Cooling system runs at 2 bar, thoughts on 1.4 bar?

[J.Belknap]

I would recommend leaving the system as is. And don't overfill.

.02

[JCL]

Originally Posted by J.Belknap

I would recommend leaving the system as is. And don't overfill.

.02

If we go back to basics, the cap release pressure isn't what the system is running at, but rather when it vents. The highest temperature is probably during a heat soak after a hot shutdown. If the system can't handle 2.0 bar without rupturing, I suggest it should be fixed. Putting a 1.4 bar cap on there is a band-aid solution to a separate problem, either that the vehicle is overheating or that one or more components are aged and weak. All you are doing by using a 1.4 bar cap to avoid the problem is delaying it happening. How many leaks are there that won't happen at 1.4 bar but will at 2.0 bar?

And why risk the chance of having to top up the coolant more frequently due to occasional venting from using a lower rated cap? If all vehicles were having this problem in the first year after product release then there would be reason to consider if there was a design problem. But if it is first happening when the same vehicles are ten years old, then it is a maintenance issue. Just fix it right. My $0.02.

[Ricky Bobby]

Agreed JCL and like I was telling slick, I don't just recommend slapping a lower bar rad cap on a ten year old cooling system and doing nothing else.

I'm more along the lines of when a cooling overhaul is done, and relevant parts, hoses, Tstat and water pump etc is replaced, and the coolant is flushed and refilled, then if you so chose at that point to replace with a lower bar cap then you can do so with most likely no different operation or ill effects.

I agree with you that the system must first be fully operational, coolant levels correct, etc, before worrying about what cap to go with

[JCL]

It just seems misguided to me. If I had a tire that had a slow leak at 30 psi, I wouldn't consider it to be a reasonable solution to run it at 20 psi. Even if it did hold that pressure without dropping further.

[SlickGT1]

LOL. No. I don't plan on just replacing the cap with a 1.4. I fully plan on fixing it with the regular cap. I am just curious to see why we have a 2 bar one.

[Ricky Bobby]

So you're sticking with the 2 bar stock cap Slick? I don't think the 1.4 bar cap would give any ill effects, as like Doru said, unless you have some issues where you are overpressurizing the system often enough to be losing coolant, then you probably have other cooling issues. However, with the 2 bar cap I am almost certain you'd be venting less because of the higher pressure, whereas you are more likely to reach the 1.2/1.4 bar pressures in normal operation on hot days etc, and it might be venting more often, which might require additional coolant on more frequent occasions than the stock cap. Personally I have not had to add coolant since I bought the X in 2 years, and I'm ok with that.

I will admit it is funny about the misconception of how the tank cap works, especially in the discussions on BF and the like, most think that it actually lowers the normal running pressure of the cooling system which it does not do at all.


Regardless, I'll be sticking with the stock cap until I have to do some cooling system replacement items and a flush (probably in a year), and normally i'm a "if it aint broke don't fix it" kinda guy, so I might end up with just the same 2 bar cap when I do replace it someday anyway.

[SlickGT1]

No I will put on the 1.4 bar cap for sure. I will just find all the weak links in my system with the 2 bar. I think it is worth a try.

[Ricky Bobby]

Sounds good man I'm hoping you find your leaks and glad i was able to find "our style" cap in 1.4 bar for you, when i do my cooling overhaul next year I'm sure that will be part of it.

[J.Belknap]

Glad you found the leak! That test kit comes in handy eh?

Just throwing this out there..... if the 1.4 bar relief cap doesn't operate under normal conditions, it will not help the system stay sealed any more than the 2 bar cap. If it does operate under normal conditions, it is not rated high enough for the system. A certain relief cap will not raise the MTBF of hoses / seals / expansion tank / etc. It is unrelated.

[giodog2000]

reviving an old thread (sry)....

I'm about to change the Expansion tank and was curious to have some feedbacks on long-term testing of the lower BAR caps.....

Should I stick with the original 2bar or go with the 1.4bar?

Thx!