87TDT drinks coolant - Page 2 - PeachParts Mercedes-Benz Forum

punkinfair · #16 01-06-2009, 10:36 PM

this is an old post but i thought it would be good to update. one day a few months ago (still wondering why the car was running perfectly yet sipping coolant) i removed the coolant tank. it turns out the coolant was leaking from a crack on the back of the tank. the coolant was leaking slowly enough that it never hit the ground or made much of a mess. it didn't leak until the car was hot and then the hot coolant mostly evaporated before it hit the ground.

once i found out what was happening i removed the wires for the sensor and just left to coolant level low in the tank below the crack and it stayed there. i finally got around to replacing the bottle and all is well.

husk · #17 01-07-2009, 12:38 AM

Thanks for the update you must be relieved!

retmil46 · #18 01-07-2009, 12:40 AM

Found a similar problem on Rudolph. At first I thought it was due to someone having put on the wrong pressure radiator cap - 13 psi instead of 20 psi. But upon startup with the proper pressure cap installed, once warmed up I noticed air/coolant bubbling up from the seam where the metal radiator cap fitting joined the plastic tank. Some JB Weld putty took care of it for the time being until I get around to putting in a new tank.

Another culorit I found a while back on the now-wrecked '87 was the ancient rotted braided hose going from the surge tank down to the recovery tank in the fender well. PITA to replace - had to pull the battery and the fender well liner.

a2t · #19 01-08-2009, 11:51 PM

I always tee in a pressure bottle to the lines and pump to 15 or so psi. see if it holds. All these stupid leaks are easy to find with engine at ambient, in the quiet garage with engine off. I dont know how many leaks Ive found this way. Glad it wasnt more serious, and I'll check my coolant bottle, that thing is a relic.

a2t · #20 01-08-2009, 11:52 PM

oh yeah, somebody owes somebody a pizza.

Bio300TDTdriver · #21 01-09-2009, 01:00 AM

Quote:

Originally Posted by a2t

oh yeah, somebody owes somebody a pizza.

Yes, Hattie owes Brian a pizza. Good thing he didn't pull the head.

Brian Carlton · #22 01-09-2009, 09:19 AM

Excellent outcome. Glad the head didn't need to come off.

Oh Chris........where's my pizza........???

Bio300TDTdriver · #23 01-09-2009, 10:16 AM

Quote:

Originally Posted by a2t

I always tee in a pressure bottle to the lines and pump to 15 or so psi. see if it holds. All these stupid leaks are easy to find with engine at ambient, in the quiet garage with engine off. I dont know how many leaks Ive found this way. Glad it wasnt more serious, and I'll check my coolant bottle, that thing is a relic.

It's a good idea to replace that tank, even if it isn't cracked. The new ones come with a silicone pack that helps to protect the cooling system.