Hydrostatic Gauge Fluid Colour

[Karl]

3 months ago I replaced the red fluid in the fuel gauge and already the fluid is fading. I got it from Classic and Exotic as I was told that theirs would not fade - The price was certainly exotic but it still fades. Does any one have a solution? I thought about just adding some red ink to the fluid but that might stain the inside of the glass tube ? I could use ATF but I'm not sure how well that works -Karl

[Steve Staysko]

Great I bought the King Seeley & Hobson Fuel Gauge Red Fluid from Classic & Exotic for my 34 Roadster and was told that sunlight would not cause it to fade I have not installed it yet in the fuel gauge and if it fades I will be disappointed because it wasnt cheap!

Originally Posted by Karl

3 months ago I replaced the red fluid in the fuel gauge and already the fluid is fading. I got it from Classic and Exotic as I was told that theirs would not fade - The price was certainly exotic but it still fades. Does any one have a solution? I thought about just adding some red ink to the fluid but that might stain the inside of the glass tube ? I could use ATF but I'm not sure how well that works -Karl

[rbone]

I put the fluid from Obsolete Ford Parts in my '34 about a year ago and it is still as red as the day I put it in.

[Brian]

Don't know if it helps, but the original liquid, tetra-bromo-ethane was tinted with 'Durant" scarlet dye.

[Karl]

Originally Posted by rbone

I put the fluid from Obsolete Ford Parts in my '34 about a year ago and it is still as red as the day I put it in.

Might try them next time - Flathead Ted has found that the fluid from Macs worked well so I guess that is another option-Karl

[Ian NZ]

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I have been trying different fluids for some time now, and Lawson Cox remarked some time ago about using red automatic transmission fluid so I have been using that, not very accurate but it looks good.
Karl, give Steve Trott in Tauranga a ring and see what they use in the Packards he has restored, which I believe have the same hydrostatic fuel gauge, 06 835 2452 I think that is the correct phone number. it could be interesting.
Apparently the fluids available now have different ingredient to the original fluid, and the chemists are now not allowed to make up the fluid to original specifications. or do not want too.

[Brian]

Yeah, that original liquid is not only corrosive, but I imagine it's as carcinogenic as hell. The important thing is that the specific gravity is 2.95 in order to maintain accuracy of the gauge.

[outlaw]

I might be off base here, but at work we use some hydraulic fluids specific to certain Caterpillar equipment that is so light in color it is almost clear. We have our Chevron bulk distributer add dye to the hydraulic fluid so that we can see it in the sight glasses & if we develop leaks. From what they have told me it is also used to color antifreeze. We have had them use both red & blue dye in hydraulic oil. Maybe this can be added to the fluid used in the fuel gage. If you have a bulk Chevron or any bulk fuel/oil distributers in your area it might not hurt to inquire if they have a compatible dye that would work. Just an idea. Hope this helps. Bill

[FlatheadTed]

You can just see the red ,Not sure why it holds its colour its been in a long time from Macs ,could be that the tube was well cleaned out ,

[Ian NZ]

Has anybody ever thought about making a little colored float to sit on top of the fluid.
I think you will find that the fluid that is made nowdays would be only available from one distributor, the demand would not be there. I had a 32 Dual, fuel temperature gauge fully rebuilt by a reputable U.S. firm a few years ago and the red fluid in the temperature gauge has now gone clear as well so it must have the same type of fluid, no wonder N.O.S fluid working Temperature gauges fetch a high price.

[VA_34-40]

Would the test balls in an antifreeze tester fit with the tube and move without binding? We had some MAC fluid that lasted about 3 years before it started to fade to clear.

[Ian NZ]

A round test ball out of the right material would best as the round shape would have less surface area on the glass than a cylinderical round shape, I wonder what sort of material you could make a ball out of for this liquid because all you would have to do is drop the ball in.

[earlyride]

I used red gauge oil, it has a specific gravity of .826 not sure if that's correct for a hydro static gas gauge, but it looks better than any other alternative and it's cheap and plentiful or it was when I got it, should it fade, I'll just replace it.

[Brian]

'I used red gauge oil, it has a specific gravity of .826 not sure if that's correct for a hydro static gas gauge, but it looks better than any other alternative and it's cheap and plentiful or it was when I got it, should it fade, I'll just replace it.'

"The important thing is that the specific gravity is 2.95 in order to maintain accuracy of the gauge."

This is where we need an Einstein; there must be a way to calibrate the sender to the gauge to suit the specific gravity. The sender appears to be a complex affair with a multitude of cups and tubes. However, from what I understand, this is a simple manometer; which is the most accurate method of reading pressure differential, which is all its doing. Also, its an old Ford and everything is simple in those things. [If you can understand the concept]
Earlyride- What did you use your 'red gauge oil in?

[Ian NZ]

Originally Posted by earlyride

I used red gauge oil, it has a specific gravity of .826 not sure if that's correct for a hydro static gas gauge, but it looks better than any other alternative and it's cheap and plentiful or it was when I got it, should it fade, I'll just replace it.

What I have done I placed a low pressure adjustable air regulator in the air line to gauge which works with the automatic transmission oil which is not a true red color, which I reach under the dashboard and adjust when I am travelling after a petrol fill, and it does work but is very sensitive, what I will do is purchase some red gauge oil and try that. 'Early ride what sort of readings to you get with the red gauge oil?

[earlyride]

My gas gauge readings are all over the place, not accurate at all, but I never really set it up originally to begin with. As long as I see red in the sight glass I know I've got fuel and for me anyway that's ok

[FlatheadTed]

When filling a old gauge soak the inner tube with hydrochloric acid ,this may remove contaminant that effects the colour ,Ted

[Ian NZ]

Apparently if you tint the faded Tetra- Bromo- Ethane fluid with Sudan Red dye it stays with the correct colour the catch is where would you be able to obtain this dye.

[britman]

Didn't know you could refill the tube. whats the proceedure? Had my original gauge professionally rebuild--so far no problems.

[barnfind]

RE: the original liquid, tetra-bromo-ethane was tinted with 'Durant" scarlet dye

If you want to become a supplier or vendor of tetra-bromo-ethane,
looks like .5 Liter is only $221 at:
https://www.fishersci.com/shop/produ...cal-2/p-195267
Color is light yellow.