Tuesday, September 30, 2008 - 03:13 pm, by: Piers McDonald(Drp)
So a couple of months ago, I decided to give the cooling system a bit of an overhaul. I got a TRD 1.3 bar radiator cap, some nice new hoses, and filled her up with some red coolant.
After a week, my engine bay was pink, and I'd lost half my coolant. The coolant was seeping through the layers of the hoses under pressure. I tried tightening the clamps, and that seemed to work, until yesterday. I returned to my car after only having just driven it to find that the top hose had blown off and taken part of the top tank with it.
I should add that the hoses I got are garbage, they are blue aftermarket autopro hoses, and I've never seen this kind of leaking before. Also, the bits that broke off the top tank were very brittle and broke apart in my hands.
So my question is, should I even be using a 1.3 bar radiator cap? Is this kind of pressure necessary, or even desirable? I don't think it's letting enough pressure out and is making my system a little hotter than it should be.
I've got a digital temp gauge and I've been reading 97º with normal city driving, climbing to 104º after some spirited hilly country driving. But when I stop the engine, it climbs up to 114º!
I think my system would have been quite OK with a 1.1 bar cap, but I felt like spoiling my baby. After all it's her only TRD part.
Tuesday, September 30, 2008 - 05:26 pm, by: Scott Casey(V8soarer_1991)
as far as i know there are only 2 types of coolant pressures in cars 0.9 and 1.1.
the cars are only made to have those pressures for a reason. and if you go over the RECOMMENDED pressure you start blowing water pump seals and hoses like you have. unlucky for you it blew the tank "plastic not metal" and not a hose. could have been a water pump.
Tuesday, September 30, 2008 - 06:17 pm, by: Piers McDonald(Drp)
Well costly it was. $693 all up Just returned from the radiator man, and I now have a shiny new top tank and a freshly flushed system. My top tank was bound to fail sooner or later and I'm glad to have flushed the system as it was pretty blocked apparently. But this leaves me wondering why 1.3 bar rad caps are advertising as improving cooling flow and cooling capacity without any warning about what cars they might not be suitable for.
Now of course after visiting any mechanic I have to fix what they broke, my turbo timer is now throwing an error, how could a radiator service effect my turbo timer?!?
Peter Nitschke Junk Filterer South Australia UZZ30 UZZ31
Tuesday, September 30, 2008 - 06:27 pm, by: Peter Nitschke(Pen)
When you think about it, a higher pressure radiator cap won't improve anything. It can't make things run cooler, it can't dissipate more heat.
Most likely your tank was going to blow anyway, and as you mention, the hoses might be dodgy, so it might be "safe" if everything is in good condition, but it's still not achieving anything.
Ben Socratous Goo Roo SA I am the fibreglass/kevlar/carbonfibre king!
Tuesday, September 30, 2008 - 09:20 pm, by: Ben Socratous(Socrates)
Piers McDonald wrote on Tuesday, September 30, 2008 - 06:17 pm:
But this leaves me wondering why 1.3 bar rad caps are advertising as improving cooling flow and cooling capacity without any warning about what cars they might not be suitable for.
1, as it is a toyota RACING development item, it will say somewhere on the pack about not being intended for street usage. If you go to an australian toyota dealership and order trd parts through them, they make you sign a waiver acknowledging that there is no warranty on the item, you are not covered for any damaged caused by that item, and it more than likely isn't ADR legal.
Obviously a radiator cap isn't going to get you a canary, but think about it like Scott said, the stock system is designed to handle stock pressures. I've seen cars in the shop running upwards of 3bar water pressure, but they also had a completely sealed system (ie no venting caps), a huge custom alloy rad and about $45k work of engine build! lol
I know its a bit of a stretch, but think about it akin to slapping a T88 on the side of your block with no supporting mods done. If your rad hoses sisn't go, then the heater hoses probably would have.
Raising the cap pressure serves only to raise to boiling point of the coolant. But if you're getting the coolant that hot to warrant a higher pressure on effectively a stock motor, you have some issues somewhere!
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