Cleaning a blocked hydrostatic gauge

Have you tried using the HF spray gun cleaning brushes on it and either thinner or Denatured Alcohol?? Or is in down in the brass line?


Deuce Lover is the man....I am sure Sheldon will chime in!!!!
 
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I have had good luck soaking with lacquer thinner and a piece of .023 wire feed wire. Have restored many 32, 33 and 34 gauges. Don't be in a big hurry. A Q-tip with the cotton taken off will clean the inside of the glass tube and will work like a plunger to force the lacquer thinner through the small brass tube.
 
You might also try one of the cans of compressed air that they use to clean computer key boards, they come with a straw like WD40 or PB Blaster. Gentle pressure on the nozzle and you can get lighter blast of air as well!!!
 
I have done this a bunch of times.Sometimes that little line is totally plugged. Hydrochloric acid,Acetone will not clear it.If you can get compressed air thru it -even slightly the acid will clear it or has for me.There are times when I have had to replace the line and graft a new line then solder it back on the brass hex.Here is a pic.Renners corner sells a kit for $60.
s589187565737478790_p67_i2_w320.jpg B-9280
Description: FUEL GAUGE DASH HEAD UNIT REBUILD KIT
Comments: 13 pieces ( small clips are to repair broken tabs on bezel )
Application: 1932 pass. / comm. AND 1933 - 34 commercial
 

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I can not seem to get any of the cleaners, I have tried, through the brass tube. Lysol gel toilet bowl cleaner will clean the brass inside the hex tube but can not get it through the small brass tube due to blockage. Compressor can not blow through either. I will try the thinner and I do have some small diameter wire. Any other suggestions appreciated.
 
A while back this '35 gauge I repaired was completely blocked big time. I had to cut the line and clean it then replaced a section that was a larger dia tube to the hex and soldered it.Now I replace nearest to the 90 bend from the sight glass in same size tube to the brass hex.See post 5
 

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Long shot but maybe someone attempted a solder repair on the tube and plugged it? Look along it for solder that looks sloppy .
 
i have had good luck soaking with lacquer thinner and a piece of .023 wire feed wire. Have restored many 32, 33 and 34 gauges. Don't be in a big hurry. A q-tip with the cotton taken off will clean the inside of the glass tube and will work like a plunger to force the lacquer thinner through the small brass tube.

I was going to add my method but Deuce (post #3) beat me to it nearly word for word. Even down to the wire size!

Great minds?
 
I've had good results with phosphoric acid (metal prep) plus a wire for the brass tubing and a pipe cleaner for the glass tube.
 
You can unsolder the copper pipe of the brass hex and straighten it out, then drill it with a 2" piece of mig wire .,Flush it with solder fluid Hydrochloric acid and resolder ,cleaning it can help the colour to stay ,,your good to go ,
There's a old post on Shelly FB if you can find it .,
 
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Many years ago I found that using guitar strings as a wire to clean small orfices works great. They’re stiff and don’t break easily and you got various sizes.
 
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