Need help with FP Isolator- How to fill w/ antifreeze??

[7FA]

Doing a FP gauge install this weekend. Almost done, but can't figure out the best way to fill the gauge side with antifreeze!!!



Does the whole line and isolator need to be filled up, or just the isolator cavity??





Any tips on how to do this??



Thanks!!

 

[JStieger]

7FA-



Check your email! Anyhow here's what I sent you:

Check this out:



http://piersdiesel.com/TechIsolator.htm



You can also use a hypodermic needle bought from any drugstore. If I remember correctly, if the tubing run is less than 6 feet then you don't really need antifreeze in the line since whatver you add to the isolator should be enough. I ended up only filling half the tubing over 3-hours and called it good and haven't looked back since!

 

[Jengle]

I was also told by the people I bought the guages from that you didn't need to fill the tube, so I didn't. I just filled the isolator, and called it good. Been operating 3yrs now, and no issues whatsoever. Gauge reads steady, no noise or funky readings. Haven't touched it since the install.

 

[GOTSOOT]

just like they said above, use a hypo, and fill it, make sure that the ga. end is disconnected and use a rag to catch any that runs out and you can get almost completely filled, w/only a small amount of air in the line. we tried to not use any thing, at first and could get no reading, it being less than 6`.

 

[jjdiesel]

I was also told by the people I bought the guages from that you didn't need to fill the tube, so I didn't. I just filled the isolator, and called it good. Been operating 3yrs now, and no issues whatsoever. Gauge reads steady, no noise or funky readings. Haven't touched it since the install.

Same here... did not mess with a hypo, just fill the isolator and you are good to go!

 

[Mark Craig]

Jengle,



You're not getting an accurate signal if you have that much air in the line, air compresses, fluids don't and the gauge is going to read way off. Fill it up, I bet you see a difference in gauge operation.



Mark @ DPPI

 

[7FA]

Thanks for all the replies. . Looks like I will try to fill it up!!

 

[john3976]

According to both DiPricol and ISSPRO in their instructions for their fuel pressure gauges when used with an isolator if you have a run under six feet long you do not need to fill the tube with antifreeze.



I only filled my isolator with antifreeze and my fuel pressure runs at 9 pounds at idle and between 8 and nine pounds when crusing down the road. If I stand on it I can pull the fuel pressure down to 4 to 5 pounds.



Can any one tell me if my numbers are way off?

 

[jjdiesel]

John... I also have Isspro gauges and like you, mine is at about 7-8 cruising, can pull down to about 3-4 honkin' on it