Common leak

[dorin18]

Hello everybody
I have a ’87 Ranger, 2x4, 2.9L with automatic transmission.
I use the truck mostly for short trips, but from time to time I take it to highway and then the transmission fluid will start pouring from the front of the transmission.
I know this is a common problem and AllanD recommends checking the venting tube (I have the small vent on top of the transmission towards the end of it) or checking the transmission cooling lines.
I couldn’t take the cap of the vent off, so I couldn’t tell for sure that the vent is working, but the cap is moving freely and I would think it is ok.
In regards to the cooling lines…they are ok, no sharp bends, but I just saw that the circuit that goes through the radiator was cancelled and the only cooling for oil is given by a small radiator in front of the car. It is a 4”x8”radiator without any fan. I am wondering if this radiator is big enough for the transmission. I do not tow anything with the truck.
Somebody mentioned the possibility of a clogged inline filter. I didn’t see any filter on the cooling lines. Where should I look for it?
So, do you think that just replacing the pump seal and inline filter (if applicable) will take care of the problem, or it might me something more serious that requires disassembling the transmission?
Thank you all for your help!
Dorin

 

[RangerSVT]

Go to your local autoparts store and ask them for some fluid dye. I forget the name of it, but there is something new out that is a dye on one side and a sealer on the other side, its a 2 part product, but you use an ultraviolet light to detect the leak. I would advise against using the sealer, as most sealers don't work, but at least you will be able to tell where you leak is. As far as the trans cooler, I would look into running your cooling lines through the rad as it is supposed to be. Running just through an aftermarket cooler alone, especially one as small as you have, does not sound like it is getting the proper cooling it needs, reducing your tranny's life. It does sound like your input shaft seal is leaking. While you are at it, it may be a little more, but I'd run mercron 5 atf, as it is a synthetic atf and withstands higher temps than regular atf.
SVT

 

[dorin18]

Thanks for replying.
I'm 99.9% sure that the leak is from the front seal, considering that I saw the fluid pouring from where the engine bolts to the transmission.
I just want to understand how the lines suppose to be connected with the engine’s radiator. Is this a “series” connection or a “parallel” one? If it is a series connection, does it matter what radiator is put first?
I don’t know why the engine’s radiator has been disconnected in the first place. Maybe it is leaking?!? However, in case I cannot use the engine’s radiator for cooling the transmission, how big should be the remaining radiator in order to properly cool the transmission?
Is there an old car that has a big radiator that will work for me? I’m thinking of an old car since the parts for it should be cheaper in a junkyard…

 

[RangerSVT]

They are series ran, and usually you would run the rad first, as the heat from the coolant will keep the temps only so low, as with the external cooler there is no other fuild that runs beside it, so it cools a little more effectively. IMO I would find a replacement rad out of a junkyard, as any aftermarket cooler big enough to fit your application would be about the same as a used rad, odds are it was disconnected from the rad cause it did start leaking, not because the previous owner had cooling issues.
SVT

 

[dorin18]

Many thanks for your answer. I will try to connect the lines to the engine radiator and look for leaks. If it leaks I will either look for a radiator replacement or for a bigger cooler.
Thanks again!