PTU fluid exchange problem/question

[Tstaats]

I search for this and couldn’t really find an answer to my particular question. I recently bought a 2014 PIU with 120K and a cooler on the PTU. I drained it (hot) an hour ago and only got 8 oz. of fluid out of it after it had stopped dripping (again, hot and an hour of letting it drip). Now I’m concerned about how much fluid I should put back in it. I did the “vent hose mod” (replaced the vent hose with a longer section to make adding fluid easier). Since it has a cooler, there is a sensor in what would be the fill hole. I really don’t want to take that sensor out but I may not have a choice. As far as refilling goes, the old style without a cooler would be easier to correctly fill, since it would start running out of the hole that the sensor now lives in. I know 8 oz. definitely isn’t nearly enough but I don’t want to go cramming more than say 12 oz in there and risk overfilling it. I’m stuck. Anyone have any ideas other than removing the sensor??? Thanks in advance!

 

[peterk9]

I was unable to find the capacity in the PIU Owner's Manual but the 2014 retail Explorer has an 18 oz. capacity.

Peter

 

[Eric Z]

I search for this and couldn’t really find an answer to my particular question. I recently bought a 2014 PIU with 120K and a cooler on the PTU. I drained it (hot) an hour ago and only got 8 oz. of fluid out of it after it had stopped dripping (again, hot and an hour of letting it drip). Now I’m concerned about how much fluid I should put back in it. I did the “vent hose mod” (replaced the vent hose with a longer section to make adding fluid easier). Since it has a cooler, there is a sensor in what would be the fill hole. I really don’t want to take that sensor out but I may not have a choice. As far as refilling goes, the old style without a cooler would be easier to correctly fill, since it would start running out of the hole that the sensor now lives in. I know 8 oz. definitely isn’t nearly enough but I don’t want to go cramming more than say 12 oz in there and risk overfilling it. I’m stuck. Anyone have any ideas other than removing the sensor??? Thanks in advance!

I am not sure my 2015 has the "sensor" you refer to, but.... Given the Vent tube you are filling from, is just that a vent, why not fill it as much as possible?? The only downside I had from this method was that some "burped" out after coming up to temp and I had to clean that up.

 

[MattMPA]

I put back as much as came out added via the vent tube.

On my 2018 SHO, there's only the higher-up plug, so I draw it out with a vacuum brake bleeder and refilling until it dribbles out the same hole. When I do this, the amount that I am able to remove isn't the full capacity.

Obviously, can;'t do that in the utility, well, at least easily...so I put in as much as came out.

My thinking, perhaps faulty, is that unless there's leakage, the level shouldn't change much and should be good when you put in as much as comes out. I'll do it again next time I change the oil. I did the SHO the first time when at about 8000 miles and was surprised how bad the fluid looked. I've done it every oil change since. I suppose it's a bit of overkill...