Page 1 of 1

to bleed or not to bleed

Posted: Mon Oct 24, 2016 7:22 pm
by flyingzonker
( I posted this on the Burgmanusa forum recently. The bike in question has a built-in air bleed system which the PCX--at least not my 2013--doesn't but the bikes have the same basic infrastructure and the principle applies to both)

I removed the bottom panel and the lower leg shields, released the hose clamps on the hoses from the radiator and to (or from?) the water pump, let the old fluid drain, reclamped the hoses, poured new fluid in through the fill tube and then went to look for the air bleeder bolt. Oh boy! It was found in a place more inaccessible than I had imagined an air bleeder bolt could be. I took one tortured look at it and decided I would bypass the air bleed procedure as outlined in the book and just run the bike on the center stand a little, giggle it and hope for the best. I did this a few times, actually didn't see any bubbles appear in the mouth of the fill tube, but the fill tube mouth is pitched diagonally so that bubbles might have formed lower in the tube beyond my sight line--which is what I, at length, chose to believe had happened.


After this I filed the reservoir, stuck everything back together, and headed out. I had not gone one mile when I causally looked down at the temperature gage--wow, the dial was pegged on red! I immediately swerved into a gas station, parked, pulled off the panel under the handlebar and checked the reservoir--empty! I went in to the convenience store attached to the station, got a big cup of water (the water was dispensed from a line of taps--coffee, pop, water, etc) not stopping to consider whether the water was filtered or not, went out, poured the water into the fill tube until the tube would take no more, and tried to pour the rest of the water into the reservoir--no way was I going to get anything into the reservoir without a long necked funnel.


Here I was tempted to call it good enough and try to sneak, at a snail's pace, back home. But I thought better of this, girded my loins, and walked a mile down the road to Walmart, bought a gallon of ready mixed radiator fluid and a long neck funnel. I lug these back down the road to my bike, fill the reservoir and head back. The temp needle behaved the whole way home. Happy me.


The moral of this long story---don't skip the air bleeding procedure!

Re: to bleed or not to bleed

Posted: Mon Oct 24, 2016 8:12 pm
by relic
Went through the same story with a 350 Cummins diesel years back, learned my lesson, always bleed if you can
if not fill very slowly and carry some coolant with you-watch the temp gauge and be ready to add coolant
I think what happens is air gets trapped by the thermostat and when operating temp is reached-you're all of sudden
in one of those oh no moments
Pretty hard to get an engine up to operating temp on a stand or at high idle
don't skip the air bleeding procedure!