Suggestions to seal block heater into freeze plug hole?

[IdahoDoug]

I'm continuing to have trouble with the factory O ring's on the block heater breaking down after a few years, so am looking for a way to seal it into the block with out the ring. Anyone have a suggestion on what to use? I don't want to use something like an epoxy which is kinda too permanent and too difficult to get out in the event I want it out some day. But something that's basically a step below that would work.

The location is the exhaust side of the block and I don't know if that extra heat is causing the breakdown or what. It begins to seep, then I have to pull it out and get another O ring. Done with O rings. It has a mechanical holding mechanism like wings that expand inside the water jacket to physically hold the device in the freeze plug hole, so I just need to seal it against coolant pressure.

This is real time - gotta do it today. Got coolant sitting here and plan to flush and then clean the hole while the block is dry.

DougM

 

[concretejungle]

Doug,

when i hammered my freeze plug through and didn't know at the time the block heater i purchased was one size too small, i had to get another freeze plug from Mr. T. It was suggested to use a loc-tite to hold it in. I know you are asking for probably more of a sealant as the loctite was just like superglue AFAIK. But, that said, it "sealed" the new freeze plug to the block and i was told in the future i could still hammer that one thru as well if needed.

I still have it at home and can get the part number if you want to pursue.

 

[e9999]

Orings when used properly work amazingly well.
Is this a design issue or a material issue?

If the latter, maybe use a better material (high temp if that's what you are concerned about) for the Oring?

 

[concretejungle]

the loc-tite stuff i was speaking of is designed specifically for freeze plugs. I think either tools or clownmidget PMed me with the stuff way back when.

 

[IdahoDoug]

Concrete,

Dunno what others think, but my feeling is the loc tite will hold a pair of metal parts precision fit like your freeze plug or prevent threads from turning due to same tight clearances. This is a loosely held pair of surfaces that don't match well and the O ring is/was supposed to do the job of sealing by conforming to each surface at lower pressure per inch. So, using it between two surfaces with large clearances may not work. Interested in feedback on that theory.

E - I agree getting a new O ring would be best. Unfortunately, I've been here before when it last failed. Unknown O ring size, as the one in it was distorted. Nobody locally knew anything about the O rings they had in terms of durability, application, etc. Blew half a day driving all over town before ordering a new unit from Cdan and scavenging it for parts and such. Figured that would be the end of it since the first lasted over a decade. Nope. So to pull off the O ring search I'd have to take the truck apart and get the old O ring out and do the same run around town thing. If I have no luck, the truck is down until I figure out the correct adhesive to mount it. If I have no luck with that, I'm down a vehicle over a stupid little fitting.

So, I'm looking for a way to stop the madness and basically glue the brass flanged thing into the cast iron hole. Hopefully, the wings that hold it in won't have disintegrated like the last time. If that's the case, then I guess I'm hosed and I guess I should have a freeze plug on hand. Crap. Anyhow - any help on the freeze plug part number would be good too, I guess.

It's an annoying situation and I'm looking for a solution.

DougM

 

[arndog123]

I'd like to find a solution also. I've had to change out the block heater o-rings on both my '85 and '86 trucks.

 

[e9999]

are these wings pulling the heater cap hard enough towards the block? If so and if there is a good exterior flange, how about a make your own gasket? Or heck, just some goop?

 

[IdahoDoug]

I don't think the wing arrangement provides a solid enough arrangement, actually. When you're tightening them in there's no clear "I'm seated and now you're applying seating pressure" feeling. There's also no feeling that you've tightened enough. The one I originally installed in 93 had badly deteriorated brass wings, which seemed also to have crushed/distorted. I replaced them with a scavenged unit.

So, there's not really a lot of seating pressure. The O rings seem to deteriorate and crack.

Here's what a trusted guy told me today. If I use a sealant and it lets go, I'm gonna puke up a lot of water fast. If I put another O ring in, then I will get the same warning I have now, which is a seeping block heater. He makes a good point. So, I'll be pulling the block heater out and running around town with it. Found a place with a good selection of Nitrile O rings. I'll be sure to buy a couple spares, and I'll be sure to post the mfr and p/n.

DougM

 

[concretejungle]

do you figure it's the silicates in the coolant that is doing the ring eating? Also, do you know if there is a protective gel or some lube you can put on the ring to minimize this? .........i imagine that's kind of what you are asking us.

 

[powderpig]

Permetex Aviation Gasket sealer #1 or #2 One is hard the other forms soft. Maybe the hard one will do the trick for you. I would have to look to see which is the hard formula(#1 or #2).
Good luck

 

[e9999]

btw, my block heater (which I never use) is doing fine apparently. Must have been there for 10 years.
It's one that has some male (IIRC) prongs recessed in the head. I don't remember it looking like brass. More like grayish. No idea if it's OEM.


added: it's on the DS of the block -not exhaust side- towards the front.

 

[80t0ylc]

I'm continuing to have trouble with the factory O ring's on the block heater breaking down after a few years, so am looking for a way to seal it into the block with out the ring. Anyone have a suggestion on what to use? .......The location is the exhaust side of the block and I don't know if that extra heat is causing the breakdown or what. ........DougM

Doug, if your looking for suggestions, I think your problem is the location + the o - ring choice for sealing it.

The o- rings are made of rubber, right? For longer life I think you have 2 choices:
1. Keep the location and change seal to something more heat durable.
2. Keep the o-rings and try a freeze plug with a cooler environment.
Just my .02. Good luck with whatever you choose.

 

[AJP]

The 97 instruction puts the block heater on the DS of the block ..

you could also re-install the frost plug and use an inline heater which are pretty generic and generally use just two hose clamps - easy to R&R
btw do you suppose that the heater coil is bottoming out on the internal jacket before the unit flange seats fully ?

 

[45Kevin]

You could try hi-temp silicone sealant around the flange. Available at home centers for fireplace flues. Gasket sealant may also work.

It is an odd situation because most block heaters last for eons. Are you sure you have the proper size?

 

[SUMOTOY]

I don't think the wing arrangement provides a solid enough arrangement, actually. When you're tightening them in there's no clear "I'm seated and now you're applying seating pressure" feeling. There's also no feeling that you've tightened enough. The one I originally installed in 93 had badly deteriorated brass wings, which seemed also to have crushed/distorted. I replaced them with a scavenged unit.

So, there's not really a lot of seating pressure. The O rings seem to deteriorate and crack.

Here's what a trusted guy told me today. If I use a sealant and it lets go, I'm gonna puke up a lot of water fast. If I put another O ring in, then I will get the same warning I have now, which is a seeping block heater. He makes a good point. So, I'll be pulling the block heater out and running around town with it. Found a place with a good selection of Nitrile O rings. I'll be sure to buy a couple spares, and I'll be sure to post the mfr and p/n.

DougM

Doug
Just a datapoint... I have done a few dozen water cooled turbo conversions to older Audi turbo cars. Part of that procedure is to remove a freeze plug in the engine and replace with one with a water fitting attached to it. I have routinely used Loctite red for this procedure, and have never had a leak.

HTH

Scott J
94 FZJ80 Supercharged

 

[MARLIN375]

I don't think it is temperature related. The O-ring is not exposed on either side and would be the same temperature as the block. Unless the heater itself is cooking it. (e9999 has lasted for 10 years, and he never uses it)
Do you plug it in and leave it? or do you have it on a timer?

I would be looking at the O-ring. Have you tried sourcing one from a heavy equipment service shop. Seems to me that a ring that can withstand hightemp and petroleum resitant like something out of an excavator valve pack or the like.

I know there is a difference between oil and water applications for O-rings. There is no way that your coolant should be eating the ring in only a couple of years.

 

[scottm]

Nitrile (aka Buna-N) O-rings are the most common in automotive, good to 212*F. You might try Viton, it's still fairly flexible but good to 395*F. I usually order from McMaster McMaster-Carr. You'll have to order a pack, might cost you as much as a buck. For sealants, I think you're looking at epoxy. Very permanent, but it'll work. There are lots of radiator repair kits at the parts stores, usually with a clay-consistency epoxy that hardens in place.

Lots of info about O-rings on the mcmaster site, click on "about O-ring materials" on the left side.

 

[IdahoDoug]

This block heater was mounted in the correct freeze plug per the instructions in 1993. However, there's a good point made that it's on the exhaust side and makes me wonder if the instructions were not changed from the '92 model's 4.0L engine which I believe did have the exhaust on the left side of the block. That means the supplier instructions may have been wrong, so I'm cooking O rings courtesy of their mistake. When I put the heater in the 97 years later, I simply put it in the same spot. Hmmmm....

I'm going to pull the heater, run around and try to find a new one, and failing that seal it in with RTV in a good quality. In a perfect world, I'll find a nitrile O ring that fits. FYI, when I've installed it before I've used O ring lubricant to be sure it slides/glides into place. When I pull them out, the appear to have been installed correctly and are uniformly distorted as normal. But they seem to have lost elasticity and thus seal pressure over time.

I guess I'd better have a freeze plug on hand as well in case of disaster - like the internal wings have broken down again or something similar so I'm not sitting with a disabled vehicle.

DougM

 

[IdahoDoug]

The bummer with ordering an O ring is the situation means I have to remove the O ring, guess at the size, order and wait for arrival with the truck disabled, then assemble. With the nitrile rings in town I'll get a few different sizes if nothing's obviously correct and see if it will go into the block. At least a chance I'll be up and running on the same day.

DougM

 

[scottm]

Is the O-ring pressed against a machined surface on the outside of the block? Sounds iffy if so. Maybe a pic would help. I could make you new "wings" out of stainless or some such. Perhaps a couple half-circle arcs with threaded holes would work better. Some O-ring applications aren't very critical for size, they can stretch if they're around something. If it's in an O-ring groove it'll need to stick out of the groove a bit. How do the machined surfaces look? If they allow even a tiny, imperceptible seep it will erode the O-ring.