Fuel Pressure Isolator question

[KIseminger]

Just installed my gauges... . they look awesome!



Just need to hook up the isolator for the fuel pressure gauge. In the instructions it says to fill up the fuel side w/ glycol then after the line is hooked up I need to open up the bleed screw with the ignition on until fuel comes out.



I do not hve any glycol. Is it entirely necessary to put glycol in it? It seems to me that if I just let the air bleed out it will essentialy do the same thing.



Has anyone had experience with this? Please let me know SOON. I want to get this done tonight.

 

[KLockliear]

Glycol = coolant. Use that because when it gets cold, it won't freeze.

 

[paulb]

Are you sure it said to fill the fuel side? I have the same gauges, and in my instructions it had me fill the gauge side. I would not put glycol in the fuel side. I'm not sure what the result would be if it got to the VP44, but I don't think it would be good.



Paul

 

[KIseminger]

Just read the directions again... ... . perhaps I should have read those a bit closer.



Keith, I was thinking about the kind of glycol they put in some gauges. After reading the directions again I understand it better.

 

[KLockliear]

Like a liquid filled gauge? That's silicone liquid in there. Fuel goes to the isolator, then glycol from the isolator to the gauge.

 

[KIseminger]

Hmmmm... ..... I'll just stop right there. I'm digging my self in a little deeper.



Got the isolator in though. Gauge works great.

 

[Jengle]

I put mine in and the directions said to put the glycol(coolant)in the gauge side and fill the line to the gauge. I got confused about how to do that and called DPP, where I bought the gauges and isolator and he said they were changing the directions to only fill the isolator with the coolant. That's what I did and have no coolant going to the gauge, but it works fine. No noise and the needle is steady. I didn't add any fuel to the fuel side, just cycling the key and then running it will fill that side.

 

[clawson]

Will diesel fuel hurt isspro guages? I am thinking about getting rid of my isolater because it never reads right. I have been through 2 isolators.



Chris

 

[RHARVEY]

I have installed 3 isolators and have hated all 3. Two of them have not come back but the 3rd is on my wifes 2k and it started having problems. When I installed it. . I did the coolant and water mixture(gauge side) it worked great. After about 2 months... I noticed a drop in pressure. . so I bled the line again to get all the air out of the line. . pressure came back up. Two months later. . it did the same thing. I tool the isolator off and did a straight line into the gauge. I didnt use the standard steel line this time, I used a new setup made up with Aeroquip fittings and their line with a shutoff valve under the hood. I have the shutoff valve just cracked open for the fuel to pressurize the system(gauge) but not open enough for the pulsation of the 44 to kill the gauge. The gauge is responsive so I know there is enough fuel going to the gauge. .

These isolators are a major pain!



Rick

 

[FJfonda]

I used a Marsh Bellofram industrial unit on my '99. Plumbed it with a grease gun extension flex line going to the fuel filter tap and used line clamps to attach the isolator to the brake lines. (The 1st attempt was to mount it directly to the filter housing but the diesel vibrations kept breaking the fittings. ) I filled the gage side per the mfg instructions using 50/50 antifreeze solution. The fuel side of the isolator has a bleeder screw which came in REAL handy during filter changes.

Not filling the gage side will result in diaphragm failure due to overextension of the diaphragm ( air is compressible and liquid isn't). I too had problems in the beginning but it was related to the cheap ferrules that come in the gage hook up kits. These ferrules did not crush evenly and leaked at the fitting connection. Once I started using higher quality fittings the problems went away.

This little adventure cost me a fuel pump as the gage actually read lower than actual.

 

[KLockliear]

Just gotta find the right isolator. We tested a whole bunch before we found one that works well.

 

[KIseminger]

Which one did you find that works?

 

[KLockliear]

The one we sell.

 

[KIseminger]

Originally posted by KLockliear

The one we sell.

Gee, thanks... ... . a bit secretive, aren't we?

 

[KLockliear]

Secretive? No - but after the R&D time, trial costs of all these isolators that we tested, do you think I should just give out the info so we get cut out of the loop and all that R&D was for naught?

 

[clawson]

So will diesel fuel hurt isspro guages?

 

[jtisdale]

Originally posted by KLockliear

The one we sell.

:-laf

I have had an Autometer fp w/ isolator in for almost two years. It has always been accurate within a half a pound when tested against my other test gauge. Now that I have installed my PE, the needle resides where the 18 should be on the face. (too bad its only a 15lb gauge) So far no trouble ... yet. Now that I have opened my big mouth it will probably take a dive.

 

[KIseminger]

Originally posted by jtisdale

:-laf

I have had an Autometer fp w/ isolator in for almost two years.

I am assuming that the isolator is an Autometer brand? I have a Bellofram for my pricols. I'll have to look in to that when mine takes a dive. Thanks for the info.

 

[jtisdale]

Yes, it is autometer also.

 

[FJfonda]

The Marsh Belloframs come with different diaphrams. I found the nitrile diaphram worked the best. Lasted for over 2 years for me... . my original was neoprene (I think) and did not hold up.