Removed the PS pump and steering shaft and knocked off the oil cooler. As was mentioned before it's a mess. Have a few buckets ready to try to catch the flood. Recommend you remove the rear header bolts first from underneath place a bucket under the rear header and then move to the front header which you can reach from the top. Have another bucket under the front header. If you are working on a concrete floor have the floor squeegee ready. Then from the top front break the bundle away from the block. Do not do this from under the vehicle unless you're craving a coolant and oil shower. Caught the majority of the sploosh in the buckets and then moved them to catch the run off drips after the deluge. Good to have some cardboard under there too to help keep it orderly. Then grab the squeegee and rake some coolant out the door! A hose handy to finish the pre clean up. I'm done today. Gonna let it drip for a day or two. Definitely drain your oil if you want to save it. There will definitely be some coolant going into the oil pan. Leave the plug out.

 

WC, you recommended high tack for the gaskets. I see that russrepair.com says spray high tack on the block side and Aviation Sealer on the header side of the gasket.

For gasket dressing I usually use Permatex #2 and apply a thin layer on both sides of each sealing face, so both halves to be joined and both sides of the gasket.

The spray high tack seems to me to be difficult to apply to the block surface without some over spray. Can plug the block holes when spraying there. Then I assume spray the gasket and stick it into position on the block. That way you are not knocking the gasket off the header when snaking it into position. Then the aviation sealer can be applied to the outside of the mounted gasket and a thin amount on the headers while just off and near the block. I was thinking of using high tack brush on instead of spray. Get some Aviation sealer brush on for the gasket to header sides.

The diesel hub guy says RTV, and Russ says never use RTV of any kind.

Assembly lube is vasolene, grease, and others mentioned as well.

WC which lube and gasket dressing do you use?

All others please inform how you assembled and installed your oil coolers.

Thanks,
BB2

 

For o-ring lubricant I'm planning on using permatex o-ring lubricant:

https://www.permatex.com/products/lu...ubricant-1-oz/

Any comments?

 

I use the Hi-Tack that brushes on--a little goes a long way. I can't recall for sure as it was 8 years ago, but I likely used the Avaiation Gasket maker no.3 as that's what I keep around. Permatex does list another gasket sealer, Super300, that specifically resists antifreeze & oil but I've never used it. I used Amsoil Assembly Lube on the o-rings and to lubricate the headers a bit to help reassembly, so I guess I used "Reassembly Lube". I'm not sure about the Red Anaerobic as I've never used it. Permatex doesn't list a "red" anaerobic other than some have red caps on the tube. Both anaerobic gasket maker and flange sealant are listed. The flange sealant claims to fill up to .020 gaps and the gasket maker up to .015. I see that Russ did list the spray Hi-Tack but I can't see that being a problem--just hold the gasket and spray one side. He's not suggesting spraying the block with Hi-Tack. As I write this I think I'm seeing why Russ recommends High-Tack on the block side--it leaves a tacky surface and will be less likely to allow movement of the gasket.


When I first started teaching myself automotive repair with the help of many forum posts one of my early mistakes was using a hair too much RTV when replacing the water pump and sure enough within the first week I noticed a pinhole, teeny tiny leak that of course required doing everything over again. I'm fairly sure that the RTV allowed/caused the gasket to move slightly when the flange was compressed against the block, and I am sure I obviously used too much RV if that happened and undoubtedly many people have used a fine film of RTV with zero issues. I know there's nothing wrong with RTV but I do use it sparingly and only when it is the absolute #1 recommended sealant or dressing. I'm not a professional so I try to do what I can to tilt the odds in my favor. But, do the same repair twice in one week and you will get pretty familiar with the process.

And again I'll mention that it doesn't have to take a ton of force to reassemble the headers on to the tube. I did mine using my stomach on one end with other pressed up against the side of my flatbed. If your tube is all rusty and pitted then it might be a different story, but not much rust out where I live. Maybe sandpaper to clean up the tube exterior if it's real bad?

 

I have always coated all faces joined with gaskets. A light coating on each face ensures an even seal. I don't like the idea of spraying the gasket only and then applying it to the block. I'm going to use high tack brush on and coat the block and the gasket and stick the gasket on. Then apply a thin coat of aviation sealer to the mounted gasket. Then get the cooler up close to the block and apply a coat of aviation sealer to the cooler headers then bolt it all together.

The permatex o-ring lubricant says it resists automotive fluids, protects all types of rubber O-rings, helps seal the o-rings. Good for high temperatures. A side benefit is it's food grade so I can use it on valves and faucets as well.

We're in for a winter blast of cold and snow. It might be a while for me to get motivated to finish up right away. I still need to get the cooler out of it's resting spot off the block and finish wiping up some of the sploosh remnants. I'm going to try to get that far today.

 

Cooler was extracted today. I didn't have to jack up the engine but I did remove the bolts to the proportioning valve bracket. Then I tapped in a wooden wedge between the bracket and the frame. This moved the valve back a smidge and out a smidge allowing the front header to squeeze by. I tapped it in a bit, check for interference, and then tap a lil more. Try and see if you can get past. I tried three times with three taps and that did it. Glad because I ran out of room for one more!

 

I'm no expert but I think the idea from Russ was that the High-Tack helps hold the gasket in place once it touches the block and the Aviation No.3 or anaerobic creates a flexible seal on the header side--I did the reverse with Hiigh-Tack on the header side and Aviation on the block side. I think it would be hard to place the gasket on the block and then get the header to line up to it but that's just me. What I mostly remember about doing this was having the assembly supported in one hand while I contorted myself into position and managed to get a couple bolts in to take some of the strain off my arm. I'm pretty sure I would have bungled one or both gaskets if they were not already held in place on the headers. This is all good food for thought as I need to do this repair to my 1990 ASAP but have been so busy with work I barely have any time to work on the truck.

 

This is my first oil cooler. So sharing ideas is great. I wouldn't have gotten half done without the help!...

my plan is coat the block with high tack. Coat the gaskets with high tack and stick them on the block. I'll align the holes with one of the bolts or a tapered pin to get the gaskets on there good and straight on. Then with header close to home coat the gaskets on the block and the headers with Aviation sealer #3. Now I'll be working alone so I'll try to get one of the long bolts started up top front then go below and get the bottom rear bolt started. Then work those two till up close to the gaskets then finger in the rest. Then tighten one front bolt then one bottom bolt then each header crossing pattern to torque level.

My header bolts weren't real tight when removing it. I think diesel hub guy listed a torque. It's not alot. I'll review that later...

Interesting but my original assembly appears to be a thin line of RTV. I only have used RTV on gasketless joints, like my lawnmower transaxle.

 

Pulled the headers off my cooler today. The bundle looks great. It was not acting as a filter as some of the youtube videos I watched showed the intake side of the bundle had crap blocking some of the tubes. I was unable to tell which end the flow of coolant goes through first. All tubes clean as a whistle. I reamed them any way even though they were all clear. No coolant and oil mixing so the little o-ring on the ends were good. Only the front header leaked oil externally. The o-rings were all intact and looked a little hardened but no cracks. So I'm glad to get it renewed with only an external leak. I'm going to put a generous coat of o-ring lube on all the new ones. I am amazed at how good the internal seats and bundle look. Minimal clean up needed and reassemble next.

 

When I did mine on the '92 with 310k or so on it the cooler was very clean inside and no blocked tubes, but the o-rings were so brittle they cracked into pieces just lookin' at 'em.

 

I got my rebuild kit today. 4 O-rings. Check. Three gaskets! I was expecting two. One of the gaskets only has three bolt holes. The other two have four bolt holes. I think I read somewhere that the van 6.9l cooler was different? Maybe the three bolt hole gasket is for a van?

The gaskets have a raised line of hard rubber sealant on one side. I think that side goes to the block. I haven't compared the gaskets to the headers yet. I'm still cleaning them up getting the old gasket sealer off of them and the block.

 

If memory serves correct I put the raised rubber portion to the block. I swear I've spent more time cleaning up the mating surfaces of parts than any other aspect of repair. I'm sure there's a better way but I haven't found it.

 

I think it will be obvious which way the gasket goes on. Still wondering about the third gasket in the kit. Yes getting old cooked gasket maker off is a big job. I ordered some CRC gasket remover from commiezon thinking it gets here this week but on closer examination it's estimated arrival is next week. You can get a can at Orielly's for 7 bucks but it's snowing and I don't have transportation. So pay three times as much and wait...and wait. In the meantime I sprayed the old gaskets with all purpose spray lube/penetrant from NAPA so hopefully that will begin the softening process. I already removed the inner fender liner and next the tire is coming off as I can see that will improve access for cleaning up the block and fishing the cooler back in.

 

Definitely remove the inner fender and the tire. I read in this thread one fellow did the rear gasket removal from below. Complained about bits of gasket falling on his face. Don't do that! Remove the front tire and inner fender. It's easy.


made use of old jeans and t-shirts to wrap greasy and oily parts you reach through. Skip that if you like grease and oil coated forearms. You can see the wedge I used to ease back the proportioning valve with.


Really improves access for cleaning up the block. I stuffed bits of rag into the block openings to keep bits of gasket and gasket remover out of the block. A bit blurry photo but you can see the front and rear openings and the rag bits I stuffed in the holes.

Just about cleaned up now. A lil bit more scraping and gasket remover and I'll be ready to reassemble. Next time I'll start by removing the tire and inner fender first. Would Have Been A Lot Easier !!!

I did find a vendor on ebay that could send me the gasket remover in three days instead of waiting two weeks for amazon to deliver. They were quick to make a shipping label so I couldn't cancel the order. I guess I'm well stocked in gasket remover soon.

 

WC was asking how do you get the old gaskets off? Yes sir those header gaskets get cooked on good. Yesterday I scraped some more using a plastic scraper, small wire brush and a little bit with a steel wood chisel. I've let the gasket remover spray sit over night twice now. Then reapply before scraping the next day. I still have a couple tenacious spots left. But make progress every day as the gasket material softens and gives up ground. I don't really recommend a steel wood chisel but if you are careful you can get a layer of gasket off to where the remover spray can penetrate in further. The plastic scraper works fine once you're down to gasket dressing. The small wire brush does a good clean up job on the stickiest portions of the gasket dressing and helps score away some gasket too. I'm only working on it a few hours a day as it's freezing cold except when the sun is high. Sprayed the gasket remover one last time and done for today. Let those remaining bits soak in it. The block is clean now, just one header that has a couple clingons.