How to Drain Radiator 84 300D - PeachParts Mercedes-Benz Forum

tobybul · #1 11-07-2006, 03:42 PM

Am trying to partly drain my radiator so I can check the stat but can find a drain cock underneath. Is there suppose to be one? Help would apreciated.

sailor15015 · #2 11-07-2006, 03:46 PM

Its on the driver's side, about a half-inch in diameter. Make sure to use a quarter or somthing like that, not a screwdriver, to remove and re-install it or you stand a good chance of messing it up.

tobybul · #3 11-07-2006, 04:05 PM

Quote:

Originally Posted by sailor15015

Its on the driver's side, about a half-inch in diameter. Make sure to use a quarter or somthing like that, not a screwdriver, to remove and re-install it or you stand a good chance of messing it up.

Thanks, but I do not see a drain cock.. is it suppose to be facing down at the bottom part or facing sideways? This may be a replacement radiator, not sure. I see 2 spots - one on right and one on left that look like where the rad is mounted at the base but I do not see a cock with a slat to turn. See pic below. stepping out for afew minutes to vote...

DeliveryValve · #4 11-07-2006, 04:33 PM

Quote:

Originally Posted by tobybul

Thanks, but I do not see a drain cock.. is it suppose to be facing down at the bottom part or facing sideways? This may be a replacement radiator, not sure. I see 2 spots - one on right and one on left that look like where the rad is mounted at the base but I do not see a cock with a slat to turn. See pic below. stepping out for afew minutes to vote...

It is supposed to be facing down. You second picture (the one with the a/c compressor shown) is where the drain is supposed to be. Check that area again, maybe you have a different type of plug.

Brian Carlton · #5 11-07-2006, 04:36 PM

The second photo shows the place where the drain plug "should" have been.

Instead, it looks like a plug that was placed into the bottom of the radiator instead of the drain plug. I'll bet that the round piece in the center of the hole is part of the radiator.

In this case you're forced to disconnect the lower radiator hose. Take the smaller of the two........the line to the expansion tank.

Also, be advised that this will only drain the radiator.........doesn't drain the head..........so, when you open up the thermostat housing..........all the coolant in the head will come pouring out.........get a suitable bucket ready.

tobybul · #6 11-07-2006, 04:50 PM

Quote:

Originally Posted by Brian Carlton

The second photo shows the place where the drain plug "should" have been.

Instead, it looks like a plug that was placed into the bottom of the radiator instead of the drain plug. I'll bet that the round piece in the center of the hole is part of the radiator.

Since I am not in a big yank for this, I am wondering if whoever had the car before and changed the rad might not just have screwed in the cock when it was new. I wonder if this rad will take a drain cock where that plug is...like the one below

Brian Carlton · #7 11-07-2006, 04:53 PM

Quote:

Originally Posted by tobybul

Since I am not in a big yank for this, I am wondering if whoever had the car before and changed the rad might not just have screwed in the cock when it was new. I wonder if this rad will take a drain cock where that plug is...

........If you pull the radiator, you'll know. It's not a big job to do this. And, you can then properly clean the passages between the fins with air/condenser cleaner/pressure washer. Just about all of them can benefit from this procedure.

Kynetx · #8 11-07-2006, 04:57 PM

I just ordered a replacement drain plug because the yahoo PO overtightened it and it snapped off when I tried to remove it.

tobybul · #9 11-07-2006, 05:18 PM

Quote:

Originally Posted by Brian Carlton

........If you pull the radiator, you'll know. It's not a big job to do this. And, you can then properly clean the passages between the fins with air/condenser cleaner/pressure washer. Just about all of them can benefit from this procedure.

Definitely a possibility.... I was really just trying to avoid making a mess and also reuse the antifreeze. It would have been a lot cleaner job if I drained it thru the cock. Am not opposed to pulling the rad but if this rad will not take a cock, am just gonna be disappopinted. Hate the thought of changing rad just b/c of this.

Brian Carlton · #10 11-07-2006, 05:22 PM

Quote:

Originally Posted by tobybul

Definitely a possibility.... I was really just trying to avoid making a mess and also reuse the antifreeze. It would have been a lot cleaner job if I drained it thru the cock. Am not opposed to pulling the rad but if this rad will not take a cock, am just gonna be disappopinted. Hate the thought of changing rad just b/c of this.

Well, if you drain the lower hose, you can reuse the antifreeze. But, as mentioned above, when you open the thermostat housing, you're going to get about three quarts that pour out all over the front of the engine and pick up all the loose oil on the way down. This usually can't be reused.

BTW..........I definitely think you're not getting enough sleep:

http://www.peachparts.com/shopforum/member.php?u=26722

tobybul · #11 11-07-2006, 05:40 PM

Quote:

Originally Posted by Brian Carlton

BTW..........I definitely think you're not getting enough sleep:

http://www.peachparts.com/shopforum/member.php?u=26722

r u referring to playing cards all night.... isn't toby cool... yep, thats toby... and he is the exact opposite when it comes to not getting enough sleep... he only wakes up to eat and use the bathroom.... otherwise, he will sleep thru a thundertorm...

Brian Carlton · #12 11-07-2006, 06:10 PM

Quote:

Originally Posted by tobybul

r u referring to playing cards all night.... isn't toby cool... yep, thats toby... and he is the exact opposite when it comes to not getting enough sleep... he only wakes up to eat and use the bathroom.... otherwise, he will sleep thru a thundertorm...

...........so, that's not you??

tobybul · #13 11-07-2006, 08:35 PM

Quote:

Originally Posted by Brian Carlton

...........so, that's not you??

LOL

I do need help on some other issues with this car that I posted in other threads which I believe some you responded to... such as a/c heating controls and the vacuum system.

I did find out today that disconnecting power to the monovalve on my 85 D makes the heater work better. This also tells me the mono is probably inoperative. I am chkg the stat on the 84 D cuz I think its either not there or is stuck open. The temp on the gage hovers at around 40F and the heat is luke warm. Between that and bad aux pump....not sure yet what 's causing the low heat. Haven't chkd the pump yet.

I know I fixed the central lock on the 84 D after sealing a bad vac element but system is not holding vac too well. It held with the Mightyvac b4 I connected the central lock to the car's vac system. Could be bad check valves? But I know the the vac system in the engine side is not holding vac. Not sure if its suppose to but will attack that some other time.

This'll keep me busy for a while.... good thing I enjoy this stuff... just keeps me from fly fishing...