How to replace heater valve O-rings? - PeachParts Mercedes-Benz Forum

240 Ed · #1 01-02-2003, 09:07 PM

I now have access to the inside of the dash because I foolishly thought I would replace a light bulb in the heater lever unit...

Oiy...

The reason my levers are all broken up, is that the valves are frozen.

Do I need to remove this valve from the engine compartment to replace the O-rings, or can I just pull the guts out from inside the dash...?

ctaylor738 · #2 01-02-2003, 10:03 PM

You need to take the valve assembly out. On each rotating valve, there is a circlip that holds the rotating part. You remove the circlip and then work the rotating part out of the body. I would throw it in some carb cleaner for a day or so.

BE CAREFUL to not exert too much force on the little square piece with the screw hole in it. They break off easily - BTDT.

240 Ed · #3 01-03-2003, 09:37 AM

Thanks for the comeback Chuck, and another congrats on your car.
And thanks for the tip on the fragility of the thing. I was going to have at it with a plier, but will go slow now...

Oh, and what does BTDT mean?

ctaylor738 · #4 01-03-2003, 11:19 AM

BTDT = Been there, done that!

Also, after I broke mine, I got another unit, so I have some parts if you need them - including one good valve!

240 Ed · #5 01-04-2003, 05:44 AM

Thanks for the comeback, Chuck.

This weekend I am going to tackle pulling the rear end out of a V8 in a muddy junkyard (Yuk oh) and if I have time and energy will look at the heater levers, etc. This car is gorgeous too, was junked for a minor engine fire. Even has all its wheel covers! And good wood!

Tomguy · #6 01-10-2003, 12:00 AM

I got my heater levers today: Beautiful Febi set for $75 with shipping!
I put the unit back in today. So far I've spent 2 hours total on the heater levers (6-8 my you-know-what).

Now... my heater valves aren't frozen, but rather hard to turn. I don't see how to take them out. (I didnt unscrew the slotted screws on them even... I don't want to touch them w/o asking).
How do you take them out? Unscrew that, then the circlip holds the whole valve assembly in there? I didn't see any clip

240 Ed · #7 01-10-2003, 09:13 AM

Tom,
That is what I see that needs to be done...
I can just see the circlip behind the "lever".

The problem I have, is trying to get the slotted screw to turn.

You have to have just the right length driver to properly seat into the screw head, then have a small, insanely strong hands to push and turn the thing without stripping out the slot...OIY VAY!

Tomguy · #8 01-10-2003, 08:42 PM

Ed: You too must be hesitating on this front, I am thinking of taking my 18-volt drill and putting the slotted bit in it and holding it in there TIGHT while SLOWLY trying to take it out. It will either remove it or strip the screw.
I can't see the circlip behind it but I'll take your words for it. But another thing: The cables for the air flow control (that go on to the heater levers too, not the valve ones) are stiff on the passenger side, and frozen on the driver's side. How do I lubricate the flap (that I can feel on the pass side, but not the driver's side)?

psfred · #9 01-10-2003, 09:19 PM

Tom:

Most likely the cables are at fault, not the flaps, since they are just wire in a hole in the plastic case. Unless, of course, you have a family of mice living in there that built a nice nest in the heater box...... Don't laugh, I've seen it before, even on new cars.

Unclip the lever for the flap to check. You may need to remove the console cover -- one screw under the carpet on the passenger side, just hooks under the shift column (or somewhere, I don't remember) on the driver's side.

Heater lever lamps are accessable from the speaker gille, in case you didn't find them -- under the little black cap on top of the levers.

Peter

Tomguy · #10 01-10-2003, 11:33 PM

Quote:

Originally posted by psfred
Tom:

Most likely the cables are at fault, not the flaps, since they are just wire in a hole in the plastic case. Unless, of course, you have a family of mice living in there that built a nice nest in the heater box...... Don't laugh, I've seen it before, even on new cars.

Peter

Ok, so... how would I clean out the mice nest? Don't laugh, it WAS sitting for 4 years doing nothing. I tried to get most of the stuff out by pulling it out and then later, with the ShopVac, but I suppose that wasn't enough.
The passenger side one moves, just stiff. Suppose it'd work better if I greased the cable? If so... how DO you grease them?

psfred · #11 01-11-2003, 11:30 AM

Penetrating oil is probably the best treatment on the cables, especially if they are bare, not covered with plastic. If the housing is plastic covered, you can only put some on the ends and work the cable back and forth.

Other than fishing with a wire and a vac, the only way to clean out the vents is to remove the heater box, a serious chore. I'd unhook the cables at the flap (under the console cover) and verify that they are dragging badly before I got excited -- the usual cause of stiff heater levers is the valves, not the flaps.

Mine are out of adjustment -- can't get the driver's side all the way to hot, can't tell if it is the valve or the flap at the moment, and it's very cold and windy outside today, will probably wait for warmer weather to work on them!

Peter

Tomguy · #12 01-12-2003, 12:13 AM

Peter: The heater valves are tough to move, but the flap control for the driver's side is completely frozen.
I can't really get my oil can at a good angle to get into the cables either >_<
I've been working on the exhaust for now. I FINALLY got the -ass. side exhaust headers off, and the pipes off them, but I can NOT get the other pipe (the lower section they cracked off of) out of the pipe that goes into the muffler. but I will (probably Monday, dunno if I'll do any work on it tomorrow)

psfred · #13 01-12-2003, 02:09 PM

Tom:

The exhaust header has probably been dented in by the clamp. If you can find an exhaust pipe expander (cute little thing that has steel sections that expand outwards when you tighten a bolt in the center), stick it in there and re-expand the pipe.

This may and may not get the pipe free enough to remove -- I usually just get a hacksaw blade holder out (the little on that leaves one end of the blade free) and slot the pipe so I can collapse it and get it out without ripping the muffler pipe up.

I hate exhaust work (which is why I still have a split header on the 280 SE 4.5). How bad is getting the left manifold off?

The only way the flap can get completely stuck is if there is a mouse nest in there -- sounds like more fishing, or worse, heater box removal. The valves will be easier with the heater core out......

Peter

Tomguy · #14 01-12-2003, 05:18 PM

Peter: Well, then it'll have to remain stuck (in the heater on) position. I am NOT taking the whole thing apart. Too much of a P.I.T.A..
The exhaust headers on the pass (rt?) side weren't too bad. You WILL need a 12mm combo wrench though. I needed a 13mm one to undo the tranny dipstick and move it a little out of the way to fit the wrench in and take the headers out.
However, I do NOT know how hard it will be if your pipes below arent cracked. Mine were, so I was able to pull them up and take the upper one apart, then remove the lower one with the pipe still on and cut the bolts. It will be a PITA too unless you let it soak in something (I used "Break-free CLP").

psfred · #15 01-12-2003, 06:19 PM

Tom:

A complete exhaust system is in the works anyway, I may just wait. I expect to have to cut the bolts unless I can break the heads off (the usual result on exhaust manifolds). I've heard the pipes tend to rust in place, too.

My left header is flattened about half way (college boy was driving the car before I got is, nuff said?), so I have to replace it at least, and I'm fully confident that both mufflers are shot.... another $600 plus shipping......

I finked out on the levers today, too cold.

Full heat is much better than none!

Peter