Transmission Oil LInes

[dnwong]

Hi, my 95 Chev Astro just started leaking oil from the transmission oil cooler lines.

How hard is it to replace? Does anything have to come out or can I route the lines pretty easily?

thanks,

[MountainManJoe]

Where does it leak? Can you post any photos?

[dnwong]

Where does it leak? Can you post any photos?

There is some rust on the lines itself where it is attached to the frame. The leak is coming from the lines. So, I figured I need to replace them.

[MountainManJoe]

Are you sure it's rust? My lines are aluminum.

Anyway, you could snip that part off and clamp some rubber hose on and not have to worry about removing anything.

[1Gary]

Awhile ago I had to replace the good Gates rubber hose lines on both the RV and on the LT for the trans coolers.I ran into the Gates rep at the parts store and had one of the cracked hoses with me.The long and short of it I was told all hose companies had to change the materials to provide a better price point.The bottom line is the quality isn't what it used to be.The fuel injection rubber line has more nylon in it and is less likely to crack due to heat.I was later talking to a fiend of mine who owns a tranny shop and he told me the same thing,that they have seen the same thing with the common rubber hoses.

[dnwong]

Are you sure it's rust? My lines are aluminum.

Anyway, you could snip that part off and clamp some rubber hose on and not have to worry about removing anything.

Mine looked alluminum too. However, when I went to get the trans flushed at a trans shop, that was what they identified as the problem. hmm...

[97CargoCrawler]

I think the lines are aluminum. I removed mine a few months ago and it was a major PITA. I had to tweak the lines a little bit to get them out.

As far as snipping the line and adding in a length of rubber hose..... you're asking for trouble. I strongly suggest that you have rubber extend several inches past the cut on both sides, use very tight fitting hose and use two high quality constant pressure hose clamps per side. DO NOT USE WORM DRIVE CLAMPS!

The reason I know this is rather embarrassing so I won't go into it. Let just say I lost about 5 quarts of tranny fluid on the highway because one of those cheap ass Chinese made worm drive clamps failed 20 minutes after I installed it. The rubber hose shot off the barbed part of the cooler line. I had replaced the rubber portion of the line by cutting off the crimped sections prior to the failure. I had double clamps on each end of the replacement hose and the pipe was barbed and it still shot off and spurted tranny fluid right onto the exhaust manifold. So imagine sliding hose onto a slick (non-barbed) section of pipe. That oil gets really hot and expands the rubber. It has to be sealed really tight.

The hose needs to be snug on its own too otherwise the pipe will easily deform from the hose clamp pressure. It's tricky. If you look at a secondary oil cooler input and output pipes you'll see that most have about 2" of barbed pipe. It's necessary to keep those hoses from shooting off under pressure.

Anyway, I ended up using constant pressure clamps made in Switzerland. No problems since.

[MountainManJoe]

I've used screw clamps successfully for coolant, transmission and oil lines. Avoid the garden-variety kind. They are usually narrower and made of softer metal that easily deforms. Use automotive application ones. The key is to get the proper size. If they're too big, they won't seal properly. Like CC said, make sure there is enough overlap. If you can, make a flare in the end of the Al line.

[dnwong]

I've used screw clamps successfully for coolant, transmission and oil lines. Avoid the garden-variety kind. They are usually narrower and made of softer metal that easily deforms. Use automotive application ones. The key is to get the proper size. If they're too big, they won't seal properly. Like CC said, make sure there is enough overlap. If you can, make a flare in the end of the Al line.

This sounds like a better solution that tearing the hoses out. I guess we are using a fuel line grade hose. Is it a 5/16" line hose? Thanks.

[1Gary]

Sorry if I mis-stated that.It is fuel injection rubber hose line.

[97CargoCrawler]

Don't use anything but GATES TRANSMISSION COOLER HOSE. Make sure it says that on the hose. Anything less and you'll kick yourself in the ass.

I think it might be 3/8". Use 5/16" if you can slide it on. Not sure if gates makes that size hose for tranny use though. Fuel hose it NOT good enough.

[dnwong]

I can buy a replacement hose on ebay for about $21.00. Anyone know how hard it is to replace?

http://www.ebay.com/itm/180693180185?ss ... 1423.l2649

[1Gary]

Opps-Here ya go.

http://www.autozone.com/autozone/access ... 4294818780

Now would be a very good time to add a external tranny cooler while you at it.All Astro's benefit from them and come highly recommended.

[1Gary]

BTW-if you decide to add a cooler.Do not use the threw rad zip ties.The vibration of them against the tubes in the rad has a high potential of creating a leak in the rad and also there are some heat transfer that occurs between the rad and external cooler so to take full advantage of the extra cooler you much better off to zip tie alittle away from the rad like the lower pc's of the structure of the hood latch as a example.

And again,those lines failure could cost you a bunch of money.Such a cheap important part dictates any thing but a Ebay purchase.

[1Gary]

As I think more about this.You could take out your old lines(there is a spring clip I think in the middle.No big deal.)and lay them out on the ground.Get a cheap HF flanger and bender and copy your old lines with the pc of aluminum tubing.Those are single flair flanges and are not hard to do.