Smith's fuel pressure gauge installation issue

mjhcobra · #1 (**permalink**) 12-23-2010, 10:27 PM

When I got the gauge package, I also got a gauge protector for the fuel pressure gauge. I was told this was necessary to keep fuel out of the cockpit. I assume then this little unit mounts on the firewall in the engine compartment. How does it then connect to the gauge (metal or plastic line) and how does it work. Again I assume that there is oil in the line between the protector and the gauge. Comments???

Roscoe · #2 (**permalink**) 12-24-2010, 06:37 AM

I have the Sport Comp fuel pressure gauge and isolator. The isolator contains propylene glycol. It mounts on the firewall.

mickmate · #3 (**permalink**) 12-24-2010, 06:54 AM

The isolator just has a diaphram in it to transmit fluid pressure through the glycol. The guage side has the glycol and metal braided line, the other end is right to fuel supply. That should have a braided line also.

zrayr · #4 (**permalink**) 12-24-2010, 08:07 AM

Mallory sells a nice isolator also. It is somewhat more compact than the AutoMeter unit shown above. I have used both of them & they work equally fine.

http://www.summitracing.com/parts/MAA-29806/

Z.

mjhcobra · #5 (**permalink**) 12-24-2010, 06:13 PM

So I assume you connect the tube/hose to the gauge and fill the tube from the gauge to the protector with the glycol and fill it as much as it will hold. What other chemicals or oils can be used?

zrayr · #6 (**permalink**) 12-24-2010, 06:54 PM

Quote:

Originally Posted by mjhcobra

So I assume you connect the tube/hose to the gauge and fill the tube from the gauge to the protector with the glycol and fill it as much as it will hold. What other chemicals or oils can be used?

The Autometer unit comes already with the braided hose filled and attached to the gauge, you just top off the isolator with some more antifreeze and attach the hose to it. The Mallory isolator is easy to install as well.

I don't see the need to try other fluids. Antifreeze works fine and will evaporate or clean up easily if spilled.

Z.

mickmate · #7 (**permalink**) 12-24-2010, 06:55 PM

The Autometer came filled and plugged on the isolator and the guage line. I didn't think you'd be able to but if you keep them pointing up when you unplug them and screw them together quick you lose very little. I had mine completely apart to powdercoat and tone down the color so it needed completely refilling which wasn't hard. I believe glycol is all they recommend.