Heater Drains

[Paul & Dolly]

I cleaned out the heater drains today - they were clogged..

There are excellent instructions in the Tech Manual at the end of the Drains section.

Here are some pictures

Paul

[ja17]

Be careful, as the drain hoses under the dash are not re-enforced rubber. They get old, dry rotted, brittle and can become very fragile. Be prepared to replace them they may not survive the cleaning.

[280sl1968]

Agreed on the condition of the rubber pipes - if there was debris blocking the drains, it is quite possible they have been blocked for some time and the rubber will have deteriorated with age. Mine had, and while it is a beast of a job to get under the dash to take them off, it was well worth it as they were badly perished and it let me properly check the condition of the lower metal drain tubes that pass through the firewall.

I replaced mine with some black silicone tubing which I found easier to fit than the rubber hose.



David

[pj]

Perfect example of a topic in the Tech Manual that needs to be edited comprehensively. Someone who knows what's underneath and inside will recognize the words that are used but I don't know what "lower metal drain tubes" are, what they look like, where to find them, or even how many of them to expect. Pictures are a great help, especially for orienting me. Some day if we could shoot some decent video, that would be even more helpful.

[280sl1968]

Might be my poor description too. It took me a while upside down on the driver's seat with my head in the footwell to follow the path of the drain from the air intake to the engine bay.

The drains from the air intake cavity start as metal tubes which pass into the driver and passenger footwells on each side. There is then a flexible rubber hose (approx 20 cm in length) attached to those that continue the drainage pathway inside the car and attach to metal tubes again lower down which then pass through the firewall into the lower part of the engine bay where any water drains out. It is the latter metal tubes that I call the "lower metal drain tubes"

The rubber hose essentially connects the upper and lower metal tubes and it is this rubber hose that should be checked for condition and replaced if necessary.

You may also find that the lower metal drain tubes are blocked. Unblocking these is easier with the rubber hoses removed. Check the condition of these lower metal tubes too as they quite often are corroded.

If you have never checked these drains on your car, I would highly recommend doing so. It is something I left on my to do list for way too long and when I finally got round to it, I'm glad I did. There was about a half inch of crud in the bottom of my air intake cavity and the drainage holes were buried. Fortunately when I cleaned it out, the metal was in good shape under there, but the rubber hoses were completely perished.

David

[Paul & Dolly]

I had already checked the rubber connecting hoses inside the car, and they look relatively new, probably changed by a previous owner.
The bottom of the  air box was covered  with "silt"  so the drain entrys were not visible - I gently rodded , brushed and then flushed them through, and all seems fine now, with a good flow through to the engine compartment.

Paul

[pj]

David, I didn't mean to come across unappreciative. It's mighty uncomfortable trying to check anything under the dash, I know. There's always a little bit of water in my footwells when I get caught in the rain, so I need to follow the procedure have described. Thanks for that.