operating temps?

[deano955]

Blacktiger,

 I searched and found a few threads though none described bubbling in the expansion tank. It seems a reasonable conclusion there is air in the system. The question is:



Anyone know the steps to bleed the cooling system? My dealer, Erico Motorsports in Denver, says the bubbles are normal. That don't do much for insuring confidence if owners say that bubbles are NOT normal. I would prefer to do the bleed myself but admit to not knowing the steps.



Thanks fellas,

Deano

[barjan]

Bubbling in the expansion tank is not normal. The level shouldn't even raise much. Liquid cooling is a closed system and should only contain coolant. coolant doesn't bubble unless it's overheating. So, bubbles come from things that shouldn't be. A faulty radiator cap, air in the system or worse, a broken head gasket (but it then usually starts to consume coolant).

[apache]

After doing some poking on my 97 I have seen some issues that might help you. If all the systems are of the open type( cap on rad and exp tank) then I see a problem ever getting it bled. On earlies there is no bleeded so one must use caution when servicing it. When the bike is on the side stand the cap is on the left which is the low side of the rad. Typically to evacuate all the air the cap must be in the highest position when it cools down and draws the previously expanded out coolant. This a a basic air will go to the highest point deal. I have set my bike against the garage wall on the throttle side leaned that way several times to help burp the system. Another possible air enterance area is faulty lines or clamps from the coolant tank to the radiator. a small amount of air entering here when things cool and coolant is drawn back in will start the air in the system all over. Look at old cars before coolant recovery systems were invented. You never saw a radiator full. After it was run hard and it expelled some coolant from expansion you always had air in there.

[NortonCharlie]

My 955 Tiger was blowing bubbles and sucking air.  There was some junk under the radiator cap.  I couldn't find a new one while it was apart so just cleaned up the old one and the problem went away.  It took a couple of warm ups to get the air out.  If your lucky a new cap may fix your trouble.

[apache]

Yes, thats one more thing I forgot to mention. If anything gets under the cap rubber seals it also will screw up its performance. Particulary the center part where there is a little round metal disc, its like a check valve of sorts.Kinda like the junk people put in car radiators (alumaseal).