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951C – Radiator Head Torque Specs

jonathanks ยท 2025-05-23 00:41

Hello all. 951C-86J3065 BLUF: 1. Does anyone have a torque spec and sequence for the radiator heads? We used the standard bolt torque and stitch pattern previously but, was a best guess. Nothing we found in the book and the local CAT dealer had nothing. 2. Gasket not readily available. Could make one but, thinking that I could use a good gasket maker sealant instead (Permatex 51813). Any major issues with foregoing the gaskets? Background: Re-cored radiator last year and the lower heads started leaking after a few cycles. Bad enough to drain it to the lower head flange. Have it back out and found the aftermarket core flange face had a 1/16"+ imperfection where they brazed the head on the flange. Not 100% sure that is the culprit, but looked pretty likely. Ground it flush this time (caught the corner of the tube bundle, we'll see it that isn't susceptible to cracks later, but I digress). Looked through the forums and the books and just didn't find an answer to the torque pattern of specs. I saw a couple of general references to 16 ft-lb, but nothing I'd say had anything behind it, and not a CAT tech doc. Last time we ended up using the standard torque value out of the book for this size fastener, which i believe is 30 ft-lb. We installed last year with OEM gaskets. Since then, at least one of the gaskets has gone totally discontinued and came up empty from AMS and Offroad. Decided to go with a properly applied Permatex anaerobic gasket maker and gasket dresser. Have polished everything and have the activator spray which seems most leave out... It is supposed to be able to fill 0.050" imperfections so think it will do the trick. Although the gasket dressed with this would be even better, but I'd have to make one. Been awhile since I peened out a gasket, but I can do it. Would just have to get a good gasket material for the purpose. I'm guessing with a bit more research i can find them, but that would take a few days to get in. I'd have to leave it disassembled in the weather with a risk of it sitting for a few weeks until I can get back to it again... However, really don't want to pull this thing again... On a side note. I read and asked question about pulling the radiator. Last itme we did it by the book and pulled it up and out. Did it outside and had to rig from the lift arms. Was les than fun. this time we went the remove the whoe nost route. I think i like this way better as the access it far better. However, haven't reassembled yret so jury is still out. An interesting note on this. Inthe deal bulitins on it they show pulling the entire nose assemble out and hanging it all form the lofting bosses on the radiator head. That seems like a lot to put on those se we are rigging the nose from out. just seems like a lot of weight on head. Tearing those out ruining the head and dropping the assembly seems like a pretty definitive definition of bad day. Hope something here is useful to others and appreciate anything you all can provide on my questions.

Replies5
  1. #1jonathanks2025-05-28 13:44

    Looks like my early morning entry ended up in mass typos. I think I corrected most of it in the quote, not sure how to edit it once it's posted... Ended up getting the gaskets on order and waiting. Found the updated numbers and Offroad had everything. Should be here in a day or two. Still hoping someone has a torque spec for the radiator tanks. Looks like common wisdom from radiator shop is around 16 ft-lbs. Cat spec by the bolt size is 30 ft-lbs. That is what they got torque to previously. But, lower tank leaked, maybe overtorqued? Did not really see any pinching of the gasket though. Any advice, recommendations, and observations greatly appreciated.

  2. #2Nige2025-05-28 13:55

    Is this any use.? It says it covers all 86J-prefix machines but only gives a tightening sequence, not a torque spec.

  3. #3Dave Neubert2025-05-28 19:18

    Just use standard torque for bolt

  4. #4jonathanks2025-05-28 19:25

    Thanks Nige. That at least gives me the sequence. Not the spiral pattern I had expected, interesting. I suppose if there is no guidance, I should just use the standard bolt torque. Just seems a bit high.

  5. #5Nige2025-05-28 19:34

    What diameter are the bolts.? I can't see a standard bolt torque spec anywhere in the master document that calls for 30ft lbs. I would be interested to hear where you got that number from.