Heater hose replacement options

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Heater hose replacement options

Post by Lock » Tue Oct 22, 2019 12:11 am

Wanted to make an easy to find post about heater hose options.

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The steel heater hose tube under the manifold is likely rusty after 40 years even in a well-maintained car, as of Oct 2019 they list at around $250. I've found a reasonable replacement - e28 heater hose parts, which are:

11531272866 Distribution Tee
11531274210 Water Hose (to water pump/t-stat housing)
64211368715 Heater Hose (from car heater/firewall)

All of this cost me around $30 before shipping

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As you can see it all lines up. The reservoir outlet is within range as well (notice on the old one how far down the reservoir hose goes).

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There's is one catch - it doesn't have any provision for the small hose for throttle body heater/idle speed unit. I didn't need either on my project, so I just blocked off the block barb and was done. This however leaves two options for standard setups;

1. Block it off completely, deal with the idle controller and temp sensors.

You'll need a bolt for the block hole, use a M10 1.5 thread and a copper washer (spare oil filter washers work well).

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You can bypass the throttle heater especially if you don't drive in snow, it's not included on the e28 or e34. If you have the mechanical idle air controller, you can convert to an electric one (don't have to have the specific BMW model, most adjustable bimetallic strip idle valves that fit the hoses will do the same job particularly Japanese models of the same era), and link it up to the fuel pump power line as the 1980-81 models do.
This idle controller also houses the temp-time sensor for the cold start injector and engine temp sensor, you could buy a generic radiator hose adapter with the correct size threads, cut a section of hose and install it, and screw them in.
Or buy a new t-stat housing, they currently run about $40, they generally come with four threaded holes to suit all models so by extending the wiring you could move them up there.

2. Keep the t-body heater/idle hose and re-route the output.

The easiest thing to do here would be to use a T-piece to connect it to the radiator/reservoir tank overflow hose which is the same size.
Another options could be to cut the heater or coolant hose and insert a radiator hose adapter that has a thread you could then screw a hose barb into.

The original part is still available and will obviously be a drop-in replacement, but there are other options if you're willing to get creative.
1979 528i 5-speed conversion G260/6
1980 Honda CX-500

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