Water Pressure Gauge

[Jason2tpa]

Hey boys...helping my pops with troubleshooting his water pressure gauge. He's got a '04 F150TLRC. Analog gauge, no needle movement. No issues with water pump function. I don't utilize a water pressure gauge on my rig so troubleshooting such is new for me. Where to start? Schematics and/or pics indicating key locations of system are welcomed.

[fairdeal]

on an '04 a water pressure gauge would be "mechanical" -
the instrument being an actual Bourden tube gauge -
and connected to the engine with a very long plastic tube
(almost exactly the same as the pitot tube speedometer)

the usual place for connection of the tube to the water jacket
is just below the ignition coils

"no needle movement" could be
- hose plugged with salt/gunk somewhere along its lenght
- hose pinched somewhere

[Jason2tpa]

on an '04 a water pressure gauge would be "mechanical" -
the instrument being an actual Bourden tube gauge -
and connected to the engine with a very long plastic tube
(almost exactly the same as the pitot tube speedometer)

the usual place for connection of the tube to the water jacket
is just below the ignition coils

"no needle movement" could be
- hose plugged with salt/gunk somewhere along its lenght
- hose pinched somewhere

Yes, you nailed with your description here ^^^. That's the one. And both of your troubleshooting suggestions were the exact same two I suggested to my pops. Good to know I'm on the right track. If the issue turns out to be corrosion, which I'm betting it is, does this mean the tube needs to be replaced? Or is there a nifty trick for getting the gunk out? Cause boy, replacing that tube would be a pain.

[fairdeal]

others may have nifty tricks

I imagine disconnecting at both ends, then applying a bit of air pressure at the gauge end

[DennisG01]

Just adding on a bit...

-- Attach a short length of new hose to the gauge and see if you can get the needle to move - verifying the gauge is fine... which most likely is.
-- Try adding a bit of air pressure from the engine end to see if you can get the needle to move. With a speedo pitot, I've been able to do this just by mouth pressure - don't know if that's enough for this application. If it moves, the clog is upstream.
-- Assuming similar to a speedo pitot, check for a clog from the point where the engine side of the hose attaches towards the water (into the engine block) - it's possible that the clog is right there at the fitting. Look and/or poke in there.
-- If air goes through the tube, but the needle doesn't move, look for broken tube (leak). If air doesn't go through, look for clog or pinch.
-- If no clog/pinch, and you haven't been able to blow the clog out with air pressure (both ends of hose loose), inject something like Salt Away or white vinegar from the gauge end (likely the high point?) and let it sit over night. Come back and try again the next day.

If you find there is a clog (in the hose), either continue with juice and pressure or replace hose. You don't necessarily have to run the new hose the same way as the old one - but try to avoid any dips along the way.

Edit: Couple more thoughts...

-- Run the engine with the hose disconnected. Does water come out the fitting?
-- Remove gauge from dash and attach directly to engine fitting with a short hose.

In the end, there's no one best way. The primary goal is to first eliminate variables and narrow down the search field. Then do whatever works best for you and your skill set.

[Jason2tpa]

Just adding on a bit...

-- Attach a short length of new hose to the gauge and see if you can get the needle to move - verifying the gauge is fine... which most likely is.
-- Try adding a bit of air pressure from the engine end to see if you can get the needle to move. With a speedo pitot, I've been able to do this just by mouth pressure - don't know if that's enough for this application. If it moves, the clog is upstream.
-- Assuming similar to a speedo pitot, check for a clog from the point where the engine side of the hose attaches towards the water (into the engine block) - it's possible that the clog is right there at the fitting. Look and/or poke in there.
-- If air goes through the tube, but the needle doesn't move, look for broken tube (leak). If air doesn't go through, look for clog or pinch.
-- If no clog/pinch, and you haven't been able to blow the clog out with air pressure (both ends of hose loose), inject something like Salt Away or white vinegar from the gauge end (likely the high point?) and let it sit over night. Come back and try again the next day.

If you find there is a clog (in the hose), either continue with juice and pressure or replace hose. You don't necessarily have to run the new hose the same way as the old one - but try to avoid any dips along the way.

Edit: Couple more thoughts...

-- Run the engine with the hose disconnected. Does water come out the fitting?
-- Remove gauge from dash and attach directly to engine fitting with a short hose.

In the end, there's no one best way. The primary goal is to first eliminate variables and narrow down the search field. Then do whatever works best for you and your skill set.

Great advice, thanks bud.