Is there a preferred method... - PeachParts Mercedes-Benz Forum

rebreath · #1 08-24-2006, 10:18 PM

..to "burp" a 617 cooling system after changing thermostat?since changing the thermostat,I have been unable to get the air bubble out from the top of the radiator and upper hose.I have tried several things as follows
1-using pressure tester and disconnecting and plugging small overpressure line nipple on bottle and thumb over hose.pressurize,bleed and so forth-did not work
2-after thermostat was open,parked on very steep hill,heat on-more air in rad and still no change in bottle level.
3-drove highway speeds with coolant cap not tight-did not work either.
When I did the thermostat I did not drain whole system.only allowed enoughout to get to thermostat.when finished and refilling-I left lower hose connection to thermostat open until coolant had reached that level and then I reconnected it and continued filling with upper hose loose to allow air out and STILL I have air in there.PLEASE,PLEASE any help or suggestions...BTW yes,I also squeezed upper hose when both hot and cold-no help at all

300SDog · #2 08-24-2006, 10:29 PM

Yeah I've heard alot about squeezing the top radiator hose to clear air, but seems like a bunch of nonsense to me.

rebreath · #3 08-29-2006, 07:45 PM

Quote:

Originally Posted by rebreath

..to "burp" a 617 cooling system after changing thermostat?since changing the thermostat,I have been unable to get the air bubble out from the top of the radiator and upper hose.I have tried several things as follows
1-using pressure tester and disconnecting and plugging small overpressure line nipple on bottle and thumb over hose.pressurize,bleed and so forth-did not work
2-after thermostat was open,parked on very steep hill,heat on-more air in rad and still no change in bottle level.
3-drove highway speeds with coolant cap not tight-did not work either.
When I did the thermostat I did not drain whole system.only allowed enoughout to get to thermostat.when finished and refilling-I left lower hose connection to thermostat open until coolant had reached that level and then I reconnected it and continued filling with upper hose loose to allow air out and STILL I have air in there.PLEASE,PLEASE any help or suggestions...BTW yes,I also squeezed upper hose when both hot and cold-no help at all

need some assistance here please.thank you

bgkast · #4 08-29-2006, 08:02 PM

Try driving the car at high engine RPM for a minute or two (use a lower gear to get the RPMs up), then check the coolant level. This seems to burp the system quite well.

rebreath · #5 08-29-2006, 08:34 PM

Quote:

Originally Posted by bgkast

Try driving the car at high engine RPM for a minute or two (use a lower gear to get the RPMs up), then check the coolant level. This seems to burp the system quite well.

Tried that on the highway(70-80 mph)-like the energizer bunny-still there