How to: factory auxiliary trans cooler upgrade

[thisoldcamper]

I bought the Hayden rapid cool 677 to add to my 1988 because it didn’t have an aux cooler. My campers are all less than 2500# so this sized cooler will be plenty big for me, and a definite improvement over what was stock. I’m also going to backflush the radiator cooler with some LubeGard Kooler Kleen, and finally, I’m adding a Magnefine inline transmission filter between the radiator cooler and the aux cooler. The Hayden kit came with the fitting to hook up to my stock radiator cooler.

When I had the grill off, I noticed that I had a power steering fluid cooler – didn’t know that was behind the grill.

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[Charlton]

Great write up! Got mine ordered! Actually already had the B&M 70268 but sent it back to exchange for 70266.

 

[jollyjerry]

Archived this in http://wikiwrench.com/index.php/1988-1998_Chevrolet_CK_Auxiliary_Transmission_Cooler_Upgrade in case the images go down.

Great post. I don't tow anything, but I'd be interested to my current trans temperatures with the factory cooler I have. The previous owner had the transmission rebuilt 30k miles ago, but he towed above the truck's rating (ended up getting a 1 ton truck after selling me his truck). Fluid looks and smells good, but definitely going to be careful with it and do a preventative drain and replace with a new trans filter as insurance.

 

[Kevinshelton19]

Did the swap a week or so ago, went pretty easy except for one of the cooler lines didn't want to come out. Gonna be towing a 7500lb trailer in a couple weeks, hopefully the cooler helps

 

[df2x4]

Just a heads up for anyone reading this, I've found an alternative part for the B&M coolers mentioned here that's quite a bit cheaper. Tru-Cool M7B. Appears to be the exact same unit as the black finished B&M 70266, but for about half the price.

 

[Tiny Trucker]

Was the factory oil cooler an option? I am gutted, I bought the b&m cooler, adapters, and sealant a couple of months ago, took my grille off yesterday to install, and low an behold there is no factory cooler there... just the coolant and a/c radiator.

 

[df2x4]

Was the factory oil cooler an option? I am gutted, I bought the b&m cooler, adapters, and sealant a couple of months ago, took my grille off yesterday to install, and low an behold there is no factory cooler there... just the coolant and a/c radiator.

Yes, the aux trans cooler was optional.

 

[Tiny Trucker]

Thanks man. Looks like I will have to find some fittings, fab some brackets and run some rubber lines. I assume I can just bypass the radiator cooler (warmer) and run those lines to to the aux cooler, similar to thisoldcamper above?

 

[df2x4]

You certainly could bypass the factory cooler in the radiator, but I'm actually going to hook mine back up in the process of my 4L80E swap in addition to adding the Tru-Cool M7B. Reason being is that it gets pretty cold here in the winter and I don't want my trans taking forever to warm up. I'm of the belief that leaving it hooked up is probably beneficial.

 

[Tiny Trucker]

It just means I can pinch the lines from that instead of running two sets. It doesn't get that cold here, between 1-3 degrees Celsius in the early hours of a mid winter morning and then peaks around 10 during the day. We don't get snow etc where I am.