32-35 Hydrostatique Gauge Rebuild 101

[deuce lover]

Just did a gauge for a friend.It happened to be a 33-34 and NOS in the box. It sure looked great right out of the box,but -here we go. I removed the nut and plug on on the brass hex and surprise,it was plugged solid.Now these were shipped from the Mfg charged with the red fluid.Here are the series of pics I took from beginning to end of the restoration/service of it.

I first disassembled the gauge.Careful bending the little tabs or they will break.
You can see the corrosion from the leaking of the fluid.Fortunately is was isolated to the upper portion.
I cleaned the crud in the brass hex with dental tools from Ace Hdwe and removed the calibration rod.
First I used acetone and those small brushes to clean the hex and sight glass(which I pulled out slightly).
I couldn't get the acetone to flow thru easily from the hex to sight glass so used a diluted form of hydrochloric acid.That along with low air pressure from the compressor got it clear.More scrubbing cleaned the line completely.



I scraped the rust build up so would be easier to bead blast. I use a thick rubber fuel line hose capped off to protect the sight glass from damage during the blasting process.
I then paint the inside of the case/housing plus make a new white hard paper backing and clean the face,lens and bezel.Also I strongly suggest chasing the threads (5/16X24)on the hex so easier for the nut to go on.
Then reassembly.
Hopes this helps those that want to attempt to restore their own gauge.


PS This gauge being NOS,the face and chrome on bezel were in excellent condition.0000 steel wool works well cleaning the chrome in most cases.


Pic of the brushes I use.found on Ebay and syringe from Amazon.
Thread chaser set :https://www.ebay.com/itm/16187267754...Bk9SR7KDvuWwYg

[rockfla]

Fantastic work Sheldon. Thank you for the step by step tutorial and corresponding pictures.

[rockfla]

Fantastic work Sheldon. Thank you for the step by step tutorial and corresponding pictures. You are the “Man”!!

[TerryS]

Very nice work.
Thank you for the helping instructions with mine last fall.
Terry S

[ndnchf]

A very timely post. The gauge on my '35 does not work, getting it working is on my to-do list. I appreciate any and all guidance.

[petehoovie]

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Originally Posted by TerryS

Very nice work.
Thank you for the helping instructions with mine last fall.
Terry S

[FlatheadTed]

Nice Job , When I did my 35 I ran a copper tube along inside the dash so you can lower the whole unit down below the dash for topping up ,also above the glass tube there should be a little brass cap in the dash unit ,most are missing ,

[DavidG]

In the case of Sheldon's gauge and many like it, there's no opening in the top of the housing and hence no brass cap required to cover it up. Some have the opening and some do not. It is easiest to add fluid if your gauge has the opening.

[FlatheadTed]

OK Thank you ,you learn somthing every day

[Terry,OH]

Can use heavy white paper (The type that comes with a new shirt or so) to replace the paper backing of the sight glass. The old paper is usually discolored or stained.