1.3bar coolant cap - good or bad idea?

[Rob Rohr]

I am trying to enhance the cooling system on my 1G and am thinking of buying a 1.3bar coolant cap. Is there any reason not to buy one of these? I have all new hoses, new rad, H2O pump, etc so I am not worried about a bit more pressure. Will the higher press cap help a bit?

 

[Staytuned]

Yes, higher pressure cap = higher boiling point, which means good.

 

[heavyD]

The higher pressure will help especially if you have a FMIC but if your hoses aren't in perfect condition they will leak. In my experience the hoses for the turbo coolant inlet/outlet are the ones that seem to leak the easiest so you would want to put a stronger clamp on those hoses (if you have a watercooled turbo).

Also you should try a mix of 50/50 of coolant & water or less if you live in a warm climate and add a bottle of Redline water wetter.

 

[Bohrn]

yes the extra pressure will keep it from boiling.

Buuuuut.... if you have any weak points(not just hoses) at all it will leak there. And possibly more than leak, but burst. If you have a welded radiator like a fluidyne, that should be ok, but remember your coolant goes thru your whole engine and your heater core as well. Lots of small passages (oil cooler) and its an old system.

 

[Defiant]

I'd not go higher pressure on a radiator with plastic tanks.

Go to 30% antifreeze- get one jug of premixed, and top it off with distilled water from the grocery store and you'll be about right..

 

[logic]

I'd not go higher pressure on a radiator with plastic tanks.

Anecdotal evidence of this: we switched from an old cap that couldn't hold any pressure at all to a new 1.3 bar cap. A few weeks later, the end of the (original plastic) radiator top-tank inlet blew off as a perfect 1/2" ring, after a few instances of the upper hose blowing off.

Those plastic end-tanks, especially the ones on a 13-15 year old car, are weak, especially where they've seen any amount of clamping force over the years.

Other weak points to consider: head gasket, hoses, hose clamps, water pump, thermostat housing (or any of the other thin-walled cast pieces in the coolant system), etc. Something to think about, anyway.