Torque converter drain.

[fighterofwars]

Hey, getting ready to change the tranny oil and filter in my 87 K20 Custom Deluxe. Its got the TBI 350 and 700R4 in it. My dad says we should also drain the torque converter aswell, is there a procedure to doing this or does it drain when you take the pan off. Also, about how much do I need to put in it to fill it?

[VileZambonie]

If you want to change all of the fluid the only good way is a 16 qt flush. Most qualified and equipped shops will charge you under $150 bucks. If you drop the pan you'll change about 4.5qts of fluid. The torque converter will not be drained and cannot be drained without doing a flush. Do not attempt to drill and put in a drain plug either.

[fighterofwars]

how hard is it to do a flush?

[78 Chevyrado]

Not to jack the thread, but do th350s and/or th400s have a drain in the torque converter? 

I just did my dads f-150 and it has a drain in the TC and dang that was convenient and cheap.  He said mine (th400) might have a plug, but he's not for sure.

[Camfirchev]

No Drain plugs on GM Torque Converters. 

[78 Chevyrado]

No Drain plugs on GM Torque Converters. 

That sucks...   Thanks for the info 

[k5blazerfan]

no drain plug = less chance of it leakeing ford= censored (report) only runs downhill

[Stewart G Griffin]

i was reading in a HP th-350 book (HP books are pretty good) that you could put a drain plug in the torque converter.  But wouldn't this put the converter out of balance?

i personally don't like the idea, unless it was done by the factory, which is wasn't or professionally.

BTW, merry x-mas if it applies to you.  i haven't had a good christmas in 25yrs., so it's just another day for me.  In fact, i don't like x-mas, but that's another story.

[Stewart G Griffin]

Thanks for posting the question---i'm learning alot;  i never knew that when changing trans fluid you only get maybe 3 quarts---i always thought that you got the majority of it.

Apparently, for flushing, you probably have to bring it to a shop;  i don't know if this can be done at home, equipment availability being the main issue.

http://www.youtube.com/watch?v=FjxmlrbpjTk

http://www.youtube.com/watch?v=sNZYYDfiucI&NR=1

2) Can it be done at home if:
you connect a hose to one of the trans cooling lines going to the radiator and run the engine while adding new fluid and watch until the fluid turns new?


3) Apparently, another interesting thing about trans'ms is that if the fluid is burnt, it is not recommended to change the fluid.  Because the trans will fail soon if you do.

[VileZambonie]

how hard is it to do a flush?

You need a fluid exchanger. I use this one http://www.bgprod.com/products/transmission.html

[Stewart G Griffin]

That's what i was getting at;  How much do  these machines cost and would it be worth it considering you would only use them every 30,000 miles or so?

2) What about the idea of connecting a rubber hose to the outlet line (line that takes fluid to the cooler/radiator) putting the rubber hose in a suitable container, run the engine and slowly add new fluid until the fluid comming out of the hose looks new.  Thus, in effect, flushing out the transmission?

[zieg85]

That's what i was getting at;  How much do  these machines cost and would it be worth it considering you would only use them every 30,000 miles or so?

2) What about the idea of connecting a rubber hose to the outlet line (line that takes fluid to the cooler/radiator) putting the rubber hose in a suitable container, run the engine and slowly add new fluid until the fluid comming out of the hose looks new.  Thus, in effect, flushing out the transmission?

I was wondering the same thing.  I would imagine it would need to be running and I would think chasing the old fluid out with the new is what the machine does anyway.  You could do the same thing with a paint pressure pot holding the proper amount of fluid.  The only questions would be what line to take off to hook to what and what pressure is safe to pressurize the pressure tank without harming the transmission.  One could use a synflex hose with a valve as to see when the tank is empty.  I am sure Vile will chime in on our thoughts...