Power Glide question!

[58impala]

Hi Guys,
My question is about a '58 cast iron power glide transmission. I need to know which of the transmission cooler lines going to the radiator is the pressure line. One line comes out of the tranny above the other line so for the sake of discussion lets call them an upper and lower liner. Which is the pressure line? Thanks for the help.

 

[58impala]

No powerglide experts

It seems there's no cast iron PG experts on here and I was hoping to save me some work. This weekend I'll pull the lines from the radiator and bag the ends and find out which is the pressure side. I'll post the results for the benefit of anyone in the future who needs the info.

 

[Ronnie Russell]

Jim, I know very little about transmissions, but I would think that the pressure would be consistant through both lines. Fluid is pumped forward , through the radiator for cooling, then loops back to trans. Very few still use the cast iron glide, so that is why you got no response. Wished I could be of more help, but that is the way I understand it.

 

[skipxt4]

Jim: I don't know if the cast iron PG is the same as the aluminum PG. But, I have a picture in a Motor's manual that shows the top line, as being the inlet line, and the bottom being the outlet line. Skip

 

[rstreet]

I have a iron PG and have never checked into the pressure lines either. Mine was rebuild in the late 80's and I haven't had to touch it because the car has only been driven 5,000 +/- miles since then. Just have to add a leak additive maybe once a year

 

[58impala]

The reason I need to know

I recently had the radiator re-cored and The guy thought he was doing me a favor by sandblasting the finished radiator just top remove some rust on the mounting brackets. You would think he would have the foresight to plug the lines to prevent sand from entering the cooler. Well you guessed wrong. When I found out what he had done I thought I should flush the trans cooler with ATF brfore connecting the hardlines, just to be on the safe side. Well I dont know how the cooler is designed but it must be more complex than just a tube because after flushing with three guarts of ATF and still getting grit out of the cooler I needed a solution to prevent trans damange. I decided on a trans filter which I hope will do the job, I hate to think I'll have to buy a new radiator after over $300 for the recore. Since the remote mount filter has an inlet and outlet and a spin-on type filter, for purposes of the filter doing it's job, that's why I needed to know which was the pressure line. You know Murph'y law has a way of jumping up and slapping you in the face, if it can happen it will. How much grit does it take to cause problems in and automatic trans. You guessed it.........one grain. If you want it done right ...... do it yourself is the moral of the story.

 

[skipxt4]

Jim: You may want to try laying the radiator down flat, and filling up the tank with lacquer thinner. Slosh it around, drain it out and use compressed air to blow it out. Do this a few times. Trying to remove sand with ATF is not gonna work. Skip

 

[chevymusclecars]

Jim

I looked in the factory service manual and they do not say which line is the pressure side because all test are done from pressure points that have plugs in them that you remove for the test. You are doing the right thing by holding the lines over a bucket and see which one has flow, that will of course be the pressure side. The heat exchanger is simply a coil of line running through the lower tank and should be easily flushed clean.

Bill

 

[rstreet]

Jim:
skipxt4 is right for a different reason. While we are thinking which line is the pressure line for "pumping" out your sand the viscosity of the atf and the pumping rate of the pump probably won't be enough to keep the sand in suspension to moving it out.(basic stuff as to how our municipal sewer systems are designed) The lacquer thinner is less dense and the air will be of a velocity to get the junk out then the thinner will evaporate in the coils
maybe skipxt4 will be available when we have our next job opening here.... just pure genius

 

[58impala]

The remote filter I purchased from Summit uses a spin on type filter and I already have it mounted and ready to connect between the radiator cooler and the return back to the tranny. I'm confident it will catch any remaining grit and prevent it from getting back to the trans. I agree the lacquer thinner and air pressure sounds like it might work but the filter has to be sure fire. Thanks for all the input and suggestions. When I find out which is the pressure side I'll post the info in a new thread. Merry Christmas and happy holidays to all.

 

[skipxt4]

rstreet: Thanks for the vote of confidence Bob. But far from a genius. Please don't let my wife know about a job opening, she's looking to get rid of me for four hours a day, now. She say's I have too much time on my hands. Skip

 

[oldskydog]

Jim,
I have a 58 Biscayne with the original engine and PG . I will look at it tomorrow and post back which line goes where. I went through this question about 2 years ago and discovered that the service manual and asembly manual were no help.

 

[mpris]

According to this website, on all chevy transmissions the pressure line is the bottom line and the return is the upper.

www.racewithjw.com/techNotes.php

Poocho