Temp Gauge Wire Replacement

[rmmchl]

does anyone the correct steps------------does it unscrew from the back of the guage?-does the cluster have to be removed keeping the wire connected to the cluster? ---what is the correct procedure-can we buy a new wire/capillary tube----or does palo alto or someone have to take the guage and re-do it?

[glennard]

It is a tube filled with a hydrocarbon liquid.  Do not twist, bend, fold, or mutilate.  Otherwise, you have bought the store.  The bulb end in the engine is held in by a keeper.  The needle end(bourbon tube) on the dash is held in by a boss.  The tubing between is encased in a wire mesh shield.  Be good.

[rmmchl]

i dont know what a keeper or boss is------what does it take to fix it---I'm an optimist-yes, we have a problem-now how do I fix it

[DaveB]

Yes you can buy a new one but it will be expensive. They can apparently be repaired but you might be better off buying a good used one or a complete used center cluster (230-280SL, 220SE, 250SE coupe). The "keeper" is threaded and should undo easily (bearing in mind the advice about not twisting the capillary tube).I'm not sure what the other end looks like but I think you'll need to remove the entire cluster from the dash before extracting the temp guage.

[bpossel]

One screw holds it to the rear of the center cluster.
Use lots of penetrating oil and soak the threads where it screws into the engine.  It does come out, but as stated, you need to be very careful.
Bob

[James Stern]

 

Hi Bob,

I haven't seen you post in some time.  Is all OK?

Jim S

[bpossel]

Hi Jim,

All is ok...  will post more on the resto soon.  Has been very challenging getting all to run good again...  These cars can be little boogers :twisted:  when they dont run right....  Bob  

quote:Originally posted by James Stern

 

Hi Bob,

I haven't seen you post in some time.  Is all OK?

Jim S

[James Stern]

Bob,

That's what I was afraid of.  God help the rest of us if you have had a problem.  I gather it was the engine timing issue?  Either way, all of us are wishing you the best (and hopefully calm waters) for the rest of your journey.

Jim

[Cees Klumper]

rmmchl - I had the problem with the broken capillary tube last year and the way I corrected it was by replacing the tube + gauge as one unit; don' t think they are supposed to be separated. It was expensive but effective. The replacement procedure was straighforward, I believe I took out the center cluster, undid the connection at the engine block, pulled the tube out through the firewall, took out the old gauge, put in the new gauge into the cluster and fed the new tube through the firewall, screwed the new tube into the engine block and, presto.

[Richard Madison]

I wrote what I thought was a helpful article for the Tech Manual about the temperature gauge but it does not seem to have been noticed.

http://www.sl113.org/wiki/pmwiki.php?n=Electrical.Temperature

Richard M, NYC

[J. Huber]

OK. New potentially horrible problem here. I am afraid the Idiot has struck again....

I have recently been cleaning up my engine bay. One of the things I did was replace the TTS rubber cap and also removed the spark plug bracket and wires for refinishing. So there is a good chance I bumped and tweaked the capillary tube where it enters the block. I was pretty careful but it clearly may have got jostled.

fast forward to today. Break in the weather, decided to give the car exercise. Ran fine -- but as one of my goals was to get the car to operating temperature -- I was very surprised to see no movement of the temp needle. I know I was out long enough for needle to move. Have I really F---ed things up this time?

I never smelled any odors. The wire at the block is exposed about an inch and a half-- and it looks a bit frayed. I did notice that housing is hotter than blazes when running -- suppose thats normal but why else would needle be asleep?

[Benz Dr.]

Yeah, you probably broke it. The capillary tube is filled with ether and you can smell it right after it breaks. The smell will go away quickly so don't count on that as any help to source to problem.
Putting the ether back into the gage is hard to do. I think they use a specified amount and use some sort of vacuum system. If you get too much fluid in the system the gage will read high and too little it reads low. It's not for the faith of heart or back yard DIY types to even think about trying. Aside from the fact you could hurt yourself, the small rebuild cost relative to over heating a perfectly good engine is worth it.

[merrill]

PA speedo can repair yours and calibrate it.

I think the repair runs about 180 bucks....

http://www.paspeedo.com/

[J. Huber]

Thanks Dan and Matt. I am sure its a goner. The wire at the block looks very thin and frayed, and as someday told me today, it may have been on borrowed time even without me messing around the area. So, my next decision is: do I send it to Palo Alto or do I buy a new temp gauge assembly and try and put it together myself. I realize the latter is a 300 dollar proposition.

I already called PAS and he said I'd have to send it in before he can give me a quote on the repair. Fair enough -- I know they do good work --but I am sure Matt is correct it will be close to 200. Does a "repair" mean they mend the existing tube or would they possibly replace it...I'd hate to save a 100 dollars and have a bandaid on a 45 year old capillary wire...

Finally -- what about driving the car? Is the gauge critical to engine function? I realize long-term it is critical to knowing the temp but does it control any of the other devices as well? Thanks Guys.

[glenn]

I have one in the garage(?where?) for sale.   Filled thermal system-bulb in the block, capillary tube, and bourbon tube gage on dash.

[J. Huber]

Thanks Glenn. But I decided to let Palo Alto Speedo. have a shot at it. I was able to successfully pull the center cluster today and have shipped it off. The capillary tube at the block literally deteriorated and separated in my hand. So that was the problem for sure... I have a little time to shore up things around the dash -- and may pull my speedometer out since I am so close now. It works fine but the odometer does not. I thought about sending that to PAS as well but I like my kids and house alot... 

I have seen that the odometer can be tinkered with -- so that may be next for me. I am wikibound.

[J. Huber]

Update on my recent temp gauge issue. (The capillary tube had completely disintegrated and broke in two.) I ended up sending the center cluster and my speedometer to Palo Alto. The cost for just the temp gauge repair was about 165 -- same price for the speedometer to be serviced and trip meter repaired. Quick turnaround which was nice. They are back home safely and went in today. Speedo went in easily. The temp gauge, however, gave me some trouble. First off, I enlisted my wife to hold the cluster and carefully feed the capillary line as I worked it through the spaghetti from underneath. That part went smoothly. But when I attached brackets, for some reason, the nut on the left had no room to spin on the post. I ended up filling the bracket down to where I could at least get the nut started... that was very strange. Then the tach went in fine.

And what else: a new issue... so I tested the dash lights (new bulbs) and they all came on. However... now my rheostat is not working. The lights are bright which I take it is lucky -- but they do not dim. Once I got done swearing -- I removed tach, then checked wiring as best I could, and put it back in. After that nut job (no not me) I decided not to remove the cluster again.... I suppose I screwed up the rheo along the way? If the lights are on and bright, not much I can do is there? I can live with it but its frustrating as heck to take 2 steps forward and give one of them back...

[J. Huber]

Hello again. So I have a question for Jeffc280 or anyone else who dares to solve electrical riddles...

I am all buttoned up on the dash -- but have a couple electrical gremlins bugging me. After having all the instruments out and then back in, I now have no flash to pass with the stalk and when I switch to hi-beams, the blue center light does not come on. Hi beams do come on, just not the dash light. Both worked previously. And my rheostat is stuck on the on. (spins with no change). Are these related? Any ideas?