Transmission cooler line leak

UncleFrank · January 15, 2019

Hey guys, just bought a 2005 2500hd 6.0 from a local dealer. I started to undercoat with fluid film this weekend and noticed a leak coming from one of the lines under the front right corner of the truck. I think its one of the transmission cooler lines. It looks like its leaking from the crimp. Ive attached pictures. What am I looking at here? Any input would be really helpful. Thanks in advance!

davester · January 15, 2019

Yeah, very common problem with all the lines (oil, transmission fluid, power steering fluid) that use those crimps.

I've replaced all of them. It's a dirty job, but not particularly hard (worst are installing the transmission lines, as there a bunch of stuff to route the lines around). Don't forget to buy the little clips for holding the lines into the transmission & radiator, as you shouldn't re-use them.

mattchrz · January 22, 2019

you don't happen to have the oem numbers for the hoses you replaced. i'm looking for the numbers to and from the cooler and anything else need to repair all the trans lines and oil cooler lines. (also replacing power steering lines in the spring) 05 silverado 2500 hd, trans 4L80E (79,000 miles) base, rear (two)wheel drive. bought new. looked on amazon, acdelco site, rock auto and gmc parts....coming up with different numbers (15809057, 15812029, 15267484)... any help would be appreciated!!

thanks,

matt

davester · January 22, 2019

look through the RPO codes listed in the glovebox, and decode them. There should be one for the transmission (or maybe not). The right lines depends on what options your truck was built with.

For my truck, it has RPO code "KNP", decoded to COOLING SYSTEM TRANS, HD, which indicated which were the proper lines to buy on rockauto.com for it.