Just installed an ISSPRO mechanical fuel gauge with isolator. But Now I'm having second thoughts about the isolator. I'm running biodiesel B99 most of the time. Is that clear tubing okay with bio? Are those Parker push in compression fittings okay, or should I switch to the threaded type compression fittings? I don't think I can sleep at night wondering if antifreeze is leaking back into the the fuel via a leak in the isolator.

 

I ran mine for approx 2000hrs with just a needle valve and a small fuel line into the cab(stainless steel), no leaks or issues, cant speak for bio or an isolator, as I never used one, have read that they do fail thou

 

i also had an isolator to install. i decided to NOT use it and just ran the clear/opaque tubing into the cab. if it was gasoline or a harsher fuel you would run into problems. diesel is very similar to oil and that line will perfectly fine running diesel. don't be worried about the line failing, just make sure the connections are good.

i also run a needle valve like 'nickg'. the valve is cracked just enough to get an accurate reading, but not enough to let the pulsations thru (at least not enough to make it palpable)

 

Isolators all seem to fail or have trouble.
If already installed it...see how long it lasts, but I'd plan on removing it when the time comes.
But if loosing sleep..... do it now!

Needle Valve/Shut-off works very well for safety in case you get diesel leak in cab.... and even better for protecting the life of the gauge.
Full fuel pressure will start your gauge vibrating and internally hemmeraging!
The needle valve allows you to reduce pressure to the gauge. Takes a VERY small flow to gauge for accurate reading, since it's a closed system.
I shut mine down completely... then open the valve about 1/8 turn! Less is better, in this case!

RJ

 

On my 2000, I ran diesel rated fuel line right up to the gauge with a needle valve after having many problems with that clear line cracking and leaking. I threw the isolator away also, what a nightmare that was. I did not notice the smell, but wifey did not like it and it leaked ALL THE TIME. The compression fitting would crack the line. Just get some good diesel rated, rubber fuel line (FYI its not cheap) and good hose clamps and all will be well.