90 Suburban TH400 Trans Cooling Line Replacement

[Bright Idea]

I need to replace the trans cooling lines on a 1990 GMC V2500 Suburban. Are stock hard lines available ? Is there a flexible alternative that works well ? Not concerned about keeping it original, just running. Thanks in advance.

 

[Matt69olds]

Inline Tube more than likely has reproduction steel lines.

Any shop that makes hydraulic hose could make lines. You could also use AN fittings.

Keep in mind, the fittings that thread into the transmission case are NOT tapered pipe thread. The factory used fittings with copper washers. While tapered pipe fittings will fit, it’s very easy to crack the case if you over tighten the fittings.

 

[Bright Idea]

Inline Tube is where I went. Bought a stainless set for about $ 120 shipped. They fit like a glove, a bit of a challenge to thread them thru and around the cross member and radiator hose. These particular lines were flared fittings both ends. Inline looks to be a good source for OEM tubing needs.

 

[Scruffy49]

Have a set of braided stainless AN lines to go in our 85 C10. As soon as the 4.3 gets 350 swapped, and the single row aluminum with plastic end tanks crossflow radiator gets 4 row copper/brass swapped. Going to swap oil cooler and power steering cooler lines to braided stainless AN type as well. The replacement big block radiator is a lot larger than the 6 cylinder version, hard lines won’t straight swap over.