C6 Transmission Cooler Lines question

[jmcgill89]

Thanks to the experts for the advice on the oil pressure.

Now that I have the pressure gauge in there, and have most of the functional aspects of the car sorted out, I want to get to work on the transmission leak that I get when the car is running and just after it turns off.

I think I've traced the majority of the drips to the transmission cooler lines on the passenger side.

One quick question: Do the lines, as they go into the transmission, have any sort of seals or o-rings that I can replace, or is it just a straight tightening job like brake lines?

I will try to get in there and tighten them, but that's a tight fit. I may have to look into some weird bended wrenches.

Thanks,

Joe

 

[trainey]

There are no seals, or O-rings. They are a flanged pipe, similar to a brake-line. There are special wrenches to work with this type of setup, they are essentially boxed end wrenches with a slot cut to slip over the line. They get more wrench surface on the flangenut than using an open end wrench.

 

[c9zx]

There are no seals, or O-rings. They are a flanged pipe, similar to a brake-line. There are special wrenches to work with this type of setup, they are essentially boxed end wrenches with a slot cut to slip over the line. They get more wrench surface on the flangenut than using an open end wrench.

Trainey is right, you may need some line wrenches or stubby (short combination) wrenches. It is tight at the transmission end. If there are any connectors anywhere except at the trans or radiator ends, the line has been spliced and is a possible source of a leak. Changing the lines is a pain with the engine in the car but, can be done.

 

[jmcgill89]

If a quick tightening doesn't work, I'm going to get a set of flexible lines in there rather than go through the soul-crushing pain of putting in the fitted steel lines.

There is another item over there near where the lines come into the trans, looks like some kind of modulator or sensor. It may also be leaking.

I'm sort of leaning away from the filler hose leaking, because it only leaks when it's running and just AFTER the engine is turned off. It never leaks while just sitting.

There are no seals, or O-rings. They are a flanged pipe, similar to a brake-line. There are special wrenches to work with this type of setup, they are essentially boxed end wrenches with a slot cut to slip over the line. They get more wrench surface on the flangenut than using an open end wrench.

Trainey is right, you may need some line wrenches or stubby (short combination) wrenches. It is tight at the transmission end. If there are any connectors anywhere except at the trans or radiator ends, the line has been spliced and is a possible source of a leak. Changing the lines is a pain with the engine in the car but, can be done.

 

[trainey]

There are no seals, or O-rings. They are a flanged pipe, similar to a brake-line. There are special wrenches to work with this type of setup, they are essentially boxed end wrenches with a slot cut to slip over the line. They get more wrench surface on the flangenut than using an open end wrench.

Trainey is right, you may need some line wrenches or stubby (short combination) wrenches. It is tight at the transmission end. If there are any connectors anywhere except at the trans or radiator ends, the line has been spliced and is a possible source of a leak. Changing the lines is a pain with the engine in the car but, can be done.

If a quick tightening doesn't work, I'm going to get a set of flexible lines in there rather than go through the soul-crushing pain of putting in the fitted steel lines.

There is another item over there near where the lines come into the trans, looks like some kind of modulator or sensor. It may also be leaking.

I'm sort of leaning away from the filler hose leaking, because it only leaks when it's running and just AFTER the engine is turned off. It never leaks while just sitting.

There are no seals, or O-rings. They are a flanged pipe, similar to a brake-line. There are special wrenches to work with this type of setup, they are essentially boxed end wrenches with a slot cut to slip over the line. They get more wrench surface on the flangenut than using an open end wrench.

Trainey is right, you may need some line wrenches or stubby (short combination) wrenches. It is tight at the transmission end. If there are any connectors anywhere except at the trans or radiator ends, the line has been spliced and is a possible source of a leak. Changing the lines is a pain with the engine in the car but, can be done.

I bought a set of replacement lines from Year One, I had to cut both lines in two near the oil pan, then I used 2 compression fittings to put them back together. My lines had been cut at the radiator (PO had put a separate trans cooler and then rubber hosed it to the cooler only). I got rid of the external cooler, and then hooked the new lines up to the radiator. If you end up needing brass fittings, NAPA has the correct size for the lines. I think they are 5/16, which you cannot find at Home Depot type stores

 

[Bill73Ragtop]

I've never had any luck with my brake line wrenches with transmission lines in the tunnel because its just too tight. Combination of stubby open end and medium length open end wrenches using an 1/8 of a turn at a time usually is the only method. And they don't have to be really, really tight - very snug should work just fine.

And make sure you start engaging the threads by hand for at least 3 +/- turns. If you cross thread it - you're gonna leak.

 

[72HCODE]

getting at the line fitting on a C6 in the tunnel is very hard. I ended up using some crows feet wrench heads and then i cobbled an extension so i could get at the fitting.

the C6 could be leaking from a few areas. I kept having a leak from the dip stick, and the brass adapters that the trans lines attach to from the C6 case.

There is a special o-ring used on the dip stick that you can only replace from another dip stick assembly. they never stock the o-ring itself. i used a C6 ford racing dipstick just to get the o-ring, even then you may need to use sealant to keep the fluid inside the trans.

After fighting with my transmission line adapters i ended up using some sealant to stop the weeping leaks. i took the brass fittings out of the trans-case and carefully put sealant only on the last few threads to keep as much as possible out of the transmission itself. once tightened down into position and the sealant dry i then hooked up the lines again and finally after years no more leaks. sometimes you just have to use sealant. I ended up using a little on the dipstick as well even with the new seal it would still weep from time to time.

the C6 is just a pain with leaks. the aftermarket parts do not help either all those chrome dip sticks and pans are bad. The chrome acts like a Teflon layer that sealant cannot adhere to so you get leaks between the sealant and the pan surface. I spent 2 years hunting for a custom made C6 trans pan with no coating a drain plug, 2 quart extra capacity and was not coated in anything. I ended up using an off-road truck C6 pan which was awesome because it was made with a baffle and the steel was super thick to take pounding from rocks. after i bought it the manufacture stopped making them, too bad.

 

[Jasnicp]

Yes, use thread wrap or sealer. I had ordered pre-bent transmission lines for my C6 and one fit great, the other not so well and ended up with a kink and was no good. I ended up getting 5/16 brake lines and made this one myself.

I've got more than one connection for the line also... Its a total of 3 lines, the 2 shortest being at the end to the transmission and cooler. I used thread wrap on all connections and have no leak anywhere. This could be an option for you if you replace the lines.

 

[jmcgill89]

Thread wrap is even good for the transmission end?

Yes, use thread wrap or sealer. I had ordered pre-bent transmission lines for my C6 and one fit great, the other not so well and ended up with a kink and was no good. I ended up getting 5/16 brake lines and made this one myself.

I've got more than one connection for the line also... Its a total of 3 lines, the 2 shortest being at the end to the transmission and cooler. I used thread wrap on all connections and have no leak anywhere. This could be an option for you if you replace the lines.

 

[Bill73Ragtop]

Chrome pan: Tape edges and hit it with grey scuff pad where the sealant will be. Same thing with valve covers.