Haha ok bro I'll be sure to avoid unhooking that air cond hose. When you say drain some coolant you are talking about the 50/50 right, not freon. Just making sure.

Oh which reminds me, what kind of freon does the '80 300TD take?

Tony

Tony:

If you can find R12, that is what was there originally. 134a works fine, just charge only to 85% of capacity and add the minimum amount of ester oil necessary to convert unless you completely flush the system, in which case add the MB recommended amount.

That does look sorta tight in there, but better than my 300D -- had to take off the air filter to turbo hose to get to the thermostat, then replace it "blind" as I can't see through my hands!

Coolant is glycol antifreeze, the stuff in the AC is refrigerant!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

That pic isn't my car, mine is tighter than that! Very tight area around the thermostat.

Ester oil?

Tony:

Synthetic poly-ester type oil used to convert R12 systems to R134a -- dissolves in both the old oil and in the R134a. The oil in an AC system is dissolved in the gas (or liquid) freon. The old petroleum base oils aren't soluble in R134a and cause problems.

A moot point if you AC still works!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

I disagree with Bill--the middle vents blow ice cold air when the AC is on and working properly. I've had three 123 diesels, and it's been the case with all of them.

The heater problem is probably related to the automatic climate control servo--assuming it's the old Chrysler style (if your push buttons are vertical, it's the Chrysler syster). They are notorious for going bad.

Where is the servo, how will I know if its bad, and how much is it to replace!

Anthony,

Assuming you have the old style climate control (with the vertical arrangement of the push buttons on your dash), you'll find the servo on the passenger side of the engine compartment, not far behind the headlight, actually. It's a black thing with a number of small heater hoses and vacuum connections going into and out of it. My recollection is that they run in the $300-400 range. George Murphy, of the Mercedes-Benz Club, sells a version of it with an aluminum pot, which solves the chronic problem of the original equipment units--leakage because of the plastic housing. I think George's model is more expensive, though. Good luck.

Oh, by the way--I have a wagon too, and I have done some work on that rear suspension. The air cells are crucial to a decent ride--struts are bad if they're leaking, and should be replaced in pairs, if replacement is necessary.

Joe

I changed out the t-stat today with an aftermarket one from O'Reily. (Peice of CRAP) Still no heat at all, NOTHING at all. You get air blowing out based on the temperature outside, if its cold, air is cold, if its hot, air is warm.

I can't afford to replace the servo so if there is anything else I can try to do please tell me.

Thanks

Greetings Anthony,

I've been through your problem already on the same year and model Benz. From the sound of it though you don't have any manuals at all to help you locate parts or their function so let's do it this way. First off, do you get heat to the windshield when you push the defrost button and the engine is at operating temps? If you don't then the next thing is to troubleshoot the problem. Send me your email address and I'll send you the pages out of the manual that describe each sensor and how to troubleshoot them as well as your adjust your temp wheel rheostat. This one was the culprit on my system.
You'll probably find with time that your usual sources for car parts like O'reilly , NAPA etc. should be your last source for parts for your Benz. Try the parts shop right here on this sight such as Fastlane. Most parts you'll require are of better quality and from more reliable manufacturers when they are coming from Germany.


Charles

__________________
"Tell me and I will listen, Teach me and I will learn, Show me and I will accomplish, Involve me and I will succeed."
'84 300SD 256,000 Gold on Brown (Mileage Award)
'86 300E 246,000 Blue on Tan

http://cgi.ebay.com/ebaymotors/aw-cgi/eBayISAPI.dll?ViewItem&item=598785658

Thanks for all the help guys but I cant afford to fix this car. In the future guys, in the future.

Sigh.

Tony

NOOOOOOOOOOOOOOO DONT DO IT!!!!!!!!!!!!!!!!!!!

these cars ARE NOT hardto fix. They take a little bit of patience but with everyone helping you here youll have it fixed up in no time!!!!! You can get alot of these parts used from a dismanlter for european cars. Stick with it, I thought the same thing with my 300SD but had it fixed up for HALF the cost of what i thought it would cost. MIne had more problems then urs too! give it a little moe time....
Ryan

__________________
83 300SD.......sold
96 integra SE....sold
99 a4 quattro....sold
2001 IS300.......sold
2002 330i.........current.
2004 highlander limited....current.

Greetings Ryan,

Sounds like you have thrown in the towel before the fight. There are some folks out there that are enticed by that three pointed star car but don't relize the time that is involved to just keep them looking good and running good ten, fifteen, or in my case over twenty years down the road. Most American cars can't compete in reliability or simplicity of maintenance as these older Benz's can. Of course most Americans just want to get in their car and go and stop for fuel whenever the needle redlines or zero's out. As far as maintenance, Americans are probably the worst on maintaining their rides, they rely on shops to do most of their repairs, and a lot of them are missed when something else is getting attention at that time. Almost all of the problems you have mentioned about you car are easy fixes and in most cases the most expensive part of it, will be your time to troubleshoot. From everything you have said is wrong, would most likely take you a weekend to troubleshoot and repair.
It was nice to have you on the forum at least for a short while.

Charles

__________________
"Tell me and I will listen, Teach me and I will learn, Show me and I will accomplish, Involve me and I will succeed."
'84 300SD 256,000 Gold on Brown (Mileage Award)
'86 300E 246,000 Blue on Tan

Wish I could keep it, but I really don't have the money to fix it up. Even if it costs half what Im estimating it will cost, thats still too much.

Beleive me, I'll be rejoining the MB club again soon, hopefully with an early 80s wagon again too, but when I do I'll have the cash to spend fixing it up.

Charles: I spent an entire week working on JUST replacing the thermostat and trying to stop the resulting coolant leaks, and I ended up with a new problem with the old problem having gone nowhere. (Car now leaks coolant in addition to having no heater)

I love MB automobiles, always have, but I am not mechanically inclined (Hell, I fix computers for a living) and just doing simple stuff (simple for most of you) is a nightmare for me.

When I bought the car I knew i had to fix the suspension and I was prepared to do it, even if it cost some money and required some time to work on it. I forgot to check if the heater worked when I bought the car because I KNOW the guy I bought the car from and he told me the heater worked fine so I didn't bother to check it. (I know now I should have anyway to be sure)

I don't have time to mess around with a non-workable car, even if it IS fixable and the DIY fixes were within my price range, Im not good enough with cars to do it myself, and taking it to a MB tech would cost more than I can afford.

Sigh.

Greetings Anthony,

Since you've decided to sell this car, you might as well tinker with it while you still have it. The coolant leak you have from the thermostat housing is most likely caused by not installing the rubber seal that goes on top of the thermostat before installing the top housing. If you did install the rubber seal, then the three screws holding the top on are most likely not snugged up. The only other leak you could be having in that area would be coming from a hose clamp not being tight.
The heating problem, just from what I would guess could be the result of a misadjusted temp wheel rehostat. To do this fix you need an extremely thin piece of metal, I used a piece of roof flashing aluminum, worked great. It needs to be about 5 inches long and 1 1/2 wide cut little teeth with a tin snips in one end of it. When this is done you have your special tool. Start up the car and get it to operating temps, preferable to do this in the morning so you'll feel the heater temp difference when you adjust it. Looking at your temp wheel set the temp to full heat. Next slide the thin metal tool, teeth forward between the wheel and the dash housing on the right side of the wheel. Push in till you feel the teeth grab the gear that is on the shaft, then slowly move your temp wheel to half the heat setting while keeping tension on your home made tool. Remove your tool and move the temp wheel to high heat again and see if heat doesn't once again start to flow from the vents. Mine got out of adjustment from Summer to winter so I assume it's possible yours has too. No money involved in this fix. The water valve assembly in most cases, by looking at mine seems rugid enough unless just water was used in the cooling system to hold up for years of use. I wouldn't suspect it as the first cause of a heating problem.

Give these fixes a try while you're waiting, you may be surprised at what you will accomplish.
There might even be folks on this site around your area that require your computer skills as a trade off for their mechanical skills.

Charles

__________________
"Tell me and I will listen, Teach me and I will learn, Show me and I will accomplish, Involve me and I will succeed."
'84 300SD 256,000 Gold on Brown (Mileage Award)
'86 300E 246,000 Blue on Tan