700R4 Transmission Cooler 1981-1986, new and ready to install. Fits the 700R4. Ships fast from the USA.
Red fluid dripping off the frame rail, rust scale on the cooler tubes, or a line that split where it rubbed the crossmember on your square-body 4x4? This is a pre-bent replacement transmission cooler line set for 1981-1987 Chevrolet K10/K20 and GMC K1500/K2500 4x4 trucks with the 700R4. It is the Fine Lines TTC8107OM kit: mild steel tubing with a Galfan coating, bent to the factory routing and flared with the correct threaded fittings already on, so you are not bending tube on the driveway.
A 700R4 sends converter oil out of the case, forward to the cooler built into the radiator tank, and back to the transmission, where the returning oil feeds the lube circuit for the bushings and gear train. That means the cooler lines carry more than heat. If a line leaks, the level drops and the pump starts pulling air; if a line is kinked or crushed, the cooler and the lube circuit both starve. On these trucks the lines run a long way along the frame, through road salt and mud, which is why rusted-through lines are such a common repair on 30 to 40 year old K-series pickups.
Clean the lines with brake cleaner, run the engine in Park and follow them by hand from the radiator to the case, looking for wet spots and pinholes. Flex any section that looks swollen; rusted tube will crack or flake. If the fluid level keeps falling and the engagement is getting slow, our 700R4 delayed engagement guide walks through low level and pump prime first. If the fluid is dark and burnt, check the transmission itself before you trust it with new lines.
The maker lists this kit for 1981-1987 Chevy K10 and K20 and GMC K1500 and K2500 4x4 trucks equipped with the 700R4; our listing covers 1981-1986 of that range. It is a 4x4 routing, so it is not meant for two-wheel-drive C-series trucks. GM introduced the 700R4 for the 1982 model year, so a 1981 truck will only need this if it has been converted to a 700R4. Swapped trucks, aftermarket radiators and auxiliary coolers can all change the line ends, so compare the fittings on your truck before you install. When in doubt, send us the year, the model and the VIN and we will check it. Other parts for this transmission are on our 700R4 parts page.
Our 700R4 cooler line replacement guide covers routing and fittings step by step. If the leak ran the unit low long enough to hurt the shift quality, a 700R4 shift kit or a reconditioned 1982-1986 700R4 valve body is the next place to look.
| Fits | 700R4 1981-1986 |
| Part type | Transmission Cooler |
| Condition | New |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
No. This kit is built to the 4x4 K10/K20 and K1500/K2500 routing. Two-wheel-drive trucks route the lines differently.
It is the pre-bent steel cooler line set that runs between the 700R4 and the cooler in the radiator. It does not include a radiator or an auxiliary cooler.
Mild steel with a Galfan coating for corrosion protection, pre-bent and flared with threaded fittings installed.
The 700R4 arrived for the 1982 model year, so a 1981 truck would only use these if it has been swapped to a 700R4. Swaps can change the case fittings, so send us your details first.
Dexron ATF. Current Dexron-VI is backward compatible with the older Dexron grades the 700R4 originally used. Check the level hot in Park.
A set of flare-nut wrenches is the main one. They grip the tube nuts on more sides and keep you from rounding the old fittings.
