heater core hose coupler

[erikv11]

Sure I see your point, pros and cons to doing it either way, I can understand some will prefer to keep the coupler.

But just to make sure people understand what we're talking about here, this has been posted about a lot so I am not going to go through the procedure here but: in doing this "elimination" you don't end up with anything approaching a HUGE hole in the firewall. Just little slivers of space.

You gut the coupler so the heater hoses pass through the existing holes in the coupler. It ends up leaving like 1/8 inch space around each hose. I never sealed up that small space and have never noticed any fumes, or cold air etc coming into the cabin.

[Thunderbox]

I have to agree with Erik on the fit. The hose I used fit almost perfectly through the coupler. There was almost no discernable gap. I probably have more gap in the door seals. Plus a teenage son who emits more fumes than any 20 Valve Turbo.

[mc4457]

So its 5/8 " heater hose two of them how long? You hose clamp them to the heater core pipes then to the engine hoses or to the metal nipples on the engine and the exhaust pipe area?

[Thunderbox]

I had to measure to fit. I cut the pipes going to the core. It left two small pipes just past the cross bar. They are now loose so mark before you cut so you can remember which is which. The connection to the core was attached very loosely at first. then pushed hose through the coupler out to the bay and lined up the hose and marked after looking to see if I had enough on the engine side to hook up the metal nipples. You have more play in the engine bay. Once everything looked good I dropped on clamps and tightened everything in the pass comp then made the connections in the engine bay. Ask if you more info.

[erikv11]

The old passthrough is a real nice size for the 5/8 heater hose I used.

The only thing I might change if doing this again, is use a lower quality hose. I used Gates Green Stripe and due to stiffness it is difficult to work with in the tight cabin space under the dash. But fits almost snug in the emptied out passthrough. Any 5/8 heater hose will work unless you are asking it to do bends, then be careful it does not fold.

The 5/8 hose will fit perfectly on the metal pipes (cabin side), then you can either hook it to the hose nipples in the engine bay, or run it all the way to the block. You'll have to measure to fit, depending on which method you use. I think easiest is to go to the hoses, then you need maximum 3 feet total, you will have some left over.

[mc4457]

so the hoses at the core have to be cut off? It's not pipe clamp?

[erikv11]

This will be obvious once you get in there or read a tutorial about replacing the heater core but: there are no hoses inside the cabin. From the outside (engine bay) to inside (cabin), the original setup goes

engine - has pipes that heater hoses slides over
heater hose - each has a metal nipple
coupler outside - nipple fits in coupler with retainers and o-rings
coupler inside - more o-rings
aluminum pipes - nipple fits in coupler with retainers and o-rings
pipes hook to heater core, again more o-rings

I was talking about cutting off the aluminum pipes, so they are shorter about half length, so that it is easier to work in there. You hook the 5/8 heater hose to the pipes. Don't make them the same length, though, you want offset so the hose clamps you put on do not run into each other.

[mc4457]

Thanks everyone for your help. I received the coupler from fcp and after getting the old one out and reading all the posts decided to do it the easy way and run heater hoses through the firewall. So far no leaks, but I think I'll fill the void in the firewall with expansion foam. Now, if only I could get the vacuum lines hooked up right and the damn thing running well in idle, I can die a happy man.

[abscate]

I found replacing the factory coupler simple and easy when I did my heater and AC evap core replacement so I stayed stock.