Radiator Cap Question (HKS Radiator Cap= NOT COOL!)

[HKS_TRD]

Basically I put my new HK$ Radiator cap on which is a 1.1 bar item as opposed to the 0.9 bar stocker.
Worked fine whilst driving, held pressure in top hose and still allowed coolant to pass into the overflow bottle.
However upon cooling down rather than sucking coolant back into the radiator from the overlfow bottle the top radiator hose has been sucked in. In my thinking this must mean the return valve on the radiator cap must be faulty. There was an awful lot of vacuum and had to really apply alot of force to prise the cap off. I guess I know that my cooling system is completely sealed!

So the main question is seeing as its a higher pressure cap does the return valve also need higher pressure ( I would have thought not) Now it is definately the right cap, there are only two types for Toyotas and the wrong ones do not fit at al and if you forced it on do not hold any pressure at all whilst driving

[allencr]

Bad cap, replace it.

[Mr Revhead]

actually it is possible to fit the wrong cap, and theres at least 4 types for toyotas.
2 large, 2 small

why did you fit a 1.1 cap? was the stock one causing problems? if so , why?
sounds as if that HKS one is the incorrect one.
i think youd be best to just use a stock genuine one.

[PitStop]

or you could just get a TRD one, im pretty sure they make them? dunno if they're bar ratings are different though

[Mr Revhead]

yes TRD do them
in 1.3 and 1.5 versions

but for a stock/ish road car... you dont need one.
infact unless your cooling system is 100% they can cause issues with the increased pressure.

[celicaboy_2000]

They look good

[Ben Wilson]

Compare the cap with your original one, is it the same height?

[HKS_TRD]

Hi guys. OK I'll be honest I bought the cap purely because it looks good, not just the sticker but the chrome finish. I got the HKS one because it had the closest pressure rating to stock. Re the comment of four different cap sizes for Toyotas as far as I know TRD only do 2 different cap sizes. I have compared to the cap to a factory one and it is the same height.

[oldcorollas]

can you take a pic of the underside of the HK$ and the stock cap?

[EldarO]

might just be a bung cap.

it might be the right one, but just a broken one

my MA70 and JZA70 rads use a different cap, im certain i had to use a different cap to both of them for my liteace, so theres more than 2 types.

Elmo.

[HKS_TRD]

OK well I tested the overflow bottle hose and no leaks. I will get a pic up shortly but besides the Red seals the HKS looks identical to the stock one on the underside

[Mr Revhead]

yeah i was talking about genuine caps..... 2 sizes, 2 different valve types.

TRD do 2 sizes. one in 2 differeing pressures

[HKS_TRD]

OK well here's a pic, the HKS one has the read seals, sorry about the phone quality pics!

[HKS_TRD]

might just be a bung cap.

it might be the right one, but just a broken one

my MA70 and JZA70 rads use a different cap, im certain i had to use a different cap to both of them for my liteace, so theres more than 2 types.

Elmo.

I recall my MA-61 having a different cap to my MA-70 and JXA-70s but that was way different, the MA and JZA ones look pretty similar from on top but different undeneath, one is more shallow. All the aftermarket caps I thought were only made for the later 2 styles of radiator caps not the older (much larger diameter) ones

[EldarO]

thats what i thought too, until i looked throught the catalog, bought the MA70 one, went back and bought a camry one, which fit, just didnt work properly (wasnt letting enough pressure out, blew a hose off) and went back a third time, didnt look at the catalog and picked out the one that looked close enough, im not entirely sure that one even works :/

Elmo.