Doing oil cooler. Is this trick legit?

Found this:

Talks about unbolting the back and leaving front bolted on, then tapping rear housing so separate it from front and you can fish it out without jacking up the motor? Is this legit, or a good way to bust my cooler. Just curious? Also, I see small square plug in front of rear assembly, and brass hex plug behind it. Are they both coolant drains? I know this has been discussed before, and I remember there was a thread with pics - but didn't need it at the time, and can't find it now.

I have never done a oil cooler, but argve gave a lot of good advice over the years.

Now having read about it.
If my cooler started leaking, I would very likely give this a try.

Also knowing if I started struggling with it, I would abandon this method.

Only the brass plugs on either side of the engine is for coolant. The smaller plugs with the square heads on the driver's side of the engine are oil galleys. I haven't tried to leave part of the oil cooler attached to the engine and I never will. It's difficult enough to get it put back together when the whole thing's out of the truck. I can't imagine how hard it would be to try to put it back together with one of the end caps bolted to the engine. My opinion is that it's not legit.

I've done two oil coolers--successfully I might add. The last time I wanted to try the method mentioned by the OP but when I got under the truck and looked around I just couldn't see it working. Both vehicles were 4x4 and I had zero problems pulling the oil cooler as a complete assembly, and I did not need to jack up the engine. It also seems that everybody does the oil cooler job just a little bit differently for some reason. I recommend the gasket and o-ring kit from Russrepair.com because the gaskets are quite a bit thicker than the Fel-Pro or other kits. Use lots of lube like assembly lube or Sil-Glyde on the o-rings during reassembly. On the last oil cooler I had to delicately remove some hardened bits of grit near the o-ring seats but the first one was all nice and smooth. On both coolers I was able to use body weight to reassemble instead of a press.

On both trucks I went in from the side for a lot of the work. I removed the P/S pump from its mounting bracket but did not disconnect any lines--not sure if I needed to do this but did it just in case I needed a little extra wiggle room. One thing I would do differently is I would definitely buy a couple studs or modify some bolts for the purpose of holding the assembly in place while getting a couple bolts threaded in. I find that holding the assembly in place with one hand while not disturbing the gaskets and threading bolts in is hard to do. I used High-Tack to glue the gaskets to the block which helped a little.

One last thing is to be sure you have drained all the oil out of the cooler before reassembly. I thought I had drained all the oil out but when I went to reinstall I noticed oil dripping out and on to the gaskets so I had to finish draining it and clean up the gaskets. Best of luck to ya'--it's a fun one!

I have a built cooler ready to go on onto my truck. I dread doing it.

Have done lots of them that way, but would not recommend someone who had never pressed one together off of the truck to do it in the truck.
It can be done quite easily in the truck with the right block of wood and prybar to get ot perfectly square and pushed together.

My advise for the least amount of mess, is to remove oil filter, and have oil cooler broke loose from the block to drain over night.

I personally would not try it this way. It took a ton of force to get the assembly pressed together, and to me that seems much easier to do outside of the engine bay.

I did mine while I was doing head gaskets though, so I haven’t had to deal with the struggle of getting it out by itself. I might have resorted to something like this if I was stuck.

However you get it out, make sure you clean out all the tubes before you re-assemble it. Mine were mostly blocked by scale buildup. I used a rifle cleaning rod/brush chucked in a cordless drill to really clean them out.

If you do end up doing it in the engine bay, I would buy a woodworking-style bar clamp in the right size and use that to squeeze them together. Something like this:

This one says it has 1000lb of clamping force, and it would keep things nice and straight. Let us know how it goes!

DirtyWood said:

I removed the P/S pump from its mounting bracket but did not disconnect any lines--not sure if I needed to do this but did it just in case I needed a little extra wiggle room.

Click to expand...

I do that plus remove the ground cable from the block right there.

Nero said:

I dread doing it.

Click to expand...

I understand that. I think the worst part is when you start the engine after this and praying that nothing will be leaking.

Hadn't fully considered what that meant going in. I was thinking I would get it out, then pull the front off and clean and assemble in the shop. But then what? I have the problem going in - so maybe it's not a clear win unless you can assemble on the truck, but I don't think I'm gonna do it that way for the first time. Thanks for the input.

One thing I noticed the last time I did one was that the shop manual said to put the o-rings in the headers as opposed to the cooler bundle. Most write-ups and online info say to first put o-rings on the cooler bundle and then press the headers on. Knock on wood I've had no problems with nicked o-rings and always installed them on the bundle first.

I’ve done 3 or 4 oil coolers successfully on different trucks now and i have always just opted to remove the exhaust manifold and removed the cooler from the front. It makes the job infinitely easier and doesn’t cost all too much to replace the gasket.

I'm afraid to touch the exaust manifold bolts (probably rusted together over 40 years). I suppose I could try to crack them loose, and if they don't budge, go with plan B. One thing I noticed is lower radiator hose seems bad, but I have the big all AC radiator which I heard is impossible to get. Are the hoses out of stock too? Do I need to convert to short wide version to get a new hose that fits?

Exhaust bolts came right out. Way easier with manifold gone. Thanks for the tip. Need to go get exhaust gasket and radiator hose. Coolant and oil.

Noticed the head gasket is seeping in the front drivers side. I really don't want to pull the head off right now. Can it run like that for some time, so long as I don't get it too hot? I suppose I have oil and coolant out of the engine, and the exhaust manifold off. Can I run it, or should I just bite the bullet and pull and reseal? Don't notice it losing coolant, so guessing it's pretty slooowww leak, but I don't drive the truck very often - just to get gravel for the road, or pick up stuff that won't fit in the car. I've heard people say retorque head bolts (to what on 6.9?), so I could try that I suppose - I could use a new valve cover gasket. I can't remember if I have to take all the rockers off (hopefully not).