block heater sealant? (1 Viewer)

[IdahoDoug]

Well, the advantages of a dry climate accrued to me today. I had to retighten the block heater as it's still seeping. In order to get a full size screwdriver on it I had to remove the rear manifold heat shield. With limited space, I had to use the small 1/4" drive and had little leverage. Amazingly, they popped loose easily after 10 years!

Anyhow, if this final tightening still allows seepage I'll have to remove it and consider a new gasket and/or sealing options. Anyone have a suggestion on what to use to seal a rubber gasketed brass block heater into a cast iron block? Something that can be removed at some point, I hope.

DougM

 

[cruiserdan]

Doug,

I don't have an answer for you but I have a suggestion who to ask. Block heaters are ubiquitous in the Diesel community. How about asking a nearby HD truck repair place what they use?


D-

 

[Landpimp]

Doug. Stupid question but where is your block heater mounted? I thought they replaced a feeze plug?

 

[cruiserdan]

John,

That is correct. The heater occupies a freezeplug hole. It has an odd-looking o-ring around the edge and a molly bolt-looking-thing on the back to secure it in the block.

Doug's is seeping around the edge.

 

[Landpimp]

[quote author=cruiserdan link=board=2;threadid=8586;start=msg73620#msg73620 date=1071027339]
John,

That is correct. The heater occupies a freezeplug hole. It has an odd-looking o-ring around the edge and a molly bolt-looking-thing on the back to secure it in the block.

Doug's is seeping around the edge.
[/quote]

Hmm I thought they were just pounded into the hole.......at least my 78 fj55 one looks like it is.

 

[IdahoDoug]

Pimp, if you look closely you'll see a screw head under the plug.

Well, looks like it's still seeping. I'm thinking it might be best to remove it, clean out any crud accumulated from seepage in the freeze plug hole, and replace the O ring before reinstalling. Anyone know if the O ring needs to have any special properties (oil resistant, temp resistant, synthetic, etc)?

Thanks!

 

[IdahoDoug]

The seepage seems to occur upon startup in the morning and I was feeling uneasy that there may be another leak. So I waited for the truck to cool, then went out this evening and started it. Got under the truck and immediately saw a thin trail running out of the block heater. So, good that this is the leak, but things just got a little more urgent on my request for O ring conditions. Anyone have an opinion? Are their "upgrade" O rings out there that can handle anything? Obviously spending $3 on one vs 78 cents is not an issue if I don't have to ever remove the block heater again, so that's what I'd like to do.

DougM

 

[Rich]

http://www.oringsusa.com/html/elastomers.html

Use some silcone grease to lube the oring. The purpose of the lube is not to block a leak but is to enable the oring to move as necessary to form a good seal between the block & plug.

 

[IdahoDoug]

Great site! Looks like EDPM is the material I'm looking for. They have a neat little diagram that helps you decide based upon the operating environment and conditions. Now I've gotta bite the bullet and pull it out - essentially disabling the vehicle until I find the proper size/material O ring.

Thanks, Rich!

DougM

 

[Scamper]

Doug,

I've been using this stuff for years:

http://www.duniway.com/images/pdf/DC-150-datasheet.pdf

It's virtually indestructable and works great on sealing o-rings; it's so thick that it helps to keep things in place during assembly too. One tube lasts a heck of a long time (I've had one now for about 10 years). It will beat out any grease you'll find for longevity and resistance to heat and chemicals.

Tom

 

[IdahoDoug]

Well, major crisis averted by being a little aware of my vehicle. Pulled the block heater out of the block and found the O ring had rotted a bit. Atop that, it uses a toggle like thing that flares out inside the block as you tighten it, and the reason it began leaking more after I tightened it is the brass toggle thing had cracked and failed. Must have overtightened it, but still I'd have expected brass to bend rather than kinda crumble. Fortunately all chunks accounted for.

Called CDan for O ring advice. Found an O ring that fit, then further cannibalized the Supra block heater I've had laying around forever to replace the toggle thing. Stuffed the thing back in, replaced the 1.3 gallons or so of coolant that ended up on the garage floor and it's good to go.

Also got tired of listening to the scratchy sound of the horn rim contact when I turn the steering wheel now that it's cold. Fired a spot of white lithium grease onto it via the blinker stalk hole and now that's quiet again. Only does that when it's really cold, now it won't for another 5 years...

DougM

 

[Beowulf]

Tom,
And where would a Smart Shopper find some of that Dow Corning grease?
-B-

 

[Scamper]

[quote author=Beowulf link=board=2;threadid=8586;start=msg74359#msg74359 date=1071120911]
Tom,
And where would a Smart Shopper find some of that Dow Corning grease?
-B-
[/quote]

B: don't know about the Smart Shopper part, as this stuff is a bit spendy, but one tube will last forever since you don't need much to do the job. Here's a place you can get it on the internet.
http://www.2spi.com/catalog/vac/dow.shtml
I got mine many years ago at a local lab supply shop. It is/was designed for use in a chem lab for sealing glassware surfaces under vacuum and that sort of thing. One warning: if you get it on something you don't want it to be on, it's VERY hard to get all of it off--the stuff is tenacious. In the lab, the way we would remove it was by soaking the glassware in a concentrated dichromate-sulfuric acid solution (very nasty).

Tom

 

[Beowulf]

Thanks Tom.
-B-