Best way to bleed an isolator?

[moose52]

Whats the best way to bleed an isolator for a fuel gage? Did a search but nothing came up. Wondering if I should put a T fitting in close to either the gage or the isolator? Also what are people running on the gauge/isolator side? Glycol mix? I have heard some people use mineral oil? Steve

[speedbuggy]

I take an empty rear end oil bottle that has the nipple snout on it. Then use electric tape to attach a small diameter nylon flex tube (the same kind of tubing that you get with a street-type oil pressure gauge) to the bottle snout. Fill the bottle with 50/50 antifreeze. You are trying to fix this so that when you squeeze the bottle, fluid comes out the end of the tubing. Make sure your tubing is longer than the line you've run from the isolator to the gauge (assuming you are using -4 line or some such for the actual pressure line).

Hook up your -4 line at the gauge. Run the nylon tube inside the -4 line from the open isolator end all the way down to the back of the gauge. Hold the bottle higher than the gauge and squeeze the bottle, filling the -4 line from the bottom up until fluid comes out the top at the isolator end. Now remove the nylon tube, top off the -4 line and screw it onto the back of the isolator. Try not to spill too much out when you're attaching the isolator, but a little bit is ok.

[moose52]

That is an excellent idea! My fear was having to undo it at the gauge. It's a tight fit working behind the dash and I tend to do work back ther be feel rather the "seeing" what I'm doing. Plus I think I have everything you mentioned in the shop. Thanks for the help.Steve

[speedbuggy]

Also, be sure to fill the back side of the isolator before connecting the line.