That way the xmission is at operating temp, you won't get a good reading or possible not one at all I pull in, shift to neutral, set the brake and then enter the test mode and let it run. It will go into a countdown sequence before giving the correct code

[Dave_H]

Originally Posted by Jim Simon

Dave, did the keypad ever read correct? I have the same low 4 reading and after i added 4 qts it still read low 4.

Jim, I added 2 quarts and it did show 2 quarts low. Added about another 1 1/2 quarts and keypad shows OK.