Dan Aseere
Viper Owner
I have 94rt10 and 97gts and want to drain coolant. Am I looking for trouble if I remove engine drain plugs. 94 has 8000 miles and 97 has 4000 miles. Please reply.
engine drain plugs
- Thread starter Dan Aseere
- Start date
Define trouble...it helps to have a pipe plug socket set(English and metric) for the block plugs (which ARE important to drain in most eyes)...but remember that these plugs are pipe threads with no torgue specs given in service manuals.
There is a good write up on Gen II in this section by " Ron" about 6-8 months ago.
There is a good write up on Gen II in this section by " Ron" about 6-8 months ago.
GTS-ACR
Enthusiast
Do it. Its a piece of cake and you'll get all of the coolant out. I made a square ended toll with a grinder to remove the steel plugs and replaced them with brass hex heads and pipe dope.
ACR Joe
Enthusiast
I have tons of hands on experience and mine were so tight, I decided it was far too risky to try more aggressive removal methods. So I'll change the coolant once a year; no big deal. If the engine were sitting on a stand upside down, removal would be far more achievable.
As far as a brass plug in an aluminum block is concerned, I'm no metallurgist but this could be a receipt for a sacrificial anode. Comments?
GTS-ACR
Enthusiast
I was told that the steel plugs are more harmful to the aluminum block and to actually replace them with brass plugs. Please chime in if this is a bad idea.
Chuck 98 RT/10
Enthusiast
I've had enough bad luck with drain plugs that I don't want to risk it on the Viper. I just cycle the fluid.
jk
Enthusiast
I was tentative about the plugs also, but decided to give it a try. They backed out easy enough for me, but if they were stubborn I was going to leave them alone. I also had to make a special tool by grinding down a ratchet extension. There is another plug by the thermostat (used when you refill coolant) that was real stubborn, so I did not risk removing that one. That post mentioned previously was of great help to me, worth checking out.
I must admit that I chickened out on tampering with the Gen II thermostat plug....REAL close to the intake manifold...did have a machine shop make me a 3/16" square tool as pipe plug socket would not fit...but still backed out after I needed 40 lb-ft. of torque to remove a "test plug" on a spare thermostat housing that i bought....and, I've had NO PROBLEMS with air in thermostat to date, noting that I do install Roe Racing silicone radiator hoses with the built in bleeder (admittedly "downstream" from the thermostat)on ALL of our Vipers at the time of first coolant change.
FRANK
Enthusiast
Upon changing out my head gaskets on my 94 I tried getting those plugs out. I had the car on my lift and even with a small breaker bar, I wound up snapping a Snap On pipe plug socket in the process. As soon as that happened, I decided the little bit of coolant left in there is no big deal. A little risky. The last thing you need is cracking that area or stripping the block. No way. Just ain't worth the potential problem...
If you're gutsy...try heating the area with an acytlene torch and then give it a try...heat usually unsticks even the tightest bolts/nuts/fasterners...
My decision is to forget getting them out!
If you're gutsy...try heating the area with an acytlene torch and then give it a try...heat usually unsticks even the tightest bolts/nuts/fasterners...
My decision is to forget getting them out!
GTS Dean
Enthusiast
Most pipe plugs are a problem if they are left in place for a long time. I've found a couple of things that help ease the pain.
1) If there is room, use a drift punch and hammer to hit the center of the plug with several sharp licks.
2) When you have the removal tool on the plug, give it just a little turn *tighter* before you try to unscrew it.
3) If those things don't work, an O-A brazing tip or a miro torch can be used to gently heat the area around the female threads, but you don't want the aluminum to get over about 300F. Then try methods 1 & 2 again. 9 times out of 10, you will get the plug out without ruining anything.
You should also be very careful about the radiator tank drain plug. The boss is soldered into some fairly thin metal and could distort or tear out with too much torque on a stuck plug.
1) If there is room, use a drift punch and hammer to hit the center of the plug with several sharp licks.
2) When you have the removal tool on the plug, give it just a little turn *tighter* before you try to unscrew it.
3) If those things don't work, an O-A brazing tip or a miro torch can be used to gently heat the area around the female threads, but you don't want the aluminum to get over about 300F. Then try methods 1 & 2 again. 9 times out of 10, you will get the plug out without ruining anything.
You should also be very careful about the radiator tank drain plug. The boss is soldered into some fairly thin metal and could distort or tear out with too much torque on a stuck plug.
Ron
Enthusiast
I've taken the block plugs out of 2 different 1996 Vipers and while they all "snap" a bit when they loosen, I did not fear damage. Quite a bit of coolant was trapped up there. Big deal if you don't remove? Probably not.
On the other hand as Steve mentions, the thermostat air bleed is way too tight (and the head is too small to get enough torque on it anyway) to risk removal unless the housing is off for a thermostat change. I've only heard of one person that has successfully removed it while on the car. Careful refill, burping and starting practice eliminates the need anyway. The upper hose bleeder helps with the burping but does not free the air trapped under the thermosat. That is only removed via the thermostat bleeder or when the thermostat opens. The problem is that the air trapped under the pellet delays the opening until you're in an near overheat situation. Shutting the engine down after warm up and then letting the heat soak open it solves the issue.
The culprit is not the age (first 1996 was 4 years old, second was 6 when plugs were first removed) or the plug itself, but a brown thick locktite type sealer that is way over applied. I reinstalled the block plugs with antiseize and then added a dab of silicone seal on the head of the plug smeared over to the block. Just enough to prevent vibration from backing it out. 10K miles later, perfect.
As Dean states, the radiator plug is probably the most dangerous to remove the first time. Very flimsy area of the tank.....
On the other hand as Steve mentions, the thermostat air bleed is way too tight (and the head is too small to get enough torque on it anyway) to risk removal unless the housing is off for a thermostat change. I've only heard of one person that has successfully removed it while on the car. Careful refill, burping and starting practice eliminates the need anyway. The upper hose bleeder helps with the burping but does not free the air trapped under the thermosat. That is only removed via the thermostat bleeder or when the thermostat opens. The problem is that the air trapped under the pellet delays the opening until you're in an near overheat situation. Shutting the engine down after warm up and then letting the heat soak open it solves the issue.
The culprit is not the age (first 1996 was 4 years old, second was 6 when plugs were first removed) or the plug itself, but a brown thick locktite type sealer that is way over applied. I reinstalled the block plugs with antiseize and then added a dab of silicone seal on the head of the plug smeared over to the block. Just enough to prevent vibration from backing it out. 10K miles later, perfect.
As Dean states, the radiator plug is probably the most dangerous to remove the first time. Very flimsy area of the tank.....
