Replacing rad, tranny lines, anything else?

So I decided to replace my radiator, and combine that with some other little things I had on my list for a long time. Most importantly those sweaty tranny lines!

The XJ has a separate oil cooler riding in front of the rad. Actually, that's another question I have: should I replace the tranny cooler also while I am at it?

So here's what I make of it. From the back (tranny) there are two steel lines coming in, connecting to rubber tubing, one going into the top of the rad (inflow, right?). Then the bottom hose on the rad is rubber (return hose?) that goes into a steel line that connects to the oil cooler. Steel line coming out of oil cooler connecting through a rubber hose to the steel return line going to the back (return to tranny). Or do I have the whole thing upside down?

All the rubber hoses are wet (tranny oil), probably leaking from the connections. I think it best to just replace the whole lot of them. Reasonable thought? The connections are a mix of what seems permanent connections, quick connect (a little like the ones on the fuel lines hooking onto the injector rail), and regular hose clamps. So how do I best go about that? Can I just use regular rubber tube and hose clamps on all, or are there nicer ways to fix this? Are those permanent-looking connections easy to remove? How much pressure will be on this system when running?

Further, while I pull the radiator I was thinking also to replace the serp belt and the (missing) fan shroud.

Anything else I might wanna consider doing at the same time? (I recently replaced the exaust manifold, water pump, hoses, and t-stat; the fan clutch is still good)

Thanks for any thoughts! Sorry for the exhaustive post and the myriad of questions.

What's your purpose? Working on overheating problem? Trying to upgrade all questionable areas on a newly purchased older jeep? Or what?

Depending on your answer to the above, a couple additions come to mind - like fluids and any remaining soft parts. Why not flush and refill the PS pump? Same for tranny fluid and filter. (I presume you'll flush and refill the cooling system when doing new radiator.) Also, replace any remaining rubber parts, like all the radiator hoses. Better do the heater valve thing, too, that goes bad almost as fast as the hoses.

Oh yeah, sorry, the radiator is just old. I had another thread about that, and decided that I should replace it. The cooling works fine, just the thing looks like it could go at any time soon and I decided to replace it.

What I meant was, what are things that are efficient to do while I am doing this particular bit of surgery on the jeep (the radiator out of the way). One thing was the tranny hoses. That's my primary question about.

I did the P/S pump etc recently, flushed it replaced the hoses etc. So basically the only thing I still have oil coming out from are those tranny lines. And they aren't even dripping, just wet (no oil on the floor, ever).

Also recently did the wires, plug, cap, oil adaptor rings, and the things I listed before. Was just curious about 1) how to do those tranny lines (and just the rubber parts), and 2) other things that I should consider doing while doing the rad.

Thanks!

Sounds like you already have all the bases covered as long as you have the heater lines and radiator hoses on your list.

There is not much pressure on the tranny lines. Regular hose and clamps will do fine.

While you have the rad out, check the harmonic balancer and see if it is making any contact with the timing cover. If it is you should replace it while you're in there.

There IS transmission-specific hose available...3/8" ID. A Tru-Cool Mini MAX trans. cooler I just installed came with some 23/64" ID hose which definitely seems more durable than the 3/8 trans. line commonly available, but that stuff doesn't seem to be generally available.

You might want to use the 'fuel injector' type clamps, with solid band and compression screw/nut rather than the worm-screw type....

NON-synthetic trans. fluid... Do a search re potential problems with AW4s when syn. is used.

Full trans. flush (after pan drop and filter replacement) is simple, and quite worthwhile, by aiming disconnected trans. return line, up front, into a large basin and running the engine while diligently replacing fluid quickly as it is expelled into the basin. 12-14 quarts should give a reasonably-complete flush, a few more if you want to be real sure. Search on this also.

'Water wetter', added to the coolant, is supposed to enhance heat transfer...

Might wanna consider fan clutch while the rad is out but it's not impossible to change later with rad in. Good call on Harmonic balancer check. Easier to do with rad out.

Thanks guys, for all the great pointers. Will check the harmonic balancer for sure!

So should I also replace the tranny cooler? The whole opertion is somewhat preventive but I don't want to overdo it if not needed. Are those tranny coolers likely to fail at around the same time as the rad or are they known to far outlast them?

Thanks again!

You could always take the tranny cooler to a radiator shop and have it rotted out and flow/pressure checked.

dutchjeep said:

Thanks guys, for all the great pointers. Will check the harmonic balancer for sure!

So should I also replace the tranny cooler? The whole opertion is somewhat preventive but I don't want to overdo it if not needed. Are those tranny coolers likely to fail at around the same time as the rad or are they known to far outlast them?

Thanks again!

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Tran cooler only has oil inside so it doesn't get clogged the same way as radiator with water. Long life item.

XJXJ said:

Tran cooler only has oil inside so it doesn't get clogged the same way as radiator with water. Long life item.

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Thanks! Will leave the cooler alone!