Doug, I currently have 2 heaters sitting on a shelf (STILL yet to be installed......maybe this year) interestingly one is for DS install (ordered for a 96 lexi) and one is for PS install (ordered for my 93) the brass heater on both is the same, the diff is the elctrical cord config and stamped temp rating on the cord itself. again there is no difference in the actual brass heater plug. I will have a look at the Orings in each to see if I can see a difference.
O rings are normally used for applications where they are under pressure and fixed in place, I believe. E.g. better in a groove, not just floating around under a flange. A gasket is better for the latter probably. Is that possibly an issue here? Where is this Oring fitted?
IIRC, the O ring is trapped in between the outer flange of the unit, and a smaller flange. When you push the unit into the freeze plug hole (which has a chamfered edge that helps the O ring squeeze in), the O ring is then trapped between the heater body and the freeze plug hole. When they come out, the O ring has been changed into a square cross section though obviously it went in as a round cross section.
What I've done is ordered a couple $6 freeze plugs I can install if this goes sideways. When they come in, I'll pick a day to do the coolant flush, finishing with the block warm and empty and an empty hole in it which I'll clean up carefully. Then if the wings look usable I'll cruise around town looking at O rings of Nitrile that will fit. When I install, I might put a thin layer in the hole to bond the O ring to the hole, then more behind the main flange as it mates full home. Some gush around all edges ti indicate proper coverage without gaps and I'm done Let all that slightly squishy stuff dry slightley. then tighten up the big bolt that mashes it
I had a look at the Orings on both heaters I have and they are both the same (orange soft compound) they both come with a small packet of silicone grease for pre-lubricating the Oring stuck to a card that says
WARNING
1.pre-lubricate the main oring using the enclosed silicone grease packet only.
2. Do not use petroleum based grease or oil.
3. Do not overtorque. Max 19 in.lb.
I had a look at the Orings on both heaters I have and they are both the same (orange soft compound) they both come with a small packet of silicone grease for pre-lubricating the Oring stuck to a card that says
WARNING
1.pre-lubricate the main oring using the enclosed silicone grease packet only.
2. Do not use petroleum based grease or oil.
3. Do not overtorque. Max 19 in.lb.
I've found some cryptic notes tucked into the FSM regarding an O ring measurement. Could you see if these correspond to your O rings? I suspect I measured the last one I installed because I saw the trend with the O rings deteriorating, but having you roughly measure yours and agree these are close will give me the confidence to order some.
OD - 1.39"
ID - 1.18"
Dial caliper of thickness of the round O ring's cross section: .104
I realize these don't add up (they should), and suspect the cross section measurement was easy to get accurate, where the flexy O ring doesn't lend itself to accurate measurement on a caliper. So, if these seem very close to yours, or you can get an accurate measurement of yours then I'll order some to have on hand ASAP.
Orings should last a long time, not just a couple of years.
