Help! Oil cooler pipe

[English Guy]

Hi, can someone tell me if the auto transmission cooler system on a stock 89 c4 is pressurised? Big car show on tomorrow:W:W:W and need to know if I need pipe to the radiator made up with hydraulic fittings like the original. Any advice appreciated guys, thanks.

 

[joe paco]

Hi, can someone tell me if the auto transmission cooler system on a stock 89 c4 is pressurised? Big car show on tomorrow:W:W:W and need to know if I need pipe to the radiator made up with hydraulic fittings like the original. Any advice appreciated guys, thanks.

English Guy:
If your auto has original coolant lines? If it does, the lines are filled with fluid, also under pressure when engine is running, from the trans pump, not from the radiator tank.

I may be missing something. The need for the pipes goes beyond a car show, no?

saludos, joe

 

[boomdriver]

Yes, the lines from the trans to the radiator ARE pressurized and there can be surges up to 200 lbs and beyond depending on the work the trans is doing. Usually upshifting builds the highest pressure surges in the cooler system.

You CAN use trans hose (special hose for trans fluids) to make a coupling and it will stay as long as the ends of the steel tube are flared somewhat or barbed. Double clamp these places where hose slips over steel tubing. If you use any length of hose, more than just a connection, run it thru a section of heater hose for protection againt rubbing on things, or you can place short sections of heater hose around the trans line where it does rub on something. I "double bag" all of them.

I had to use quite a bit of tran hose to make the connections to my trans cooler that I installed in front of the a/c condensor. I pulled one of the steel lines and added hose, ran it to the front of the car, thru the cooler then back to the return line. My cooler goes from trans to radiator to cooler to trans. That way I only have to make one connection if anything were to happen.

Be sure to ask for trans fluid hose. Plain heater hose or other rubber won't hold up to the pressure or the trans fluid. They sell adaptors for cooler kits that have fitting for hose and/or fitting to go into the radiator for a hose to couple to.

 

[English Guy]

Thanks for the info guys, now I know what kind of pressure we're talking about here I will rest the car up till I can do a proper fix and not a temp one just for the weekend. I'm really glad I got on here to get a more know-how opinion than to blow up the transmission:ugh, I'll still be going with my wife to the show at knebworth, just in her honda civic lol. Have a good weekend you two and thanks again.

 

[English Guy]

Hi, Boomdriver could you please tell me the size of the hose adaptor that screws into the radiator oil cooler i think it might be 3/8??
Like when you fitted your cooler I want to use a length of hydraulic hose and barbed connectors, the problem is, I had to cut steel pipe(see pics)because when I undid the pipe/rad connector (which I could'nt see) the pipe was twisting up due to it being seized solid:ugh. Is there some sort of connector that would go on the cut bottom pipe that would let me then connect some hyraulic hose on there and connect it up with some good hose clips? Sorry it's a bit long winded but i've been trying to get parts to fix this but I'm not even sure what the parts are called. Your advice would be really helpful on this, all the best Bri.

 

[boomdriver]

Hi, Boomdriver could you please tell me the size of the hose adaptor that screws into the radiator oil cooler i think it might be 3/8??
Like when you fitted your cooler I want to use a length of hydraulic hose and barbed connectors, the problem is, I had to cut steel pipe(see pics)because when I undid the pipe/rad connector (which I could'nt see) the pipe was twisting up due to it being seized solid:ugh. Is there some sort of connector that would go on the cut bottom pipe that would let me then connect some hyraulic hose on there and connect it up with some good hose clips? Sorry it's a bit long winded but i've been trying to get parts to fix this but I'm not even sure what the parts are called. Your advice would be really helpful on this, all the best Bri.

View attachment 4175View attachment 4174

No worries, glad to help...

3/8 sounds right but I would'nt swear to that. Seems like I had the same question and the answer was a standard size fitting, 3/8 I THINK....it's only been a yr, but I'm over 40 (> than a cpl over) and yesterday is a blur. I need a photo album to be certain about things from a yr ago !

What you're doing is basically what I did, but I had an adaptor that fit on the steel tube to the flare, for a hose to fit on. You can semi flare that end and work a hose on at least 2-3cm with 2 good screw clamps behind the flare/barb end. That steel tube is soft steel so it flares easily. The brake tubing is another story...

I believe I bought the barbed fitting for the radiator from a hardware store, brass, got the special trans fluid hose at the auto parts house with the clamps.

I have another fitting in my box somewhere, and if I can find it I'll check it and post the size, for sure.

UPDATE:
I looked for that extra fitting but was unable to find it. When in doubt, buy a size under and over so the bases are covered. Take the old piece with you to match the threads. Returns give you an excuse to go back and shop for something that you really want...

Good Luck