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Vacuum gauge for Racor fuel filter

Jul 25, 2007
35
Catalina 310 Middle River, MD
Has anybody installed a vacuum gauge to indicate status of the standard Racor 225 fuel filter? If so, any tips (parts, where to locate the gauge, etc.) ?
 
Jan 4, 2006
2,655
Hunter 310 Island Hunter West Vancouver, B.C.
Has anybody installed a vacuum gauge to indicate status of the standard Racor 225 fuel filter? If so, any tips (parts, where to locate the gauge, etc.) ?
Looking at the Racor 225 port configuration, attach it to one of the two outlet ports. This is how I did my Racor 110 fuel filter.

DSC_0511_2Fotor.jpg
 
Oct 22, 2014
11,359
CAL 35 Cruiser Portland OR, moored EVERETT WA
You can use the same method as the I did on my Racor 500 (see image).
The gauge can be found at a Hose or Fuel line outlet in your area.
Here is an example at the Advance Auto Parts in Middle River (http://shop.advanceautoparts.com/p/mityvac-replacement-vacuum-gauge-mit6171/22984960-P?searchTerm=vacuum+gauge)
I found a gauge at a hose distributor servicing Trucks for about $25. I got a gauge that was oil filled. It dampens the needle movement when the engine is running so you can read the level of vacuum.
Parts needed include a Outlet fitting for the Racor. My Racor had a 3/4" Outlet - Bought the adapter at West Marine . The one I bought has a 1/4" female outlet that matches my fuel line fitting.
Here is an example:
Racor Fuel Fitting For 500 Series Fuel Filter / Water Separators
  • Thread / Thread Size: 3/4 SAE x 1/4 NPTF Female
  • Material: Steel
  • Straight Fitting

$5.99 Model #: 911-08-F4 Note there is an O ring that seals the fitting in the Racor housing.
Your filter may use a different thread size.

Then a 1/4" Male/Female/Female T fitting. This assumes your fuel line has a 1/4" male fitting.

Anderson Metals Brass Pipe Fitting, Barstock Street Tee, 1/4" Female Pipe x 1/4" Male Pipe x 1/4"
Female Pipe upload_2016-8-14_10-21-35.png


Here is a picture of my finished system. Works great. shows vacuum of "3" when clean filter. If the filter gets clogged that number will go up. Not sure how high. Will have to see.
FilterNew.jpg

 
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Likes: JamesG161
Oct 22, 2014
11,359
CAL 35 Cruiser Portland OR, moored EVERETT WA
PaulJ, sitting there all set up it was too pretty not to snap a picture. Installed it is working as anticipated. Very pleased.
 
Feb 6, 1998
11,117
Canadian Sailcraft 36T Casco Bay, ME
Guys,

I would strongly urge you to purchase vacuum gauges that use a "drag needle". Vacuum can really only be observed while under load at your max cruise RPM. This means crawling down into the engine room to look at the gauge when you're crusing. Not fun. You could also do what many power boats do a mount a gauge at the panel but that is a PITA.

The alternative is to use a fluid filled "drag needle" vacuum gauge. I have been using them for about 15+ years. Racor now finally recognizes the inherent issues with non drag needle gauges and now offers one $$$. The SBO store also has an alternative drag needle model. Drag Needle Vacuum Gauge - SBO Store

Once installed you can check on the max vacuum ever pulled at any time even with the engine off.. You will quickly develop a sense for where a new filter should be and then can assess replacement interval via the drag needle. I simply will not install a non-drag needle gauge for any of my customers as it is simply taking their money for no no actual benefit. I have far too many customers, with installed vacuum gauges, that had no clue you need to check on them at cruise RPM or better while under load. They are essentially very expensive placebos that have been telling them nothing when they look at it at idle.. While an at idle measurement can be used, it forces one to push the fuel filter life until the engine begins losing power. You then reduce to idle and mark the position the gauge reads at idle. Pushing the filter to the point of restricting the engine can be dangerous and is not generally advised.

This is the drag needle gauge on my fuel polishing circuit...
 

Tom J

.
Sep 30, 2008
1,519
Catalina 310 Quincy, MA
Has anybody installed a vacuum gauge to indicate status of the standard Racor 225 fuel filter? If so, any tips (parts, where to locate the gauge, etc.) ?
I installed the Racor vacuum gauge kit just above the small hatch for the engine raw water through-hull. It's a short run from the filter to the gauge, and it's easy enough to step down the companionway stairs to check it at cruise RPM's as Maine Sail suggested. The drag needle Maine Sail suggested would be ideal, though.
 
Jul 25, 2007
35
Catalina 310 Middle River, MD
What are typical vacuum readings with a clean 2-micron filter and typical cruising rmp under load ?
 
Oct 22, 2014
11,359
CAL 35 Cruiser Portland OR, moored EVERETT WA
Weller, With a new filter I see 1 or 1.5 on the fluid filled gage while running at 2300 rpm. A low reading means the filter is letting fuel flow and your fuel is clean. I use a 30 micron on my Racor.
Let the fuel develop critters and they will clog the filter. It looks like the filter is full of coffee grounds. Then you will see a 10 or higher... Much higher and the engine will be starved for fuel and she will just quit. When I see 10 on the gauge I am changing the filter.

Helped a friend put a gauge on his system and we got the motor started by was seeing 0 on the gauge. Looking closely we could see air bubbles in the fuel. Shut down and find the leak. sealed the leak and was rewarded with a vacuum reading of 1.5.
 
May 20, 2016
2,883
Catalina 36 MK1 94 Everett, WA
I respectfully disagree with you can only tell when at full ( or operating) rpm. I think the best time to check vacuume is at the dock before you start the engine. To do this you need to route all flow back to the tank. Only by checking vacuume thru the filter without interaction with the engine can you really tell the state of your filters. Having the engine running introduces too many variables.
 
Feb 6, 1998
11,117
Canadian Sailcraft 36T Casco Bay, ME
I respectfully disagree with you can only tell when at full ( or operating) rpm. I think the best time to check vacuume is at the dock before you start the engine. To do this you need to route all flow back to the tank. Only by checking vacuume thru the filter without interaction with the engine can you really tell the state of your filters. Having the engine running introduces too many variables.
You'd not be disagreeing with me you'd be disagreeing with Racor....

Racor:
"Monitoring the black needle to ensure it does not reach this setting has been difficult as the operator must observe the needle while the engine is running at service speed (the gauge is not always mounted in a location that is easy to monitor). Now Racor introduces a tell-tale needle that follows the black needle as it indicates increasing vacuum. When the engine is shut down, the black needle will reset to zero and the red tell-tale needle will stay at the highest reading. Now the operator can monitor system restriction results without the engine operating."
 
Feb 6, 1998
11,117
Canadian Sailcraft 36T Casco Bay, ME
What are typical vacuum readings with a clean 2-micron filter and typical cruising rmp under load ?
A 2μm filter really should not be used as a primary or secondary filter, unless you have a brand new common rail/electronic diesel... The use of a 2μm filter "will shorten fuel pump life" (Westerbeke's words not mine). I see this in the field on a pretty regular basis. On almost ever fuel pump I replace I find a 2μm filter in the system. In early april it was a failed diaphragham in a Yanmar. Owner had a 2μm and is on his third fuel pump. I have that identical engine with fuel pumps in excess of 30 years old still going strong but no 2μm filters.. When I see these pump failures the owner is sometimes on their second or third pump. I have small diesel engines out there that have in excess of 12,000 hours on them that have run 30μm primaries for over 30 years.

Westerbeke / Universal Recommendations:
For fuel hose runs of 10' or less, from tank to the fuel lift pump, Westerbeke / Universal recommends that the primary filter should be a 10μm or 30μm. For fuel runs of more than 10', between the tank and the fuel lift pump, the filter should be a 30μm. Westerbeke / Universal does not recommend running 2μm filters in these mechanical style engines.... All this info is verbatim from Westerbeke/Universal's engineer Bob B.
 
Jul 25, 2007
35
Catalina 310 Middle River, MD
Thanks all. I installed a new vauge and am reading zero at cruise rmp under load. Will check for leaks and also replace that 2-micron filter with a larger pore filter.
 
Oct 22, 2014
11,359
CAL 35 Cruiser Portland OR, moored EVERETT WA
More then you wanted to know...
From Parker/Racor
"A micron rating for a fluid filter is a generalized
way of indicating the ability of the filter to remove
contaminants by the size of the particles....
The micron rating does not properly or fully
describe either the efficiency or the contaminant-
holding capacity of the filter."​
https://www.parker.com/literature/Racor/Mobile_The_Micron_Rating.pdf
 
Jun 7, 2016
125
Catalina C30 Warwick
I want to install a vac gauge on my Racor 215 can anyone tell me where the gauge actually connects into the housing?
20200105_103407.jpg
 
May 20, 2016
2,883
Catalina 36 MK1 94 Everett, WA
On one of the out holes. If you don’t have a open out - install a Tee. Looks like plugged hole in your photo

Assumes you have the pump between filter and engine and not between filter and tank ( incorrect position)

Also vacuum gauges are about $12 at a hydronic shop. Racers gauges are way over priced.
 
May 20, 2016
2,883
Catalina 36 MK1 94 Everett, WA
Thanks all. I installed a new vauge and am reading zero at cruise rmp under load. Will check for leaks and also replace that 2-micron filter with a larger pore filter.
Likely the gauge is on the input rather than the output side of the filter.
 
Oct 22, 2014
11,359
CAL 35 Cruiser Portland OR, moored EVERETT WA
Les is smack on.

You are installing a vacuum gage. Think about it. The only time you should see a vacuum is when the pump on the engine is sucking for all it's worth trying to get fuel to feed the engine and something is blocking the straw it is sucking on.

When I am sucking on a strawberry milk shake it usually is a great big strawberry at the bottom of the straw stopping the shake from filling my mouth.

For the fuel pump when the gage is between the engine pump and the filter, it would be gunk stuck in the filter clogging up the works. Some gages have color code... Not needed. You look at the gage and if it reads 2-5 you are ok You got fuel flowing. If it reads "0" either the engine is off or you got an air leak. If the gage moves up to 10, it is time to take a look at the fuel filter.