74 240D heat and parking brake

My 1974 240D is hitting its first winter with me, and as I'm driving around, when I turn on the heat, it's damn cold! But if I turn off the fan, hot air (but very little of it) comes out of the proper vents. Is this normal, or is there something very wrong when you kick up the fan speed and the air gets colder?

Also, my parking brake keeps getting stuck in the "engaged" position, even if I release the pedal. I've tried loosening the pad tightness (via the star wheel at each rear wheel) but the brakes get stuck again when I engage the e-brake pedal. Is there a good fix for this?

Reply to
Sunilito
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If the engine temperature is at 80 degrees C (specification) then the heater should work. If it doesn't you need to check the warmth of the heater hoses at the firewall where they enter the cabin and determine where they're hot and why they're not.

Keep in mind that diesels don't heat up as quickly as gas engines but there should be decent heat after say, two miles of local driving.

Reply to
T.G. Lambach

Oh, I'm talking about when the car has reached full operating temperature (temp gauge says 175 degrees or greater). Whenever I turn the fan on, it blows cold, but if I leave it off, hot air trickles out of the side vents.

What would the heater hoses look like? If they've disintegrates, or simply aren't there, what can I use to replace them?

Reply to
Sunilito

They're there all right or there would be no coolant in the engine. Look for two probably black rubber hoses the diameter of garden hose running from the engine to the firewall. One, at least should be 175 degrees F.

I suspect your car's heater control valve is stuck shut - no heat. Take it to a repair shop, should be a simple job to replace it.

Reply to
T.G. Lambach

Heater hoses area about 5/8" inside diameter, external diameter is about 7/8". There are two of them running from the engine through the firewall into the heater core located inside the dashboard area. One brings hot coolant in, the other returns it, completing the loop.

If they disintegrated or weren't there, you would have coolant spewing everywhere and an overheating engine. If you have no heat coming out of any of the outlets (dash, floor, defroster) with the blower on, yet have a little heat with the blower off, it sounds like you may have only a little coolant flowing in the loop. Could be the control valve or a blockage.

Reply to
Chet Hayes

Ok! Muchas gracias for all your help. However, a previous post said to take it to a repair shop to have the heater control valve replaced. Can I do it myself, or is it too complex? Also, are the heater hoses easily recognizable by material or color?

One more thing - is there any danger of disconnecting the heater hoses with the car NOT RUNNING (i.e., is the system pressurized and do I have to relieve the pressure somehow)? I want to check for blockages before I take it in for repairs.

Thanks again.

Reply to
Sunilito

If you disconnect a heater hose while the car is cool, the only thing you'll get is some small amount of coolant from gravity flow and how much depends on where the line is that you open. It's only under real pressure when it's hot. Before unfastening any clamp, remove the coolant cap which will remove any small amount of remaining pressure in the system. If you want to minimize any coolant flow, then you could drain the radiator.

The only hoses running thru the firewall that would look anything like heater hoses are the air conditioning lines, which go to the air conditioning compressor, not the engine. The air conditioning lines use fittings, while heater hoses push on over a barb type fitting and then a stainless steel band type screw clamp goes over them.

I don't know where the heater control valve is located in the 240D. How accessible it is and how skilled you are would determine if you can replace it yourself. If you find it and can get at it and want to verify that is the problem, you can try bypassing it with a short length of pipe, which would give you full heat.

Reply to
Chet Hayes

Besides checking the heater control valve postiion is not partially open. Also check the cable leading from the heater control on the dash to the heater valve.You may find the valve works ok if you can operate it manually. If so, then look for the control cable to be working properly.

One more thing may be that you have a blocked heater core (rust, etc). If you can (weather permitting)you can run water through one of the heater hose and see if it is returned through the other hose.

I had a car with a good heater valve and cable that was not attached properly that acted similartly until it was anchored properly.

BTW: Although I am not familiar with your particular model car, onmost cars the hoses you are looking for will usually run to the outer (engine side) of the firewall (the heater core is on the cabin inside). The control valve is usually attached to the heater core (cabinside) although I have seem some cars with the valve on the firewall (engineside).

The heater core itself is generally in the center of the firewall although on some cars you may find the heater on the passenger side. Sometimes its easier to locate from the inside when looking for the heater core which is usually placed near the blower fan.

Hope this helps.

Reply to
MC

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