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Topic: Dash Air Pressure Gauge Leak (Read 737 times) previous topic - next topic

Dash Air Pressure Gauge Leak

Starting to work on our new to us FT.  Amongst other things chasing down the proverbial air leaks.  I had one in the box under the step but I took it apart, recut the 1/4" tubing it and put it back to together and right now it's ok.

Powered it up this afternoon to check some things and heard a hiss behind the dash.  Air is leaking out of the top gauge assembly at the large nut.  I pulled it apart and put it back together hoping that action alone would fix it.  It did not... I can't tell if that is a standard o-ring (and if so what size) or a special style ring for that assembly.  The fact that it seats all the way by hand tells me it may need to be replaced as well. And I'm assuming using a pipe tape is not the best long term solution. Any thoughts on where to get a replacement?  Thank you.
Luke & Sandy (still many work years to go...)
1999 U320 36 Build #5387
2013 Jeep Wrangler Unlimited
Previous 1997 Winnebago Vectra Grand Tour 35WQ major interior remodel
Previous several SOB trailers, Class C, fifth wheels.

Re: Dash Air Pressure Gauge Leak

Reply #1 –

That is part of a solenoid valve - probably the one that sends air pressure to the Hadleys when you push the horn button.  If you can find a suitable sized replacement o-ring for the brass piece that would be the best/cheapest solution.

Or, if there is a part number on the solenoid assembly, you might find a complete new one online.  This look like it?

Amazon.com: Hadley Horns H00550C Air Horn Solenoid: Automotive

It is best to avoid using thread tape on air system fittings.  If you need to seal a threaded pipe connection, better to use a paste sealant.

Permatex makes a good product - available at most auto parts stores.

Amazon.com: Permatex 59235 High Temperature Thread Sealant, 50 ml Tube:...

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Dash Air Pressure Gauge Leak

Reply #2 –
So I called FT and they said they do not have parts that far back and they said if it was there they would either use something they found or put a new solenoid on.  They also could not tell me what solenoid it was.  Of course, the fact that it was Friday at 4:30 probably had something to do with it...

So I ordered two o-ring kits to have on hand.  In the interim, I stopped at Ace to get a stop-gap solution.  Of course, you have to hold your o-ring up and try to match it against a picture.  I came away with 3 that were close.  After opening you can see a big difference more clearly.  The bottom one in each picture is the original plastic(?) o-ring/gasket.  #53 was too big and moved freely.  #11 I did not even try as it is too thick.  #54 went on nicely and is either perfect or 95% good.  The huge air leak is gone but I still hear a little something if I get my ear down close.  I will get the soapy water out to see if it is still that connection or another one that was hiding behind the big air leak sound.  Maybe when I get the kits there will be a size that is 100% and I don't have to buy a new $45 solenoid.
Luke & Sandy (still many work years to go...)
1999 U320 36 Build #5387
2013 Jeep Wrangler Unlimited
Previous 1997 Winnebago Vectra Grand Tour 35WQ major interior remodel
Previous several SOB trailers, Class C, fifth wheels.

Re: Dash Air Pressure Gauge Leak

Reply #3 –
 You can measure through the plastic bag by a digital caliper on the plastic,  and setting to zero and then measure the item inside the bag.