Change or Flush?

[Rokey199]

So I bought a 39 Ford with a TH375 and there is a little fluid leaking from the pan gasket. I plan to replace fluids, filter and pan but I have no idea what fluids are currently in the trans, my question is should I do a change assuming the previous owner had the correct fluid in it or would you recommend a flush.
I was planning on refilling with Valvoline Dexron VI and any recommendations for a filter? Any thoughts or recommendations

 

[slacktide_bitog]

I want to see pics of the car

 

[skaughtz]

A cooler line flush is pretty simple, it just requires you to stay focused while you pump it out and refill it. Having a second person to turn the engine on and off while you monitor the flow is a big help. I would do that if you have no idea what is in there, plus it gives you a good start date for your own maintenance schedule.

On the other hand, if you are dropping the pan anyway you could just do a drain and fill after that with the next few oil changes and you will basically end up in the same place.

 

[CleanSump]

I always used AC Delco or Wix in the GMs I had. Turbo 400 in a LeMans was probably the closest to what you have and used Valvoline in it and later Blazer trans. Still use Valvoline Dex VI in our BMW's French made GM trans. You'll probably only save $10 by purchasing a cheap filter.

 

[Rokey199]

I want to see pics of the car

 

[Rokey199]

I always used AC Delco or Wix in the GMs I had. Turbo 400 in a LeMans was probably the closest to what you have and used Valvoline in it and later Blazer trans. Still use Valvoline Dex VI in our BMW's French made GM trans. You'll probably only save $10 by purchasing a cheap filter.

Thanks for the reply CleanSump, I will look for a Wix filter and go ahead with the Valvoline

 

[slacktide_bitog]

View attachment 323707

Nice

 

[Rokey199]

A cooler line flush is pretty simple, it just requires you to stay focused while you pump it out and refill it. Having a second person to turn the engine on and off while you monitor the flow is a big help. I would do that if you have no idea what is in there, plus it gives you a good start date for your own maintenance schedule.

On the other hand, if you are dropping the pan anyway you could just do a drain and fill after that with the next few oil changes and you will basically end up in the same place.

Thanks skaughtz, I will look into the flush procedure. Do you think it's a toss-up as far as one being better than the other? drain vs flush

 

[Rokey199]

Nice

Thanks, we're having fun with it.

 

[skaughtz]

Thanks skaughtz, I will look into the flush procedure. Do you think it's a toss-up as far as one being better than the other? drain vs flush

I have zero experience with that transmission, so just a gut feeling from me, but if you are dropping the pan anyway I would just do the drain and fills since you would have to fill it up again regardless if you did a flush (pan down -> refill -> flush, or flush -> pan down -> refill). Do another drain and fill with the next two or three oil changes... or whatever sooner interval you choose... and it is essentially all new fluid in there.

 

[CleanSump]

View attachment 323707

Beautiful!!!

 

[SammyChevelleTypeS3]

View attachment 323707

Oh boy. She is super sweet...! What a fine paint job too. I love the entire look. Appears like a light color interior?
Hood is fine too. Looks like it is slotted? What cui underneath? I would bet it is sitting there with one of the big open
element air filters? Again.... OM Goodness! Sweet stuff! Love those when they actually look like they are hauling tail when just
sitting still. ENJOY! Keep it between the ditches. I predict an award at your very first car show. Did I say how nice yet!?
Sorry, back to topic. YES - you cant go wrong flushing but draining can not hurt. I would look into some Royal Purple
Racing fluid to go back with. It is what a lot of the guys I would see at all the car shows ran in their hot rods and what
you got is HOT!

 

[CleanSump]

Sammy is in lust.

 

[SammyChevelleTypeS3]

I have zero experience with that transmission, so just a gut feeling from me, but if you are dropping the pan anyway I would just do the drain and fills since you would have to fill it up again regardless if you did a flush (pan down -> refill -> flush, or flush -> pan down -> refill). Do another drain and fill with the next two or three oil changes... or whatever sooner interval you choose... and it is essentially all new fluid in there.

That kind of thing is where my vacuum fluid pumps always came in handy. Tube thru dip stick pipe and would allow for many easy fill and drains until I felt all clear and all new inside.

 

[Rokey199]

Oh boy. She is super sweet...! What a fine paint job too. I love the entire look. Appears like a light color interior?
Hood is fine too. Looks like it is slotted? What cui underneath? I would bet it is sitting there with one of the big open
element air filters? Again.... OM Goodness! Sweet stuff! Love those when they actually look like they are hauling tail when just
sitting still. ENJOY! Keep it between the ditches. I predict an award at your very first car show. Did I say how nice yet!?
Sorry, back to topic. YES - you cant go wrong flushing but draining can not hurt. I would look into some Royal Purple
Racing fluid to go back with. It is what a lot of the guys I would see at all the car shows ran in their hot rods and what
you got is HOT!

Sammy, yes it has a light tan interior, louvered hood, 3" chop, shaved handles, 38 Ford front sheet metal and the cut out running boards. Fuel injected 440hp Blueprint 383 stroker, IFS, 4 link rear, coil overs and disc brakes all around