Datsun Man
Member
This is going to be a helpful tip for anyone that has a standard type radiator cap on their vehicle. I don't care what manufacturer you have as it should apply as long as the cap isn't a weird plastic one like what GM and Ford use.
Now this is something that I got to learn a while back when working at a Nissan Dealership. I was chasing a Engine Over Heading problem for a week and was getting my ass kicked! Finally I ran across a Technical Service Bulletin by Nissan(unfortunately I can't remember the number) that brought up the Radiator Cap. Well today I will show you a good example of what to look for and this particular one is from a Hyster Forklift.
In the first picture below you will see the rubber seal on top(technically the bottom of the cap) all swelled up. This is a normal thing that happens over time. When it does this it will expand around the metal part above it(or below it in this picture).

When it does that it will look like this when you look from the top(technically bottom of the cap). You will not be able to see that metal part what so ever. If that is the case it is considered faulty and can't do the job it is intended for.
Now what you want to see is what this new cap is like. As you can tell the rubber is not swelled at all.

Here is what is looks like when looking directly at it. Notice how you can see the metal part on the sides a bit.

Now if you are doing a once over on the vehicle, I would definitely recommend checking that out. Radiator caps are much cheaper than a damaged engine and you can usually get them at any Auto parts store.
Hope this helps many out there!
Now this is something that I got to learn a while back when working at a Nissan Dealership. I was chasing a Engine Over Heading problem for a week and was getting my ass kicked! Finally I ran across a Technical Service Bulletin by Nissan(unfortunately I can't remember the number) that brought up the Radiator Cap. Well today I will show you a good example of what to look for and this particular one is from a Hyster Forklift.
In the first picture below you will see the rubber seal on top(technically the bottom of the cap) all swelled up. This is a normal thing that happens over time. When it does this it will expand around the metal part above it(or below it in this picture).

When it does that it will look like this when you look from the top(technically bottom of the cap). You will not be able to see that metal part what so ever. If that is the case it is considered faulty and can't do the job it is intended for.

Now what you want to see is what this new cap is like. As you can tell the rubber is not swelled at all.

Here is what is looks like when looking directly at it. Notice how you can see the metal part on the sides a bit.

Now if you are doing a once over on the vehicle, I would definitely recommend checking that out. Radiator caps are much cheaper than a damaged engine and you can usually get them at any Auto parts store.
Hope this helps many out there!