Tranny cooler lines

[g-money]

Can I use rubber fuel line for the tranny cooler lines or does it need to be steel with compression fittings? Are the tranny cooler line under any pressure?

Thanks<
Galen

 

[Fathom]

Well my 2000 F350 uses rubber lines and those spring clamps!

So I say just use rubber and clamp them down

Good Luck

Fathom

 

[75]

its a low pressure system so rubber is fine. gotta keep it away from heat though~bill

 

[TJK74]

I'm running rubber on mine with standard hose clamps. Been that way for over 10 year with no problems so far.

 

[Broncobowsher]

You can use rubber, but get rubber tranny cooler line, not rubber fuel line. The tranny cooler line is designed for the additives and heat of the tranny cooler. Fuel line will get hard and brittle with heat. Then when you least expect it (out in the boonies 50 miles from anywhere or on the way home christmas eve when every store is closed) that rubber fuel line will break. Auto trans do not work without fluid and the remains of the hose will be too stiff to make a patch job.

Go ahead and use rubber line, just use the right line.

 

[HotWheels]

I'm using Earl's Super Sport hose and barbed fittings. I know that on the upper end the c4 works at about 240psi; so when they said dont use regular rubber hose they were spot-on. I am running the hoses from tranny-radiator-in-line-cooler-to tranny.

hth

Mick

 

[pinenuts]

Hotwheels...Wouldn't the pressure be the same everywhere in the cooler loop? It is hard to believe there is much pessure drop in the radiator.

 

[HotWheels]

Hotwheels...Wouldn't the pressure be the same everywhere in the cooler loop? It is hard to believe there is much pessure drop in the radiator.

Let me clarify. My ENTIRE tranny line setup is the Earl's Super Stock hose. I was only explaining the route it takes.

 

[Broncobowsher]

I'm using Earl's Super Sport hose and barbed fittings. I know that on the upper end the c4 works at about 240psi; so when they said dont use regular rubber hose they were spot-on. I am running the hoses from tranny-radiator-in-line-cooler-to tranny.

hth

Mick

I believe that the 240 PSI you are refering to is main line pressure, not the cooling circuit pressure. If you are running 240 PSI through your cooler, you have some SERIOUS problems. Cooler pressure is very low, if it was high then you would be seeing people blowing hose fitting off coolers all the time. I can't count the number of time I have had a radiator out and just slipped on a peice of old line (usually fuel line) with a couple of half assed hose clamps just to hold the fluid in so I can drive the car 50 or 100 feet. No was the fluid ever became warm enough to be an issue with the junk hose I was using, but I know that if the pressure was anything over 20 or 40 PSI that hose would have blown completly off.

As I stated before, just pick up some tranny cooler line from a good parts store (note that some idiots will try and sell you fuel hose for the same thing. They just don't know better). Get someone who knows what is going on or get another parts store. The right hose costs a little more then fuel hose, but will outlive it by a long shot.

I had some old fuel hose laying around that was once used to plumb a trans cooler. Was in service for 6 months and was so brittle you could shatter it by hitting a wrench against it. It would not slip off the barbed fittings, it crumbled off.

 

[HotWheels]

Ah, that is good to know. My tranny guy told me what pressure my c4 would run at. I thought that the lines would also be pressurized. Live and learn.

thanx.

 

[72bronco]

I've been running rubber tranny cooler lines for years with no problems.

 

[HotWheels]

I've been running rubber tranny cooler lines for years with no problems.

This makes me feel better. I was worried that my 250psi lines may be pushing the limits. How did everyone route their rubber lines? Did anyone have headers to contend with?

 

[Jeepster]

I just wrap them around the headers a couple of times. %)

 

[HotWheels]

I just wrap them around the headers a couple of times. %)

we can talk about this off-line if you feel it detracts from the thread. I was just looking for intelligent routes for my tranny lines. I took them to the outside of the foremost passenger side body mounts then up and over the inner fender. Thought I'd use a T-clamp to hold them to the floor board brace. Does this sound logical?

 

[72bronco]

I have full-length headers and am able to route the tranny lines away from them with no problems. Mine just run along the frame rail to a tranny cooler mounted in front of the radiator.

 

[HotWheels]

I have full-length headers and am able to route the tranny lines away from them with no problems. Mine just run along the frame rail to a tranny cooler mounted in front of the radiator.

I guess the biggest problem was that I have a external cooler with fan mounted on the passenger inner fender. I have another set of eyes checking the routing; so I hope we have it right. thank you.

 

[Broncobowsher]

When I did the automatic conversion I was running long tube headers. I found it easier to just route the cooler lines up the back of the transmission (following the dipstick) and across the top of the intake. Those were steel and rubber ran from the top of the intake to the coolers in the rad and grill.
Current set up is manifolds (K-code) and frame rail routed stainless line. Short rubber lines from the trans to the frame for flex. More rubber lines from the stainless lines to the coolers in the rad and grill.

 

[HotWheels]

When I did the automatic conversion I was running long tube headers. I found it easier to just route the cooler lines up the back of the transmission (following the dipstick) and across the top of the intake. Those were steel and rubber ran from the top of the intake to the coolers in the rad and grill.

Yeah I thought about that too. I think this setup will have to do. I have my aux cooler on the inner fender. thank for the ideas though. at least im not so concerned about the pressure anymore. where is this "main line" that gets upto 240 psi anyhow?

 

[Broncobowsher]

The main line pressure is one of the many circuits inside the transmission. Main line is because it feeds all the other circuits (or at least many of them). As main line pressure increases, so does the holding power of the clutch packs. Higher pressure also causes them to engage harder. The higher pressure works the oil pump more, eats more fuel, puts more heat in the trans fluid. Way too much can actually blow part up. So it is a balance between enough for good clutch holding and light enough for comfortable shifts. There are also other circuits for governer pressure and other things. 240 for a max PSI in a trans is actually a bit low. I often see them up around 380 and sometimes over 500 in certian conditions. These are not always the C4, but many differnt transmissions. I have also seen main line pressures in the 30 to 80 range at idle. A friend running a race glide has seen 800 PSI in his. Keep in mind that these are all internial pressures. The cooler circuit is basicly a drain for the hot oil that comes out of the torque convertor. The engineers back in the day decided to do something with this return oil and dump it into the back of the C4 for rear lube. I am sure that this was easier then trying to find room to add another circuit to the maze of plumbing in the valve body to provide that rear lube.

This is a very basic collection of auto trans information. There are many differences in different transmission even among the same manufacturer. I have a good college class on auto trans design and the lab included a rebuild of a C4 and running it on a trans dyno. Mine was the only one in the class to work the first try!

 

[HotWheels]

BB,

Very informative, thank you. So what do you think the line pressure is?

Another question: My tranny guy said to run type-f in my tranny since it was built for it. Do you hold to this also or is it ok after a rebuild to switch?

thanx again.