Rubber expansion plugs - expected lifespan?

Darkwriter77

Resident Ranting Negative Nancy
5 Year Member
Jul 1, 2005
311
293
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Apache Junction, AZ
Just got done poking in two rubber expansion plugs. Don't gimmie hell for not using the brass or steel ones, please; I would have preferred to use those, but I don't have the liberty of being able to pull the whole motor out to install them, and there is NO way in hell I could knock those suckers into place with the motor in the car. Cleaned out the bores and reached into the block with my finger to scoop out all the rust and crap the stock steel plugs left (idiot P.O. ran straight water in there for a long time and rusted things badly), scraped away all the built-up scale around the backside of the holes, and I lightly sanded and then dried the bore surfaces. The rubber plugs poked in there snugly and after tightening 'em down, they feel quite secure - tried to pry them out with a screwdriver and pliers to test them, and they don't even budge. Started 'er up, burped the system let it warm up, and rev'ed it a bit - not a single drop of leakage. :nice:

Anyway ... what's the average lifespan of these buggers? I know they won't last forever of course, but I figure these neoprene boogers will last (in theory) as long as a heater hose. Just curious what everyone else's experience has been with them.

FWIW, I'm thinking of keeping a spare plugs in the car, just in case one of them decides to pop out when I'm out in the middle of nowhere. The driver's side plug actually doesn't look like it COULD pop out completely with the dipstick being in the way, but the passenger-side plug behind the starter looks to have enough room to shoot out, if it were so inclined. If I don't have any distilled water and/or antifreeze when one pops and leaves me stranded, I'll just pee into the radiator. :D
 
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35 views and 1 reply? Does nobody use these, or are they just a total unknown? :scratch:

I don't know how one could really over-tighten them unless they were using an air impact or something. You can only get about 2 or 3 full turns on them before the bolt starts turning with the nut, at which point they're already about as far squashed out as they can reasonably go, anyhow. Do they split or something once they're over-tightened? :shrug:

Again, no leaks so far, and I stomped on it a couple of times to make sure the pressure at WOT wouldn't pop 'em out - so far, so good. :nice:
 
Honestly depends how you drive the car. Put one on my motor (Back of head) and had issues with them popping out because i drive aggressively. So common practice was to keep a 1/2" wrench, Antifreeze, and a extra expansion plug at all times.

If you drive like youre taking a DMV road test you wont have issues. But if you spin it to 5 grand frequently.....well keep the 1/2", Antifreeze & Plug.
 
Okay, cool. I was just concerned because I thought I was kinda "cheating" by using these instead of the brass or steel plugs. But there was no way I was gonna be able to yank the whole motor to install these, nor did I have enough room to bang one home on either side with a hammer and socket with the motor in the car. I don't hot-rod the car at all - it's a CFI motor, there's not much there TO be hot-roddin' - and it's just my DD, so I rarely ever go WOT. I don't even think the motor even spins up to 5,000 RPM before the AOD shifts it to the next gear, anyway. :D

I'll probably keep a spare and some coolant with me, just in case, but at least now I feel a bit better about 'em. I was starting to think maybe they're just a band-aid to get you by for a week or two until you can put in a real plug, but if they last at least a year or two, then that's good enough for me. :nice:

Thanks, guys! :cheers:
 
Let's take her up to firebird this friday!!! haha, nothin is more fun than burning a gallon or so of antifreeze off the racetrack while everyone has to wait around for 30 minutes :rlaugh: Well if you get ambitious and need to borrow a cherry picker let me know, hopefully you don't need to though
 
I'd only take my '84 to the track if I wanted to absolutely humiliate myself. That thing probably only runs 16's, at best. :notnice:

Being that these plugs are the two bottom ones on the block, if one pops out, I'm gonna be losing almost every friggin' drop of coolant in the system in a matter of seconds. Might as well carry around TWO gallons of coolant or distilled water along with that spare plug. Again, the driver's side plug should at least be stopped from completely popping out due to the dipstick tube being right in front of it, so it might leak and spew a bit but I could at least pull it over and shut it down or maybe limp it home to change it out. But the passenger-side plug ... ugh. I doubt the starter would do anything to prevent that from shooting out at a really inopportune moment, so I'd inevitably wind up either changing it on the side of the road or getting a really expensive tow home. :(

The only time I ever expect to be pulling this motor is if I'm dropping in an '87+ roller long block. :D
 
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Just got done poking in two rubber expansion plugs. Don't gimmie hell for not using the brass or steel ones, please; I would have preferred to use those, but I don't have the liberty of being able to pull the whole motor out to install them, and there is NO way in hell I could knock those suckers into place with the motor in the car. Cleaned out the bores and reached into the block with my finger to scoop out all the rust and crap the stock steel plugs left (idiot P.O. ran straight water in there for a long time and rusted things badly), scraped away all the built-up scale around the backside of the holes, and I lightly sanded and then dried the bore surfaces. The rubber plugs poked in there snugly and after tightening 'em down, they feel quite secure - tried to pry them out with a screwdriver and pliers to test them, and they don't even budge. Started 'er up, burped the system let it warm up, and rev'ed it a bit - not a single drop of leakage. :nice:

Anyway ... what's the average lifespan of these buggers? I know they won't last forever of course, but I figure these neoprene boogers will last (in theory) as long as a heater hose. Just curious what everyone else's experience has been with them.

FWIW, I'm thinking of keeping a spare plugs in the car, just in case one of them decides to pop out when I'm out in the middle of nowhere. The driver's side plug actually doesn't look like it COULD pop out completely with the dipstick being in the way, but the passenger-side plug behind the starter looks to have enough room to shoot out, if it were so inclined. If I don't have any distilled water and/or antifreeze when one pops and leaves me stranded, I'll just pee into the radiator. :D
 
Here is my response. I am not sure when this part was started but it is now October 2015. I had a coolant leek I mean I do. I found out that two plugs that I can see by the firewall under some exhaust pipes are "puking"Brown sickness. I do not want to pull my motor to get to them. I heard that you might be able to half tap them in but usually you need to swing that hammer so I do not want to try gentley pushing them in. I researched and found out about the rubber plug, and maybe some other expansion medal one????????? I was told that the rubber one's do not last until I went and read HERE and googled you know™ I got a Ford Taurus that I might give these rubber one's a try. It seems to be my best option. I heard today that they cost ten dollars, still happy with that. My other though might try some plumbers glue on it as a back up plan. I am going to try and make enough room for the plugs by taking off some exhaust pieces that are in the way. I will probably put about twenty bucks in exhaust gaskets pre cut. I was thinking that it would not be bad if you can see well and move your hands to cover them up with an waterproof heat tempered medal bonding sealant with pressure resistance if you wanted to. The plug seems price effective and cleaner plus tried and true. I will try to update what I do. I appreciate your outputs already.
 
You need one of these...

FREEZE_PLUG_PULLER_GS_5332K_.jpg


It can be a DYI tool with a lag bolt and some heavy duty bar stock bent in a big vise...
 
a friend of mine used the rubber plugs in a few of his cars with nary an issue.
I've used them as well. I had a lower hose freeze once(forgot I was running straight water and water wetter), The pressure wound up pushing out one of the freeze plugs while I was driving. The plug was pretty rusted. So in a pinch, I used the rubber plug and actually forgot I had it in there until I swapped engines! That was years later! LoL
 
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Today I got most of one freeze plug out and got stuck on one that I can not get pliers on to rip it out piece by little piece. I tried to hammer one half in and spin it so I could grab the side of it but I could only get a hole. I should have thought about it better. I need a round file because in the one I got out left so scrap. I might be able to scrap it out with something. Also I feel like the rubber will cover small spots up.

I hope that nothing to big gets left in the block. I have all day to figure this out tomorrow.
 
Full day number three at it. Yesterday I found out a rubber block plug will not work because they are to long. Ford has a small plug and if you try something bigger it bottoms put to quick. I think Ford has these shallower plugs. So I do have a little room to ring a hammer. I tried installing metal ones but I had them backwards. I do not know what happened but yeah I had the pocket facing the block and tried hammering them that way. I realized it after I called it quits. I was also trying a Aviation Permatex cost eight dollars. It was a waste in my opinion I thought it was a hardening deal but it stays soft. I am going to ride my bike to the store to get a high temp sealer that is a glue or pressure resistant......!!!!!! I also got a smaller freeze plug in one of the holes I tried it because the 1 1/2" shallow steel plug was not driving. I think when I get it out the right plug should tap into place. They only go a 1/4" or so. I left my tools out and it rained last night. Well here is to staying positive, trying to PLAN out my action better and learning from effort. I would suggest try to get any thing you think you need from the store the first time. Grab different plugs and sealers and tools anything you end up not needing return it and buy a keychain.