Is there an OEM coolant fluid that you have to buy for an accord or u could just use any kind? I have 95 accord

 

Use any kind, 50% coolant, 50% water.

 

Generally not a good idea to mix coolant types--i.e., the red and green types. The result can be sludge buildup in the radiator/engine that ultimately causes overheating.

 

They're using all kinds of different anti-corrosion packages. Many of them are bad news when mixed together. Silicates, organic acids, who knows what else... And there's even some with similar colors that are incompatible with each other, so you can't just go by the color.

It's getting more important to know exactly what type is in there, so you don't add something that's incompatible. If you don't know, then drain-fill a couple times with distilled water, than add whatever you want, and make sure you remember what it was when it's time to add some.

Honda says don't use coolant that has silicates in it.

 

https://honda-tech.com/zerothread?id=597103

 

What happen if We put the the coolant to the reservoir tank without mixing it with water ?
I did that a month ago , it was only half of the reservoir tank
Is it gonna cause problem in my engine in the long run ? thx

 

I don't think that is enough to ruin anything....

I would flush your system out completely and start all over again

 

Putting the same type antifreeze into the overflow reservoir will not make any difference whether diluted or not. It's only when you add a different type of antifreeze that you have a potential problem. If you used the same kind, you won't have a problem.