Anyone know block drain and thermostat bleeder plug socket sizes?

[Ron]

Would like someone to verify GENII engine block and thermostat bleeder plug socket sizes and torque settings. These are the female square socket plugs underneath the engine and in the thermostat housing.

Thanks

 

[Steve-Indy]

Gen II thermostat bleeder plug is 3/16"...per Charlie.

 

[Steve-Indy]

Gen II thermostat pipe plug air-vent IS indeed 3/16"(square)....I bought a NEW housing in order to have a model with which to play while I tried to permanently to solve problem of "hard time" bleeding this little devil...RIGHT out of the box, the plug is a BEAR...it has a resin of some type on THE DOWN SIDE (internal)and of the plug that I scraped away, AND then used penetrating on the plug, THEN, I used a Snap-On 3/16" male pipe plug socket and PROMPTLY rounded out the square hole (I planned to discard this plug anyway). NO WONDER, several techs have told me that they NEVER fuush air this way !!!! More later !!!

 

[FRANK]

That's why I gave up on draining the two antifreeze drain plugs on each side of the block near the bellhousing area. I snapped on customized extension and used another one with every ounce of strength and it wouldn't budge! I figured the hell with it because with my luck the aluminum block would crack before the plug would budge. That would mean pulling the motor and heliarcing the cracked block...

Forget penetraing oil or WD40 etc because it will just drip off...

 

[Ron]

Thanks Steve - WOW! I had no idea the thermostat air bleed was such a bear. I do remember having a tough time with the block plugs as Frank mentions, but they eventually loosened cleanly and I reinstalled with antiseize.

Perhaps a bit of properly applied heat would help?

 

[FRANK]

I had my acetelyne torch right there but decided not to use it. If it were a cast iron block I would have heated it up. I figured when the heads were loosened up the antifreeze would run out anyway.

 

[Steve-Indy]

Well, Ron and Frank...I FINALLY got my plug removed from the thermostat cover...drilled it, then used a Sears #4 extractor (labled for use on a 1/8" pipe plug)...noting that it took over 40 ft-lbs of torque (needle deflection type---crude, but still a reasonable estimate)...which , in MY opinion is WAY TOO MUCH torque for this type of plug given it's soft metal, small size, and location...possibly related to the type/amount of "sealer" used on the threads.

There is NO DOUBT in my mind that trying to bleed air through the stock setup...ON THE CAR has risk of damage to the car...several techs have allowed that they skip this step for that very reason.

Perhaps this is why one sees a small brass "brake-bleeder-type-plug" sttting on top of the Gen III thertmostat housing....guess "who" plans retrofit...even the $1.99 brass 1/8" "universal" radiator pitcock from Autozome would SEEM better to ME. (THANKS for the tip, Charlie).

Admittedly, I have changed coolant on Gen II's without venting air thru this port...just thought it would be good to try to "go by the book"...have now changed my mind on that one !!

P.S. I have installed Roe Racing's silastic radiator hoses with the built in Schrader valve pre-installed on the upper hose one of our other Gen II's....SLICK MOD, Sean !!!

Hopefully, some of the REAL PRO'S who frequent this board can tell me what it is that I am missing on this issue.

 

[FRANK]

That's why I didn't bother forcing them out. I just got bad vibes with those plugs. I gave the one everything I had while on the lift. It didn't budge. Eventually something would have let go and after breaking on extension, I left well enough alone.

I am so glad I left them alone. Those plugs in the block seemed welded in!

 

[Ron]

Thanks Steve for the great detective work. Looking forward to your solution.

Being the stubborn person I am, I will eventually try to remove mine and then anti-seize it for future use. Thanks to your experimentation, I will take extra precautions now that I know the risk.

Has anyone succesfully removed the thermostat bleeder on a GENII without damage???

 

[kverges]

Shameless plug for bleeding coolant, hot or cold:

http://www.viperclub.org/news/bleedersannouncement.html

 

[Steve-Indy]

Thanks, Ron.

Keith, GLAD you reminded the group about your system...it should work well.

I became interested in the RECOMMENDED procedure for de-airing the thermostat on Gen II's because it was noted in the later service manuals (was NOT in the 96 GTS Service Manual, NOT in the 97 Service Manual, FIRST noted in the 98 Service Manual).

At this point, I have purchased a few 1/8" pipe plug sized bleeder valves that FIT PERFECTLY into the pipe threads of the stock thermostat housing, which will make future air purging of the thermostat much easier as these bleeder ******* have a small hex nut, and work just like a brake bleeder ******...and, with a small hose attached, one can avoid spilling coolant on the serpentine belt.

Note: this is the same type of bleeder that is CURRENTLY IN PLACE on the the top of the Gen III thermostat housings...MUCH EASIER from the get-go !!!

P.S. If one is already changing one's Gen II thermostat (and therefore has already removed the intake manifold) the installation of such a bleeder ****** would be much easier...and SAFER.