The Honda PCX / Forza / ADV150 / SH Forums

I'm wondering about how to tell if the coolant level is OK. I thought I read somewhere that the level in the reserve tank should be on the low side when the engine is cold and on the high side when the engine is hot. Can anyone confirm this or ...?

When the engine heats up, the coolant in it's system expands and flows into the reserve (overflow) tank and so the level in the overflow tank will rise a bit. As the engine cools after a ride, the coolant contracts and flows back from the overflow tank into the coolant system.

Keep about 2" or so in the overflow tank when the engine is totally cold and you'll be OK. Don't let the overflow tank become empty because it means air will be sucked back into the cooling system when the engine cools. You can't overfill the overflow tank because any excess will simply be expelled out thru the tube at it's upper level; so any excess is simply wasted, it doesn't hurt the scooter.

Are there not min/max marks on the expansion tank?

gn2 wrote:Are there not min/max marks on the expansion tank?

Obvious or sarcastic

How could the marks on the tank be sarcastic...?

gn2 wrote:Are there not min/max marks on the expansion tank?

There are, but very difficult to see unless you use a black marker to show them up, I keep my level (cold) to the top of the clip that holds the over flow pipe to the tank.

thanks for the input... when cold, mine is about a 1/2 over the min mark so I guess I'm good.

The level of the coolant is actually simple... Just keep it between the "low" and "high" marks, when the engine is cold. Even if you little (apr. 1cm) below the "low" mark it is no problem at all (the expansion tank is quite big).

The more important question that I´m asking myself is whether I should replace the coolant or not. According to Honda manual it should be done every 2 years, but it appears to be not a quite simple task, especially the bleeding the air out of the system.

The more important question that I´m asking myself is whether I should replace the coolant or not. According to Honda manual it should be done every 2 years, but it appears to be not a quite simple task, especially the bleeding the air out of the system.

I’m not recommending this for others - but on all my vehicles ( pickup, car, and now PCX) when I change the oil, I also siphon out the coolant from the coolant reserve tank and then refill it with fresh. I figure doing so keeps the coolant fresh longer. I don’t flush the radiators, just keep doing this. I know it might sound wacky but that’s what I do.

I’m not recommending this for others - but on all my vehicles ( pickup, car, and now PCX) when I change the oil, I also siphon out the coolant from the coolant reserve tank and then refill it with fresh. I figure doing so keeps the coolant fresh longer. I don’t flush the radiators, just keep doing this. I know it might sound wacky but that’s what I do.

It certainly won't hurt!

springer1 wrote:

The more important question that I´m asking myself is whether I should replace the coolant or not. According to Honda manual it should be done every 2 years, but it appears to be not a quite simple task, especially the bleeding the air out of the system.

I’m not recommending this for others - but on all my vehicles ( pickup, car, and now PCX) when I change the oil, I also siphon out the coolant from the coolant reserve tank and then refill it with fresh. I figure doing so keeps the coolant fresh longer. I don’t flush the radiators, just keep doing this. I know it might sound wacky but that’s what I do.

Not Wacky I do it all the time especially in my cars and other equipment. Its easy , fast ,and keeps the additives and chemicals fresh without doing a major change especially where they are difficult ie power steering , auto trans etc... which generally comes later when time permits.

springer1 wrote:

The more important question that I´m asking myself is whether I should replace the coolant or not. According to Honda manual it should be done every 2 years, but it appears to be not a quite simple task, especially the bleeding the air out of the system.

I’m not recommending this for others - but on all my vehicles ( pickup, car, and now PCX) when I change the oil, I also siphon out the coolant from the coolant reserve tank and then refill it with fresh. I figure doing so keeps the coolant fresh longer. I don’t flush the radiators, just keep doing this. I know it might sound wacky but that’s what I do.

I do the same for hydraulic reservoirs. Uses the last in the tin from a full flush on other bikes. Saves throwing it away

If you look between the rear wheel and the passenger peg on the silencer side you can get a fairly good view of the level in the coolant reservoir. You don't have to take anything apart. I just took the picture shown below today after about a 5 mile jaunt to get lottery tickets and a view of the shoreline (in between the rain drops). If you look carefully you can see that my coolant level is just below the top guide for that hose (PCX is on center stand). When everything cools down it will be slightly lower. . .about half way between the high and low level marks.

Here is another pic showing the top of the radiator behind the cover. I know you can look at the level through the hole in the panel side but if you just want a quick look without getting to ground level it's an option. Also Homie did a video that is very helpful indeed.