Reservoir tank empty

[rick-pcx]

Good morning, I have a honda pcx (125) and I live in Spain where these days it is very hot (30-35ºC). The bike is less than 1 year old and 5,000 KM.

I checked the coolant reservoir as a routine, and saw that it was even below the minimum mark. The bike did not heat up or cause any problems.

I refilled it (although I've passed the MAX indicator a bit) waiting to see what happens.

I checked it last week and it was half. Is it possible that due to a momentary tº rise of the bike (because it is really hot in my area and sometimes I accelerate a lot) that has happened or is it a defect? Anyone else has happened?

[springer1]

You’re fine as long as it’s not below the minimum line when the engine is cold. If you over fill it, the excess will just expand out the overflow tube when the engine gets hot - no problem.

[rick-pcx]

You’re fine as long as it’s not below the minimum line when the engine is cold. If you over fill it, the excess will just expand out the overflow tube when the engine gets hot - no problem.

Hi, thanks for your reply. I think exactly what you are saying is a problem.

When I realized that the reservoir was below low mark (far below, I had to shine a flashlight to see some coolant at the bottom of the reservoir), the engine was hot, not cold.

I deduce that it is quite bad news because when the engine warms up the reservoir fills up, and when it cools down it empties a little.

But I noticed when the engine was hot.

I'm not sure what happened, last week it was half. Is it possible that with the heats it has evaporated enough?

Regards

[OldGuywhoTinkers]

I pay attention to the following: are there leaks ? Check during the first five minutes after you stop the scooter. The scooter should have a radiator cap in good condition over the radiator. With enough light, when cold, carefully unscrew the radiator cap. The antifreeze should come out or be full in the mini radiator. Check the reservoir tank. When stored, it is possible to get bubbles in the system, but they will move to the highest point and essentially disappear during normal use. Use premium antifreeze when topping off. I prefer the red Toyota antifreeze. I wouldn't mix them UNLESS the antifreeze bottle says it is safe to do so.

[springer1]

You’re fine as long as it’s not below the minimum line when the engine is cold. If you over fill it, the excess will just expand out the overflow tube when the engine gets hot - no problem.

Hi, thanks for your reply. I think exactly what you are saying is a problem.

When I realized that the reservoir was below low mark (far below, I had to shine a flashlight to see some coolant at the bottom of the reservoir), the engine was hot, not cold.

I deduce that it is quite bad news because when the engine warms up the reservoir fills up, and when it cools down it empties a little.

But I noticed when the engine was hot.

I'm not sure what happened, last week it was half. Is it possible that with the heats it has evaporated enough?

Regards

It could be that the coolant level inside the engine was also bit low the first time the overflow tank was emply. Then when you filled the overflow tank and ran the engine until hot - some of the overflow fluid was sucked back into the engine to fill it back up as it cooled down. If so, it worked as designed. Hence your engine is full of coolant and your overflow tank is now lower with the engine cold than when you first filled it.

If I were you, I'd keep watching the level of the overflow tank. The level should rise with the engine hot and drop again as it cools. If those two levels stabilize and do not continue to drop, it means the engine is now full of coolant and the overflow has a proper amount of reserve fluid as well. So just maintain it between Min & Max with the engine cold. But if A) the coolant temperature warning light comes on or B) the overflow coolant levels do not stabilize and continue to drop or C) if you detect fluid on the floor from a leak, then I'd start trouble shooting further because you may have a coolant leak.
.

[rick-pcx]

Hello everyone, thanks for the responses. I tell you a little about the situation.

@OldGuywhoTinkers @ springer1 after 5 minutes there are NO floor leaks. I cannot unscrew the radiator cap because it has a plastic protection and I would have to remove the right-side protection; When I can I will do it, although I hope not to break anything. Now after 30KM, the reservoir is still at level. I have also observed that the hose going from the highest point of the radiator (the one going to the reservoir) is hot when the engine warms up. That said, I deduce that the radiator DOES have an adequate amount of coolant because otherwise that hose would not be hot, if I'm not mistaken.

I've thought about what you say about the air bubbles in the radiator but ... at 5,000KM wouldn't it have given him time to get out? It must have been a bubble large enough to leave the reservoir almost empty.

After doing 2 laps (yesterday and today) with a lot of heat and doing 15KM each time, I notice that the level in the reservoir remains stable.

It will have been somewhat punctual although I have been scared enough because I know it can go down a little but not to leave the tank almost empty.

That said, I will continue to observe it, and since in 1,000 KM I have to take it to the dealer to do the review, I will comment at least for them to write it down.

[Old Scoot]

.......That said, I will continue to observe it, and since in 1,000 KM I have to take it to the dealer to do the review, I will comment at least for them to write it down.

You should have gone to the dealer to begin with, the scooter, is as you say:

....... The bike is less than 1 year old .......

The bike should still have warranty, I have two years on my 2020 Forza 300

I checked the coolant reservoir as a routine, and saw that it was even below the minimum mark. .......

Was that with a cold or hot engine? with a hot engine this wouldn't be good.
I normally would top of coolant when the engine is hot so I know that the level is ok, unless there are any leaks.

[Mel46]

I had a problem like that on my 2013 PCX so I started looking closely at the lines and connections. What I found was that the overflow reservoir had a crack in the neck area where the line connects to it. I know that the newer bikes are set up a little different than my 2013 model, but it is worth a look to make sure.

It looked fine so I grasped the rubber hose close to that connection point and wiggled it lightly. That is when I saw that the neck was cracked. It happens from old age and heat. The reservoir is cheap to replace if it does have a problem at the neck...or you can glue the cracked area back together with a high heat glue. (I have no idea if superglue falls in that category.)

[rick-pcx]

I checked the coolant reservoir as a routine, and saw that it was even below the minimum mark. .......

Was that with a cold or hot engine? with a hot engine this wouldn't be good.
I normally would top of coolant when the engine is hot so I know that the level is ok, unless there are any leaks.

Hi, it was with hot engine. Actually I drove 30 KM (after refilling the tank) and at the moment it still at the mark.

I don't know what happendes. The bottle it doesn't have any crack,