Pesky water separator

[RSchanz]

So the seemingly classic thing happened where the "water in fuel" light came on for the first time and I pulled the drain plunger which then has led to hard starts. I put a nut and bolt in the line to hopefully keep air from getting in and it didn't help. Drove the truck a few times and the light came back on now. I've read Mel's sticky about cleaning the separator but before doing that I want to rule out the possibility of just having bad fuel. I was thinking I would drain the front tank and fill it up with fuel from a different station and see if that fixes it. If the fuel were the cause and not the separator would I be having more issues than just starting? I would imagine this could be a combo of garbage fuel and also an air intrusion from pulling the drain plunger.

 

[MadMac]

Without telling the length story about my Racor replacement finally fixing my starting problems… I’ll make the observation that I have not seen mention about how to test the separator itself, vacuum loss in my case.

I’m sure someone has documented some simple way to do this, I’ve just not seen one. I would think disconnecting input and output, locking them off and then applying a small amount of air pressure, with a pressure gauge inline - would show such a thing. No idea how much pressure might damage the unit.

Just seems that might be one of the steps in a DX... not knowing how they actually work - I could be completely off base.

 

[RSchanz]

I figure cleaning it wouldn't hurt anyways but neither would replacing it I guess...

 

[Greenie]

I have 3 diesel engines and have not seen even a drop of water in filters or bowls for years. I attribute this to using an additive that emulsifies water in fuel so it doesn't need to be drained - it runs through the pump and injectors and is vaporized in the combustion chamber. I've used this additive almost since this truck was new and the original injector pump and injectors lasted over 250,000 miles with emulsified water running through the entire system rather than collecting water at a low point. I've used Stanadyne Performance Formula all these years. If you read the Stanadyne Performance Formula literature it claims it helps demulsify water so it's trapped in filters but I've not found that to be the case. Using this additive will leave water sumps empty.

 

[RSchanz]

I have 3 diesel engines and have not seen even a drop of water in filters or bowls for years. I attribute this to using an additive that emulsifies water in fuel so it doesn't need to be drained - it runs through the pump and injectors and is vaporized in the combustion chamber. I've used this additive almost since this truck was new and the original injector pump and injectors lasted over 250,000 miles with emulsified water running through the entire system rather than collecting water at a low point. I've used Stanadyne Performance Formula all these years. If you read the Stanadyne Performance Formula literature it claims it helps demulsify water so it's trapped in filters but I've not found that to be the case. Using this additive will leave water sumps empty.

Interesting, I'm always using a an additive and lately I've been using Hotshots secret everyday additive. It's not my first choice but easy to find near me.

 

[Cubey]

Interesting, I'm always using a an additive and lately I've been using Hotshots secret everyday additive. It's not my first choice but easy to find near me.

You can get big bottles of it for good prices at truck stops and refill the measuring bottle.

 

[Old Goat]

I changed out the factory water separator next to the Booster, to a Racor 500FG.

https://www.parker.com/content/dam/Parker-com/Literature/Racor/Tech_Install/15332_500FG_Turbine_Series.pdf

I didn`t buy it new, actually found it on a 85 6.9 at PNP and a nice well made bracket for the mounting.
It is mounted on the tab on the inner fender the Cruise Control thing bolts to.
I don`t have CC.
Has a 2 micron replaceable filter inside.


Goat

 

[RSchanz]

The light came back on and I tried pulling the plunger and nothing came out. The air intrusion became so bad the truck wouldn't idle anymore. So I took this stupid little thing off and took it apart and cleaned it. I feel like the plunger wasn't working right or the hose was just plugged because as soon as I took the drain line off that thing was draining like crazy. Inside didn't look too dirty but the sock never came out and appears to just be stuck inside the separator. I know this because I can see it along the inside and with a flashlight can get a better view.

Has anyone taken these apart per Agnem's write up and not bothered putting a new sock filter on?

The Stanadyne Water Seperator Exposed

We all know that the factory 6.9 water separator is prone to letting air in the fuel system, and that a common remedy is to either remove it all together, or plug up the drain hose. What nobody has been doing that I am aware of, is repairing it, and it may be as simple as cleaning it. ;Sweet...

www.oilburners.net

 

[RSchanz]

So that there is some conclusion for anyone who finds this, I put it back together without the sock. The air leak went away and the truck runs fine. The light stayed on for the rest of that tank plus another one but it's now off. Eventually I might swap this out for a Racor filter but seems fine now.

 

[Kdo58]

Why not just use a wix filter?

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[Cubey]

Why not just use a wix filter?

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6.9 can't use that, different threads.