coolant leak

OldFoggey · #1 (**permalink**) 10-19-2013, 08:36 AM

The last few months anytime I would pull my BackDraft out of the garage I would find a small area about 2 or 3 inches in diameter where coolant had dried. I've had my car a little over a year now and the leak is so small I've never had to add coolant to the tank. The other day while changing the oil I thought I'd investigate where it was leaking from. It appears that it's seeping coolant around the radiator drain plug because I can see an oily residue from the anti-freeze. I checked the plug for tightness and it's fine. Is there an O-ring or washer style gasket that might be going bad? Any other BackDraft owners had this issue?

Thanks and have a great weekend......Don

Mark Brye · #2 (**permalink**) 10-19-2013, 08:54 AM

Mine had an o-ring on the head of the screw and another o-ring about 3/4 of an inch down the screw.

OldFoggey · #3 (**permalink**) 10-20-2013, 09:54 AM

Thanks Mark. Working on a section of floor in my horse barn today so probably won't get a chance to look at it until next weekend but I think there's a minimum of 30% chance of rain all week so wouldn't chance driving it to work. Just seems odd that o-rings or even a gasket would get damaged of the screw hasn't been messed with.

Don

Mark Brye · #4 (**permalink**) 10-20-2013, 10:30 AM

My old E36 would start leaking every couple of years. Would just start dripping for a couple days then get worse. Be careful with a new plastic plug. They only go on at about 7 Inch/pounds or something like that. I think a new plug and o-ring was like 10 bucks from local BMW dealer.

OldFoggey · #5 (**permalink**) 10-24-2013, 05:31 AM

Thanks Mark. That's surprising that a BMW dealer would sell the radiator plug. Closest one is about 25 miles away but I'll try getting to them Saturday morning.

Don

OldFoggey · #6 (**permalink**) 10-24-2013, 05:37 AM

By the way. I bought a chrome coolant recovery bottle from Summit Racing and while I have the radiator drained I'll probably try replacing the catch can with the recovery bottle. I'll replace the radiator cap with one that has the relief portion that will allow the coolant to be sucked back in as the radiator cools but can't make heads or tails of the pressure rating on the old cap. Anybody have an idea of what the rating is on the BDR radiators. This is the standard radiator, not the optional heavy duty one.

Thanks...........Don

AKA EDDY · #7 (**permalink**) 10-24-2013, 06:37 PM

OldFoggy,I replaced my drain plug screw with an Ace hardware 10mm X 1.5mm Bolt. Installed an O ring with a flat rubber washer. Cost was around $5.00.

OldFoggey · #8 (**permalink**) 10-28-2013, 07:53 PM

AKA, you were right on about the 10m x 1.50. I bought a cap screw at Home Depot but they didn't have the rubber washer that I could find. I found that at Tractor Supply. The screw was treaded all the way to the head so I didn't use an o-ring figuring that the threads would cut it anyway. Seems to have cured the coolant drip.

Thanks...Don