cptpain

iTrader: (1)

my cooling system is going to be serviced not only cause i just bought my car but because coolant doesnt get sucked back in the motor and the thermostat is an aftermarket at 180* and it does get pretty cold in texas and the heat doesnt work too well cause of the colder t-stat.
im not deducing the fact that i may have blown coolant seals but i need to at least go step by step before i start making assumptions.

i know that FC has 2 rad caps. and they are all in different places from year, trim.
mine is a GXL and has a cap on the thermostat housing and another in line with the overflow bottle. my question is are both caps the same pressure cap? or is the overflow one not a pressure cap? because from my understanding is that the one inline with the overflow is not a pressure cap.

i already bought a t-stat from mazda and i need to know if the two caps are the same and if not what the part numbers are so i go order them from mazda.
the parts guy told me they were the same part number and even showed me the diagram but im not convinced.


and one more question... why cant i just get rid of the second cap and run the little coolant line directly to the cap on the overflow bottle?

87 t-66

iTrader: (133)

mazdatrix.com

NZConvertible

180degF is actually the correct opening temp for the FC's thermostat, but it should definitely still be replaced with an OEM one.

Only S4's have two caps (S5's have one), and they're lucky for it. They're always in the same two places though. Early S4's had the overflow hose on the thermostat housing; later ones have it on the radiator.

You're right, they are NOT the same. Only one is a pressure relief cap (the one with the spring arrangement underneath), and that goes wherever the overflow line is. The other cap is just a plain cap. You can use a pressure relief cap on both, but it's a waste of money because without an overflow line it'll do nothing.

He's wrong. Mazdatrix have both caps here, or you could try one from a local parts store. I've had no problems at all with a non-OEM pressure relief cap from a respected brand. You don't need to replace the plain cap unless it's leaking or the rubber is cracked.

Having a cap on both the radiator and thermostat housing makes filling and bleeding the cooling system easier. There's no point in getting rid of one of those. The overflow line should run from the bottle to whichever fill neck has the nipple for it, and that one must have a pressure relief cap on it.

cptpain

iTrader: (1)

thanks a bunch man.... yeah i had a brain fart i completely forgot about mazatrix. you're very much helpful