Climate control system crisis

[michaeld]

You did it! Nice job. I now appoint you the "Servo By-Pass King of North America."

Thank you for this great honor.  I promise to use my tremendous powers as servo-king for the good of all the people, and not merely for self-aggrandizing gain.  May all of you Servo-serfs thrive under my wise and beneficent rule...

I really appreciate your help on this issue, Jim.  I would have had to purchase that $50 kit just to have the instructions without your tutelage.  If I have the title of "Servo By-Pass King of North America," then you are surely "Yoda, the Jedi Servo Master."

Actually, in terms of kinking, I am more concerned with the top of that "D" hose than the bottom.  I haven't hose-clamped anything yet, as I figured I wanted to do more tweaking.  The car aint going anywhere for a while anyways (I'm awaiting a couple of water pump-related hoses).

I didn't bother to trace those vacuum lines, just assumed I'd need to plug them.  I'm one of those "Don't-think-just-stick-your-finger-in-that-leaking-dike" sort of guys, I guess.

In your earlier post you mentioned the bracket coming out.  I first tried to take out the bracket (it was easier than getting to those two screws holding the servo TO the bracket), and got two bolts out before being stymied by what seemed to be a rivet.  You called it a "tab," and I guess I should have played with it a little more.  I've left it for now because A) I might be replacing the servo soon anyway and B) I might want it to attach something else to. 

I noticed in your pics that some aspects of your car are different than mine.  For example, your model clearly has the washer fluid reservoir next to the servo; mine is between the expansion tank and the battery.  I thought that was interesting.

Hermosa Beach, huh?  Never been there.  I had to look it up on a map.  Some California native, I guess!  I've got a trip of my own scheduled for Jan 10th - to Denver.  After all their problems, I am not looking forward to that trip.  I don't even like to sleep in hotels.  But being a snowbound refugee in an airport?  No thanks!  Maybe if I start chanting, "Snow, snow, go away; mess with someone else's day..."?

Tomi,
I have to agree with you.  In a cold climate, functioning heaters and defrosters are a bit more than the trivial afterthought they tend to be in Southern California.  In Palm Springs, one can pretty much forget one even HAS a heater.

I'm not planning to rush into replacing my servo right awya, simply because I don't have to.  I will consider the options and shop around for the best deal.  I DON'T want to pay a ton of money for something I KNOW will break after a couple of years, the way these units have been wont to do, I know that much.  One question I've got is whether one can modify a later model (and hopefully mechanically more sound) system to fit our cars.

[michaeld]

JJCCP,
Hey, I've got to post ONE more time on this servo bypass thing because I'm having two conceptual difficulties that I'd like to clear up.

The first has to do with the routing of the hoses.  I was fairly sure - when I initially routed the hoses - that I had things right.  And then you looked at my pic and said, "Not quite."  I was a bit puzzled, until I went over your post again.  Now I understand why I was confused.  You are identifying as the heater core inlet what I had identified as the heater core outlet.

Using our same terms, you told me that Hose "D" (labeled on the MBz diagram as the "heater water feed" from the engine, and which you said was "where the coolant first comes out of the engine...") connects to Hose "A."  You describe Hose "A" as going "into the heater core inlet... which is the one that goes over to the driver's side of the engine bay..."

Here's the MBz diagram, that I marked with crayon and ink to reflect my understanding.



Hose "A" is my problem.  As I look at the MBz diagram, it still seems to me that Hose "A" - the hose going into the driver's side of the firewall - would be the heater core OUTLET, not the inlet.

Mind you, other than this diagram, I have no idea WHICH heater hose is which.  But as I look at the diagram, and follow the arrows notating water flow, I see an arrow directly below the heat exchanger (the line below the "c" points right at it at the top of the diagram) that seems to indicate the hose on the driver's side to be the outlet hose; i.e. water is flowing FROM it.  And I see another arrow on the hose going into the passenger side of the heat exchanger that is pointing INTO the exchanger (i.e. the inlet).  THAT is why I initially had the hoses connected the way I did.

So as I look at how I have the hoses routed now (as per my last pic), it seems like I've got the outlet from the engine feeding into the outlet from the heat exchanger.  It seems like it would be reversing the water flow through the heater from what the diagram shows.

Now, the fact that you've been driving the car with the hoses so positioned is a strong indicator that you did things right, but the conceptual issue is driving me more nuts than I already am!

You've been very patient with me so far, but could you explain how I'm reading the diagram incorrectly?  I've looked at it several times, and I just don't get it.

Okay, that's my first conceptual issue.

The second issue is something you actually didn't do, but Papalangi did (so perhaps he's the better one to answer this): install a valve in the system.

Many people who bypass the servo are installing some kind of a ball valve in order to selectively cut off water flow so that the heater will not continuously run.  That way they can turn the heater off in the hot months and on in the cold months.

Well, as I look at the diagram - or the actual hoses on the car - what I see is a single water circuit.  The water basically runs in a big rectangle.  Well, if I cut off the water at any point, don't I interrupt the circuit?  Wouldn't installing a ball valve totally screw up the water flow through the engine, even if I installed it on the inlet side of the heater?

Again, the fact that people are DOING it (installing valves) tells me that I must be missing something.  I would like to have the option of shutting the heater off selectively for the time being (remember, I DO live in the southern CA desert).  But I frankly just don't know where to put the dang thing!

Mike

[Papalangi]

Good morning Mike

I haven't seen a diagram for the V8 water flow but I think that the feed comes from the front of the engine and returns to the rear, opposite of the DOHC six M110 in jjccp's diagram.  That might be part of your confusion.

The heater core cares not about flow direction other than if there are deposits and you flow it backwards from the last 30 years or so, they could come loose but I wouldn't worry about.

Ben (the PO of my car) took d and e out of the circuit and removed the short curved hose between them.  He coupled the inlet to e and the outlet of d together.

On the firewall side of d, instead of a coupling, he installed a ball valve.  This controls the flow of coolant through the heater core and thus the temperature in the car.  The unwired tools kit uses a vacuum controlled valve in place of my ball valve to do the same thing and the kit from www.mercedessource.com uses a cable controlled valve.

Bear in mind that the servo does in fact close fully and stop the flow of coolant through the core and that the aux water pump is both thermostatically controlled and controlled by the climate control panel.

If you never needed heat, you could just connect a and b directly together without a problem.  In fact that's what I thought you had done.

Michael

[jjccp]

Did I screw that up?

Really sorry Mike. Like I said before, I should have taken better pictures. Thank you Mr. Papalangi and I agree that the heater core doesn't really care which way the water flows. Anyway, it worked fine for me.

Regarding the valve, I didn't need it. When I did the by-pass, the only button that worked was the defrost button. So I had full-blast defrost or nothing when I hit the off button. I didn't notice any heat flowing on it's own while the off button was depressed, but it was November in Michigan. Will there be some heat coming into the car on a hot day in California, I can't tell you. You can dirve it first and find out.

[michaeld]

Good evening, Papalangi!

Hadn't heard your "voice" for several days. 

I initially HAD hoses "A" and "B" connected together, but Jim told me I had it "back asswards."  So I re-routed it according to his suggestion.  But while I frankly trust Jim's instructions over my instincts in this matter, I've been pondering over it ever since.  It all seems to boil down to which side of the heat exchanger/core is the inlet side, and which is the outlet side. 

On MY V8, I can tell you that both the "outlet from" and the "inlet to" hoses on the engine are on the back of the engine near the firewall.   

I didn't THINK having the heater flow backwards would be an issue - although I didn't think about the reverse flow creating a "flush" condition either.  But I'm one of those Freudian-anal-stage-types that likes to have all the ducks marching in precise cadence.  Sometimes it is SO VERY hard to get all the ducks marching right...  I will probably go ahead and try to flush the heater while I've got the hoses off.  I've never actually flushed just a heater before.  Instead of one of the copper pipe lengths, maybe installing a 3-way on the inlet side? (but, darn, there I go again, needing to know which side is my inlet side...).

I'm a little vague on your ball valve instructions, partly because I'm not sure if you're referring to my initial A-D hose descriptions from my first picture, or to the MBz diagram.  If the latter, there are actually 2 sets of hoses between my heating pump ('e' on the MBz diagram) and my servo (regulating valve "d" on the MBz diagram).

It turns out that simply purchasing the kit (from mercedessource) isn't as bad of a deal as I thought, because to purchase an automotive valve all by itself will run nearly $30 before shipping.  I'd kind of like to try a bypass before spending an absolute minimum of $300 to have my servo rebuilt (if it is still even rebuildable).  But I'd sure want to do it right.

Now another question comes to mind as I read your post: is the "auxiliary water pump" identical to the "heating water pump," or are these two separate units?  If the latter, is the auxiliary pump located underneath my battery box, as I used to believe it was?

I'm not really all that interested in having heat right now, other than the fact that I've always been under the impression that having the heater on can help cool an overheating car. 

It's kinda funny that you send me that mercedessource link; I had lost that source link, and couldn't find it, and spent a good hour plus looking for it before finally finding it again.  I wanted to see what the kit looked like.  Of course, If I hadn't searched high and low for it, you wouldn't have posted it right in front of my face a couple of days later!
Mike

Oh, JJCCP posted between when I read Papalangi and when I tried to post.  So I've got to say "hey" to Jim.  I think it all depends on whether the diagram we're looking at is same-same as the 4.5L.

Now, frankly, that defrost is the only thing that would be pretty cool to have.

So, in any event, I'm still a little confused about "hitchin' up my plumbin'."  What I CAN say is that I'm still very grateful to you because you gave me the initial info and pics to get started, and you provided me with a basic idea of what I was working toward.  I'd probably have been hunched over my fender scratching my head like a chimpanzee for another couple of weeks without your input!

In any event, in order to hook everything up in that anal-stage-like manner, I'd like to know for certain which is the inlet and outlet on the engine, and which is the inlet and outlet on the heater.

[Papalangi]

It's good to be back, Comcast took nearly two weeks to come back to full speed after the storm.

I was referring to the lettered components of jjccp's MBZ diagram rather than your lettered hoses. And yes the heating pump and aux pump are the same thing.

I see that the mercedessource kit is on sale right now.  It might be a good idea as he provides very well written and photographed instructions.  I have the seat repair book and found it to helpful.

He does talk about the need to check the aux pump out before you install the kit but the pump does not run above 60F or 70F ambient temp. I don't think you will have a problem with getting cold while sitting at idle in sunny California.  In fact my pump is in a box in the garage and I haven't missed it yet.

The only pump under my battery box is the windshield washer pump.  The aux water pump is attached to the servo bracket with a hose clamp.

As a funny aside, the spell check insists on changing "jjccp's" to "skycap's".

Michael

[michaeld]

Papalangi,
It's like WAY past my bedtime, but I saw your post...

I have to agree about the kit: at first I thought, "60$ for some hose clamps and a sheet of paper?"  Now I'm more like, "Well, half of it's for that valve, and I really kinda WOULD like to see that sheet of paper!"

Thanks for clearing up your "A-B-Cs" from mine.  I'll have to go back and re-read your post with that newfound knowledge.

Thanks also for the clearing-up re: the "aux water pump."  I came across some oblique references, w/o any description of location.  And then I saw that pump below the battery box...  And THEN I see a diagram featuring something called a "Heating Water Pump."  That was just two too many pumps!

As for "JJCCP" being changed to "skycap," maybe it's because "skycaps" are slang for alcoholic drinks served on an aircraft.  And pilots are known to drink some of those aforementioned "skycaps" during flights.  And then they try to type, and instead of the word they're typing, they instead type .... "JJCCP."

Just a possibility.  Part of deductive logic, after all, is starting from an event and then reasoning back to possible causes...

Hang on a second.  Let me just finish my bourbon and I'll jjccp

[michaeld]

Hi, guys,
Long time no posts (to this thread).

Have an update.  I've had a number of problems, mainly waiting FOREVER for various hoses, gauges, and etc. 

There are two hoses behind the water pump; one is clearly a heater hose, and the other is some kind of system bypass.  The latter (it turns out) is a 42mm hose.  Using a 1 3/4" turns out to be a BAD idea.

In any event, after a couple of abortive attempts, I appear to have the servo bypassed, and the water pump hoses running without leaks. 

Haven't determined whether I'm actually running hot or not.  But thus far, all seems good.

Within the next couple weeks, I will be picking up a 1973 Pontiac Grand Ville with a 455 c.i. engine and true dual exhaust (no catalytic converter, and BTW, no smog pump).  This car actually has slightly better engine specs (torque and horsepower) than a U.S. 6.9.  It will be fun to compare the two cars to each other.

The 6.9 (at least according to some writers) is a near 150 mph car in top form.  The Pontiac is a sub-130 mph car.  I aint about to compare top speeds on either.  What I am interested in is the low-end performance.  I expect the Pontiac to have gobs of that.  It will be fun driving the Pontiac, and then my 450SEL.  I'll write a post on that cf. at some point.

I'll also write a post on whether or not I run hot on the new gauge.

One interesting possibility a friend suggested.  I've got a vacuum leak relating to either a bad brake booster or a bad seal to the master cylinder.  I haven't dealt with it because when I've thought about the  450SEL, it's been about the cooling system.  Well, a friend pointed out that a vac leak would affect the air/fuel ratio, and that whether one runs too lean or too rich, it can cause overheating symptoms.

If I am running hot, I will try to deal with that booster vac leak before taking the car to a mechanic.