Removing a drain bolt on a Mishimoto radiator

[y_p_w]

I never really thought of this. I had someone install it for me (charged $80) on my 2004 WRX because it's beyond my mechanical skills. He never installed an aluminum radiator before but said it was no different than a standard plastic tank radiator.

I've been kind of lazy with maintenance, but it's probably about time for a coolant drain and fill. I'm not sure how much coolant I would need since it's a larger capacity aftermarket radiator. Also - I see it's a bolt rather than a petcock like every other radiator I've ever used. Am I going to need a new o-ring? And looking at other discussions it sounds like Mishimoto has gone from o-rings to Dowty seals.

Any tips? I had a look at it when I did an oil change and never really thought of how I was going to do it. It also looks like it will make a huge mess unless I can funnel it somehow with a slow drip. Access also seems to be really limited, although I think I can fit a socket wrench in there.

 

[maxdustington]

Originally Posted by y_p_w
It also looks like it will make a huge mess unless I can funnel it somehow with a slow drip. Access also seems to be really limited, although I think I can fit a socket wrench in there.
Yep. Draining coolant is a PITA but at least you have a drain and don't have to pull the lower rad hose.

 

[y_p_w]

Originally Posted by maxdustington
Originally Posted by y_p_w
It also looks like it will make a huge mess unless I can funnel it somehow with a slow drip. Access also seems to be really limited, although I think I can fit a socket wrench in there.
Yep. Draining coolant is a PITA but at least you have a drain and don't have to pull the lower rad hose.

That might actually be easier than accessing the drain bolt.

 

[Audios]

Sometimes its easier to find a small feed hose and drain it through there. Make sure the cap is off so it doesnt vacuum lock and hold alot in the engine. Sometimes removing the highest hose can help drain most of it out also, like the smaller throttle body hoses or the expansion tank return, just to help it drain.

 

[slacktide_bitog]

Just keep filling it until it's full, then fill the overflow bottle

Whatever seal/O-ring Mishimoto provided should be just fine.

 

[Dinoburner]

HF has a handy vacuum pump transfer set up where you would just draw the coolant by removing the radiator cap. This assuming the cap is on the tank and not somewhere else.

 

[y_p_w]

Originally Posted by Dinoburner
HF has a handy vacuum pump transfer set up where you would just draw the coolant by removing the radiator cap. This assuming the cap is on the tank and not somewhere else.

Two caps since it's a turbo. One on the radiator (I replaced the Mishimoto plastic cap with a Subaru OEM) and one on the upper tank.

 

[SZR48207]

Originally Posted by slacktide_bitog
Just keep filling it until it's full, then fill the overflow bottle

Whatever seal/O-ring Mishimoto provided should be just fine.



This works. On my Triumph motorcycle, I can basically fill the radiator, and then fill the overflow tank, and the "level" will set automatically because the coolant will heat up and expand and spill out of the overflow tube once it's at the right temp.