radiator cap

[qship96]

I was checking the coolant level in the q,and as i removed the filler cap{ the one closest to the engine block,NOT the one on top of the radiator,the rubber gasket stuck to the filler neck and ripped! a quick trip to the local infiniti dealer and 13.65 later the new cap was in place.I noticed the cap has a new part number in the computer and no longer has that spring loaded part that hangs down inside,like the original cap-also the old cap was printed" .9 BAR" on it,new one doesnt say this,it is just a cap with no mechanism inside it- anyone know why they made the change and if the new one not being a pressure relief model makes any difference? seems a strange part to re-engineer?

[Q45tech]

The pressure relief cap goes ONLY on rad, the filler neck just gets a cap with rubber seal.

[94 Q45]

Hi, Q45tech, I noticed coolant leaking from the radiator filler neck and I would like to know what might be the cause? Is it because of a bad radiator filler neck cap or maybe an overfill of coolant in the cooling system since the coolant in my reservoir is more than the max level. Thank you for your opinion.

[maxnix]

If it is not the cap, it must be the neck (epecially if the leak is only lower).

[sijoko]

Head on over to Autozone and rent out a Radiator pressure tester. It will help you find the source of your leak. It might be the cap.

[qship96]

check rubber seal ring on underside of rad. cap-I find nissan caps to have a tendency to let rubber seal stick to metal,and the twisting motion of removing the cap tears the rubber- happened 2x to me- the second was to a less than 1 year old cap,removed for the first time -and the rubber stuck and got torn!

[maxnix]

Use some Wurth on the rubber.

[Q45tech]

Part of the every 30 days [at least] examination of coolant level........don't always trust the overflow bottle level.

Important that owners see a few dozen overheats and the resultant total destruction of the engine to fully understand.The pain, the crying , the whailing to a higher being, the blaming of everyone but themselves!

I can always tell by cap who ignores their cars emotional and physical needs.

[94 Q45]

Hi, I change the radiator filler cap and no leak has been found so far and I am just curious why every time when I open the filler cap, a small amount of coolant will shoot out from the filler opening and I noticed the coolant is fill all the way up to the top of the filler neck. Is it because I have too much coolant in the system and is this normal? Thank you for the response.

[Defiant]

That's normal. The system may have a few ounces of pressure still in the system from the last time it was brought up to operating temperature, and will burp. Don't be concerned with ½" or so of airspace in the filler neck when putting the cap back on, it'll purge right out the next time the engine's run.You can't have too much coolant in the system, as it expands out into the overflow tank every time you go out, then shrinks back to completely full as it cools. Any excess coolant -filling the overflow tank above the MAX line- will just leak out the vent in the tank cap. No concerns.

And good riddance to the days when cars didn't use expansion (coolant recovery) tanks.

[Q45tech]

I always squeeze the upper hose to get the coolant level up to the rim as I return the cap, same with the other cap atop rad............which should also be checked frequently.

The 0.9 is 0.9 BAR or 13.23 psi blow open pressure.

When you use a coolant pressure tester you can check at center if you use a clamp to prevent pressure [15-20 psi] from going out thru rubber hose to expansion bottle.

[Meaux]

My cap went south, so I bought a aftermarket SLANT replacement cap w/ spring, put it on and didn't check it for awhile. The SLANT cap allowed coolant to end up in the valley, so I ordered the Infiniti part. eventually the coolant poo-pooed my knock sensors...Plenum Job!!!Allways buy the Infiniti cap...Lesson learned.