ATF fluid check with external filter

[Lee S.]

I have the perma cool external tranny filter set-up on my SOHC with the 5spd. auto trans.. When I check the fluid level when warm with the engine idling in park the level is right in the middle of cross hatch area. When I check the level cold with the engine off, the fluid level is almost an inch and a quarter above the top of the cross hatch. Just wondering if this is normal? For some reason I thought the cold level would be lower (not higher like mine) than the hot idling level.

I'm starting to think I may have screwed up on the external tranny filter install. Could I have the lines reversed perhaps? Tranny runs good but I really haven't tested it on any long trips........just mostly around town. External filter is warm to the touch say after a 15 mile drive but it never seems real hot.

Any thoughts or advice?

Lee

 

[Billy177]

the only thing i can think of is the filter does not have an anti drainback valve so it drains back into the tranny. how did you mount the filter?

 

[Lee S.]

The tranny filter is mounted horizontally in the front passenger side wheel well.....the same as the majority of others who have done this mod as far as I can tell.

I have used both Motorcraft FL-1A and Purolator Pure One (#30001) filters. Get the same different hot/cold level readings previously mentioned regardless of filter used. Don't know about the anti-drainbacks in either of these filters but I wouldn't suspect that to be a problem.

I might just be paranoid and things are actually working the way they are supposed to. I know a lot of members have done the external tranny filter mod. Hopefully some of you can take hot/idling and cold/engine-off level readings and let me know if you get the same results as me.

For the record I only did this mod about 200 miles ago. Started with the pos filter they give you with the kit and left it in for only about 20 miles. Then I went to the motorcraft FL-1A. Then I did a pan drop. Today I replaced the FL-1A with the PureOne. Once again no long trips to really tax the tranny and I'd really like to make sure I've got this right before I find out the hard way.

Lee

 

[Billy177]

well the manual startes to get an accurate reading only check when it is running. i am sure there is a good reason for this so i wouldent worry

 

[Opera House]

A portion of the fluid drains out of the TC (which holds a lot of fluid) when the the engine is stopped. That is the reason the fluid level is higher with the engine off. Depending upon placement of filter that may add a little. TC may drain fast or slow so measurments with engine off have no value. Fluid also expands when hot so it should only be checked when warm. Check valve serves no useful function since this is basically dumped fluid going back to the pan.

 

[Lee S.]

Opera House....I knew there was a reasonable explanation for this. Thanks for curing my paranoia.

Lee

 

[aldive]

My filter gets a lot hotter than warm to the touch. Do you have a tranny temp gauge?

 

[Lee S.]

No tranny temp gauge Al. But I'm up in NY and it's been a cold winter. Like I said, I really haven't driven the truck for much more than 15 miles since the install. With the cold weather I do not think 15 miles is even enough to get the filter hot.

I took a second look at the install today. The lower tranny line from the tranny goes to the upper fitting on the radiator. The lower fitting on the radiator goes to the external filter. The other fitting on the filter goes to the tranny cooler and the other fitting on the tranny cooler goes to the upper fitting on the tranny. I think this is the correct install but if anyone notices a fatal error in it let me know.

So, I'm thinking that that the ATF might already be partially cooled by the radiator and then enters my filter before it goes to the tranny cooler and back to the tranny. This partial cooling by the radiator along with the cold weather and short driving distances since install may explain the filter not getting hot.

For the record, I did do the test at the filter mentioned in a previous thread. Took the filter off, had my wife crank the car with the coil pack disconnected and observed the flow at the filter housing. The ATF came out of the side port on the housing (as opposed to the center) like it's supposed to for a correct install.

Guess I'll just have to wait for the summer and some longer drives to get the thing hot unless anyone notices somethings amiss with my install.

Lee