Mercedes-Benz Ponton
Heater Hose Replacement
(using rubber boots)

Here is a simple way to replace the flexible rubber hoses that connect the heater/blower fan to the intake duct on a 1953-1961 Mercedes-Benz Ponton sedan. I recently priced out new hoses from the dealership, then found this $16.00 alternative — and the math convinced me to go with this, the more practical solution. If your heat delivery hoses/boots are dried out and deteriorated, this is a do it yourself method that only takes about an hour per side to complete.

First, remove the old, 7" outside diameter (O.D.) rubber hoses from the car, then clean all the outside surfaces of the fan, duct, heater box, and do any paint touch-up while these parts are on the bench.

Photo 1. Old dried hose

I purchased a pair of inexpensive women's insulated rubber rain boots (size 8) at a local store just for the rubber replacement on the Ponton, and they worked quite well. This rubber also affords decent sound deadening, and provided an airtight seal. They proved to be just as good as the expensive OEM replacements.

Photo 2. Woman's rain boot (size 8)

Check whatever boots you purchase for being the correct outside diameter by measuring the boot at the top pressed against a flat surface — like the floor in a shoe discount store. The required length is between 7 ¼" and 7 ½". Once you find the proper boots, place one on a flat cutting surface and press the rubber flat using a 2 ft. level, or similar heavy straight edge. Cut 7" of the upper part of the boot. This will seem to be an unnatural act, but follow through with it. On the pair I chose, there was minimum taper from the top to the heel.

Photo 3. Measuring the O.D.

Photo 4. Cutting the boot

From here, stretch the boot around the fan housing, and slip it up about 2". Start the cut end of the boot onto the fan, and save the factory-top edge for the stationary intake duct. Use a screwdriver with a blunt tip so you don't damage the material. Don't drop the fan, they are rare and expensive. I found the boot rubber fits so snug that I was reluctant to use a hose clamp around the exterior diameter.

Photo 5. Slip the cut edge of the boot over the fan housing

Slip the fan and coupling clamp back on to the heater box taking care if you have the old cardboard style as found on the 4-cylinder Ponton models. Tighten the clamp until snug. Then attach a strapping clamp (the original one is superior to today's modern stainless hose clamps) around the duct and new boot, reconnect the wires, and away you go. The rubber may not be as thick as the original, but you'll like the price, and the shiny new effect it has on your Mercedes-Benz and your wallet.

Photo 6. The finished product