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-   -   Replacement Heater core options (https://www.rx7club.com/interior-exterior-audio-26/replacement-heater-core-options-1172370/)

Kish’s Garage Jan 26, 2026 12:54 PM

Replacement Heater core options
 
I am looking into replacing my heater core as in late fall it started leaking profusely before garaging for the winter. The factory part is no longer available and so far this from Brassworks seems to be my best and only option for a replacement. Does anyone have experience with these heater cores and this job that could attest to their quality and perhaps give a few tips to a newbie like me?

The Brassworks FD heater core

fesus Jan 26, 2026 03:39 PM

I’ve seen a few people run Brassworks heater cores when OEM is no longer available, and overall the feedback is mixed but generally decent. The build quality is usually solid since they’re brass/copper and made to order, and many folks report no leaks and good heat once installed. That said, some have mentioned heat output not being quite as strong as OEM and recommend being extra careful with installation and bleeding the system. For a first-timer, definitely flush the cooling system thoroughly, take your time during the install (dash work can be tedious), and make sure all air is properly bled afterward. If OEM truly isn’t an option, Brassworks is usually considered one of the better aftermarket choices.

Trout2 Jan 31, 2026 03:36 PM

Have you confirmed the core is the source of the leak. I mention it since there are o-rings in the two lines that pass through the firewall.

Jack

Kish’s Garage Feb 2, 2026 07:11 AM


Originally Posted by Trout2 (Post 12648052)
Have you confirmed the core is the source of the leak. I mention it since there are o-rings in the two lines that pass through the firewall.

Jack

I have not yet. I wouldn't be surprised if the O rings have hardened and are leaking. Is there a good method to check this prior to pulling my whole dash out?

Pete_89T2 Feb 2, 2026 08:32 AM


Originally Posted by Kish’s Garage (Post 12648190)
I have not yet. I wouldn't be surprised if the O rings have hardened and are leaking. Is there a good method to check this prior to pulling my whole dash out?

Perhaps, if you can find a way to visibly inspect the pipe joints where the O-rings are located, and then pressurize the cooling system with a coolant system test kit, that should easily confirm the source of the leak. I'm thinking you'll need to remove some of the easy stuff (glove box/trim bits) and maybe some of the not so easy stuff (A/C evaporator core, HVAC blower) that's in the way, get some good lighting in there and use a flexible inspection camera or perhaps some small inspection mirrors to see what's going on? The coolant system pressure test kits are usually available as a free rental from most major auto parts retailer chains.


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