GL1800Riders Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
849 Posts
Discussion Starter #1
Hey Guys,

Could use some advice here... Getting ready to do coolant flush/change and checked the radiator cap with MityVac pressure setup... Pressure didn't release until 20+ PSI and additionally, results were inconsistent - saw some readings lower and some higher... So with the spec on the cap being 16-20PSI, is there anything to worry about here... Additionally, the cap didn't hold pressure very well - it leaked down fairly quickly...

If the pressure release is on the high side, what is the effect on the cooling system as I think that would raise the boiling point... I haven't really had any problems to speak of with my 09 Level III Wing, but I did see the coolant temp gauge go into the red area last year while climbing a long grade, pulling my trailer, in the summer heat... Once we got moving again at highway speeds, the temps went down to normal... It seems like my fans cycle a lot, but I have no basis for comparison... The 1800 is a bit of a different animal compared to my 1500 that I rode for 20+ years...

DSCN0156.jpg DSCN0154.jpg

Should I replace the radiator cap or do you think it's OK??? I guess I could just replace it - it isn't that much money... I have the UView 55000 that I will use for the coolant change so there should be no concern regarding air pockets... I just wnat to get the cooling system in tip top condition now that I am living in Tennessee where the summers are considerably warmer than where I used to live...

Les
 

·
Vendor
Joined
·
17,372 Posts
Try rinsing the cap under running water and rinse under the rubber seal. Also, push in and out on the cap a few while under water. Then test it. A good cap will consitantly release pressure down to 16-20 lbs and hold it.
 

·
Registered
Joined
·
849 Posts
Discussion Starter #5
Thanks for all the info guys - I appreciate it... The cap is releasing in the high end of the 20lb range so according to Honda specs, it is still good... The Mity vac gauge does show it leaking down and this is what I am unsure of... This is a brand new out of the box Mity Vac Pressure Checking device, so I expect it to be good, but one never knows, and one never says never :roll:... I did check the connections with a bubble solution for leaks and didn't see any leaks so I am in doubt that the cap is OK with it leaking down after it pops off at 20+ psi... Like I said, I guess I could replace the cap, but it's not my style to replace parts that do not need to be replaced...

The bike usually ran what I consider to be "normal" except my fans seem to come on sooner than my buddies... The bike has never puked out anti-freeze and as I mentioned before, I only saw the gauge go to the red line one time while pulling a grade out west in a traffic back-up (classic GW overheat) and again under similar circumstances climbing a mild grade in desert heat under 20MPH...

I bought the bike used early in 2013 with 9600 miles on it... There were no service records available from the previous owner so I assume the coolant has never been changed or have other fluids, which I will be doing shortly along with coolant... I have changed the oil a time or two so far...

I do have the Honda shop manual and have your DVD's Fred so I'm in pretty good shape as far as information is concerned... Just a little puzzled with this radiator cap thing... I'll will be using Honda pre-mix coolant and 4 oz of water wetter just for a bit of insurance...

Thanks again guys ;)

Les
 

·
Registered
Joined
·
1,419 Posts
Every once in a while I run a Q-Tip under the rubber thingy
 

·
Registered
Joined
·
3,334 Posts
Thanks for all the info guys - I appreciate it... The cap is releasing in the high end of the 20lb range so according to Honda specs, it is still good... The Mity vac gauge does show it leaking down and this is what I am unsure of... This is a brand new out of the box Mity Vac Pressure Checking device, so I expect it to be good, but one never knows, and one never says never :roll:... I did check the connections with a bubble solution for leaks and didn't see any leaks so I am in doubt that the cap is OK with it leaking down after it pops off at 20+ psi... Like I said, I guess I could replace the cap, but it's not my style to replace parts that do not need to be replaced...

The bike usually ran what I consider to be "normal" except my fans seem to come on sooner than my buddies... The bike has never puked out anti-freeze and as I mentioned before, I only saw the gauge go to the red line one time while pulling a grade out west in a traffic back-up (classic GW overheat) and again under similar circumstances climbing a mild grade in desert heat under 20MPH...

I bought the bike used early in 2013 with 9600 miles on it... There were no service records available from the previous owner so I assume the coolant has never been changed or have other fluids, which I will be doing shortly along with coolant... I have changed the oil a time or two so far...

I do have the Honda shop manual and have your DVD's Fred so I'm in pretty good shape as far as information is concerned... Just a little puzzled with this radiator cap thing... I'll will be using Honda pre-mix coolant and 4 oz of water wetter just for a bit of insurance...

Thanks again guys ;)

Les
Radiator Caps on modern systems work both ways: ie they have a release pressure that allows the cap to open from the Cooling System to the Atmosphere when the pressure in the Cooling System exceeds atmospheric pressure by some amount (usually 15 - 16 PSI) and they also open the other way (so to speak) when Atmospheric Pressure exceeds the pressure in the Cooling System, by even a small amount, to allow coolant that has been stored in the Overflow Tank to return to the Cooling System as the Cooling System cools, following an Engine Shut Down.

Here's a link to a fairly good explanation and visual of how this happens and why: http://auto.howstuffworks.com/cooling-system7.htm
 

·
Registered
Joined
·
849 Posts
Discussion Starter #8
Thanks for that detailed explanation Bluehighways...
 
1 - 8 of 8 Posts
Top