coolant system drain

D

dirty old man

Registered
Have my '94 up on 4 ramps to replace front bumper cover and do a good bit of neglected PM, including a drain of coolant and refill with new. The owner's manual says 16 qt. capacity.
Opened the drain on pass side radiator and only got out 4 qts., leaving 12 qts in rest of system.
Need to get out more coolant than this. Block drain plugs are barely visible, doubt I can access well enough to remove.
Any body got any ideas on how to get more coolant out?
I had planned to change all the hoses also, but they look good, no swelling, no cracking, no mushy feel. Males me strongly consider leaving them on and just keeping a watch on them. I've had the car since '95, so I'm sure the hoses are original, amazing!
Dave
 
Dave,

Remove the lower radiator hose at the radiator, that'll get a bunch of coolant out. You're not going to get the full amount of coolant out, but 4 qts definitally isn't enough. Also....make sure you remove the radiator cap, or the system will create a vacuum and nothing will come out.

On the hoses.....I wouldn't worry about them unless they're showing signs of concern, such as swelling, cracking, leaking, or corrosion inside.
 
There is no radiator cap to remove lol. Jesse is probably talking about the overflow tank cap.

I usually get about 6-7 quarts out of the system when bleeding through the radiator. The only other way would be to hook it up to mashine and "flush it". Some dealers only charge $99 for that. It may be worth it since they use about $30 worth of coolant and you don't have to deal with cleaning up the mess.

Otherwise it is the drain plugs from the block.

Also make sure that you fill it up through the cross over tube otherwise you will trap air in the system causing your car to overheat.
 
Stopped by the shop for awhile this afternoon and pulled the lower radiator hose and got about another qt. of coolant out, maybe a little over that, as I spilled a little and couldn't measure that which spilled. Hose is still off and a drop falls every six(6) seconds. This is about an hour later, still dripping. Don't think that it would drip that long unless some coolant is slowly bypassing whatever is blocking it from draining, thermostat maybe?
Yeah, the reservoir cap and crossover cap are both off, and I do know to refill thru crossover. I decided to leave it dripping till tomorrow just to see what happens there, dripping much too long to just be drainage from what little more I drained today.
Unless it decides to open itself up and drain some more tonight, I guess tomorrow will find me trying to get the block drains out!
Dave
 
I just remove the t-stat lower housing. If your lucky, the t-stat will stick up. Then a quick yank and it all comes out. Well, not ALL.... But more than the bulk of it.
 
Unity,
You just confirmed my suspicions that the thermostat was holding back a good bit of coolant. Tomorrow I'll pull the bottom off the housing and we'll see what happens!
I'm quite impressed withj the coolant I had in it. Had the Prestone Extended Life (same as GM Dexcool) in it. Ashamed to say that when I checked the records I keep that this coolant had been in the MK8 for over 10 years!
It was still bright orange and just as clean and clear as when I poured it in!
Dave
 
Ummm... I thought Dave would've known this. On these cooing systems, the t-stat should be open to drain the system. See #1 below...

Cooling System Draining, Filling and Bleeding

NOTE:
Some coolant/water will be retained in the cylinder block if cylinder block drain plugs are not removed. When refilling cooling system after flushing, adjust coolant mix ratio to obtain a 50/50 mix. Be certain to account for approximately 5.1 quarts of water left in the cylinder block when drain plugs are not removed.

1. Bring engine to normal operating temperature and turn engine OFF.

WARNING:
NEVER REMOVE PRESSURE RELIEF CAP UNDER ANY CONDITIONS WHILE ENGINE IS OPERATING. FAILURE TO FOLLOW THESE INSTRUCTIONS COULD RESULT IN PERSONAL INJURY AND/OR DAMAGE TO THE COOLING SYSTEM OR ENGINE.

WARNING:
TO AVOID BURNS FROM SCALDING COOLANT OR STEAM, USE EXTREME CARE WHEN REMOVING THE PRESSURE RELIEF CAP.

2. Remove engine appearance cover.

3. Drain cooling system as follows:

a. If cooling system is still hot, carefully wrap a thick cloth around the pressure relief cap and rotate slowly until pressure begins to release. Step back until the pressure is released.

b. Then rotate pressure relief cap until free. Remove the pressure relief cap.

c. Open radiator drain cock and disconnect engine coolant return hose at coolant inlet connection on oil filter adapter to drain the coolant system.
Click to expand...

Also, there should be a 'bleed hole' in the t-stat that not only helps in 'burping' the system when filling, but also helps when draining the system.
 
Thx JP, I guess it was because the coolant system is laid out so different than most other cars that I never even thought about pulling the thermostat to drain!
Most cars place the thermostat in the outlet from engine to radiator and on ours it's on the inlet to engine, which on most cars is integral with the water pump and pumped directly into engine from pump, as you know. So 50 plus years of twisting wrenches had me doing a drain the same old way! I gotta find a paper manual or either dig up that CD manual I bought from Leo years ago!
Must not be a bleed hole in the thermostat now in engine (it's the original), but I think I'm gonna replace it while the housing is apart, and if there isn't a bleed hole, I'm gonna drill one! Maybe 1/8"?
Dave
 
You can also flush the system by sticking a running garden hose into the overflow tank and running the engine. All the water will flow out the disconnected lower radiator hose and your system will be cleaned out in a matter of minutes. You'll still have water in the system, but it will be clean water. You then hook the radiator hose back up and start filling with pure coolant. Once you've filled it with 8 quarts, you fill the rest up with water...perfect 50-50 mix, and it's all clean.
 
logres said:
You can also flush the system by sticking a running garden hose into the overflow tank and running the engine. All the water will flow out the disconnected lower radiator hose and your system will be cleaned out in a matter of minutes. You'll still have water in the system, but it will be clean water. You then hook the radiator hose back up and start filling with pure coolant. Once you've filled it with 8 quarts, you fill the rest up with water...perfect 50-50 mix, and it's all clean.
Click to expand...

Great Tip! :)
 
dirty old man said:
Must not be a bleed hole in the thermostat now in engine (it's the original), but I think I'm gonna replace it while the housing is apart, and if there isn't a bleed hole, I'm gonna drill one! Maybe 1/8"?
Dave
Click to expand...

Replace it - after 10 years it has served well.

A 1/8" hole would be the biggest I would do. I think the typical bleed hole is maybe 1/16" or maybe 3/32" - they are pretty small.
 
logres said:
You can also flush the system by sticking a running garden hose into the overflow tank and running the engine. All the water will flow out the disconnected lower radiator hose and your system will be cleaned out in a matter of minutes. You'll still have water in the system, but it will be clean water. You then hook the radiator hose back up and start filling with pure coolant. Once you've filled it with 8 quarts, you fill the rest up with water...perfect 50-50 mix, and it's all clean.
Click to expand...

I was always wondering about this flushing method. It is indicated on the back of Prestone coolant, but I always wondered how much will remain inside the engine.

Please keep in mind that regular water has a lot of deposits that are harmful to your engine, you want to use distilled water since it has a much lower miniral content but either way getting all the coolant out is better than the regular drain and refil. The best option would be to use a water filter similar to what LEO is selling.
 
maxmk8 said:
Please keep in mind that regular water has a lot of deposits that are harmful to your engine, you want to use distilled water since it has a much lower miniral content...
Click to expand...

The wife caught me buying distilled water by the gallon jugs and gave me grief when I told her it was for the car.

Of course she reminded me I had told her we didn't need bottled water for the house when she wanted a water cooler for the kitchen! :eek:
 
dirty old man said:
Must not be a bleed hole in the thermostat now in engine (it's the original), but I think I'm gonna replace it while the housing is apart, and if there isn't a bleed hole, I'm gonna drill one! Maybe 1/8"?
Dave
Click to expand...

I just replaced my T-Stat, I did have a bleed hole with an "I" shaped piece in it. Could this be the reson for your slow drip?
 
Be2lose said:
I just replaced my T-Stat, I did have a bleed hole with an "I" shaped piece in it. Could this be the reson for your slow drip?
Click to expand...


Yes....that little brass piece is their for allowing air to bleed by but preventing coolant to pass freely after you've reached Op. Temp. I'm sure this hindered the flow of coolant when you were watching it drip.
 
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