Fuel filters RR-Universal-details learned

Oct 9, 2008
1,742
Bristol 29.9 Dana Point
I've changed fuel filters before. This is the 1st time on a Universal M-18 (Other models are similar or the same). In the past, I've had it done by the yard. These are the details learned, some of which are not in the service manual or elsewhere:

The Racor cover gasket and T-handle gasket are included with the Racor filter. They're hidden in a sub package.

The fuel drain at the bottom of the glass is clogged, or there is a vacuum, if the fuel does not start to drain immediately when loosening the drain.

No fuel escapes from the top of the racor, if the fuel shutoff valve is closed. However, fuel will be in the nooks in the cover, so remove with a rag. Also, fuel may not drain out of the glass if the fuel shutoff is closed and the cover is on. Loosen the cover 1st then open the drain. If it hasn't been drained, still no fuel will escape at the top when you open the cover, but the fuel will be at the brim.

If you have an older filter in the Racor, there may be a rubber spacer on the bottom that needs to be discarded when using the new style filter.

The old filters had a colored body, indicating the mic rating. The new ones have colored lettering indicating the rating. All the bodies are now tan.

Keep a coffee can or other receptacle under the Racor apparatus, in case fuel escapes or dribbles from the drain after closing.

The new filter is a tight, precise fit. Don't force, it will slide on easily with the right vertical angle.

On the engine, the spin-on filter looses about a tablespoon of fuel when you unscrew it level. Keep a rag under.

There is a lot of air in the system after everything is buttoned up. It takes about a full minute with the electric fuel pump on to bleed. You can hear the air escaping.

The bleed bolt at the injector pump did not bleed any air. Fuel escaped immediately following breaking the bolt loose.

The engine started right up with no issues, as if there had not been a breach of the fuel system.

I didn't spill a drop. It all went into the coffee cans and\or rags. Although, I can see where fuel could easily escape into the bilge if not anticipated.

It took 2 hours of analyzing, reading internet, the service manual, etc. Hopefully these notes will help another to do it faster :)
 

capta

.
Jun 4, 2009
5,073
Pearson 530 Admiralty Bay, Bequia SVG
Oops, you forgot one pretty important thing. Always lubricate the gaskets on filters with a drop of engine oil. I usually get it off the dip stick. I do this with all filters including spins-ons and o-rings, unless the o-rings come with something specific or instructions stipulating something else.
 
Oct 9, 2008
1,742
Bristol 29.9 Dana Point
Oops, you forgot one pretty important thing. Always lubricate the gaskets on filters with a drop of engine oil. I usually get it off the dip stick. I do this with all filters including spins-ons and o-rings, unless the o-rings come with something specific or instructions stipulating something else.
Yes, good add. The manual says use clean diesel (which I obtained from the old spin-on), but it seems clean oil would do the same.

This wasn't really a step-by step. It's just things I discovered about this particular engine that I thought might be useful.
 
Oct 17, 2011
2,809
Ericson 29 Southport..
I can tell ya another small 'trick'. Some of you fuel-heads will know this, but a product called Power Service is what I sometimes use to prime a filter. It's a good diesel additive anyway, cleans injectors, blah, blah, blah. It's not as stinky as diesel on your hands, stows nicely on the boat in its own container, etc. It's just a win-win for the old fueler. I've been using this stuff for years..
 
Oct 9, 2008
1,742
Bristol 29.9 Dana Point
I can tell ya another small 'trick'. Some of you fuel-heads will know this, but a product called Power Service is what I sometimes use to prime a filter. It's a good diesel additive anyway, cleans injectors, blah, blah, blah. It's not as stinky as diesel on your hands, stows nicely on the boat in its own container, etc. It's just a win-win for the old fueler. I've been using this stuff for years..
I'm glad you mentioned that. Good for the systems that need priming.

And, it brings up another technical point: On mine and I think the newer Universals, the elec pump is in front of the racor, so the pump primes the entire system when bleeding from the engine spin-on filter. This is why the bleeding process takes a minute or so. Previous versions had the pump behind the Racor, requiring priming.

This is just what I've observed in documentation and my own setup, not diverse Universal Diesel engine experience.
 
Jan 6, 2010
1,520
Skip,

I liked your description for you filter changeouts & lessons learned, very detailed. Isn't it great when a plan comes together? I believe that if you work smart, you don't work hard. You first did your due diligence, came up with a great plan & executed it with nary a problem. A lot of folks focus on the end result (like wearing horse blinders), & that's when unforeseen problems arise.

I had the older primary model Racor fuel/water bowl separator (with the slip-in canister fuel cell) which was a messier job when changing. When I switched to the new Racor spin-on filter, it made filter changeouts a breeze. It's very rare that I need to bleed off water.

My C30 originally did not have an inline shutoff valve, so I put one in. Yea, the first thing is to shut off the valve so there is no self-leveling of fuel in the lines when you loosen the filters thus, allowing air in.

Some tricks I use are to first ball up paper towels & place them under the filters. I then remove the primary first. Before I install a new filter, I pour the fuel from the old filter into a plastic cup. If the fuel is clean I use this to fill up the new filter then install it. If the old fuel has particulates in it, I keep a small Gatorade bottle (with clean fuel) to fill the new filters. Then on to the secondary filter using the same method.

My 3M20A is a breeze when priming, it has a one bleed screw for the injectors. I used to manually bleed this screw & at the same time soaking up the spitting out of air & fuel. Not anymore. Other models may require bleeding as you go down the fuel system & injector bleeding so, some may need to be bled manually.

So, when all is buttoned up, I crack open the shutoff valve, hit my elec. fuel pump until the clicking stops (10-15 seconds). I bump the throttle up ever so slightly & start the engine. Never throttle up if the engine is running rough while still moving air thru the injectors, it will stall. It may stall the first couple of times, but you can tell it improves each time. If it stalls, I start the process over again.

It's never taken more than 3 tries to start-n-run. I then run the engine for 10 minutes. At about 5 minutes in, I start working the throttle at different RPM's just to make sure I don't have any air pockets. Lastly, I set it at 2200 RPM & run her for a few minutes until I hear no more air burps. Hopefully, may all your filter changes be clean & easy pal.

CR
 
Feb 26, 2004
23,352
Catalina 34 224 Maple Bay, BC, Canada
On mine and I think the newer Universals, the elec pump is in front of the racor, so the pump primes the entire system when bleeding from the engine spin-on filter. This is why the bleeding process takes a minute or so. Previous versions had the pump behind the Racor, requiring priming.
Fuel Pump Hose

Factory went: tank, pump, primary (Racor), engine

Should be: tank, primary, pump, engine

The pump will work in either position. The reason to put the Racor FIRST is that there is a tiny filter in the bottom of the pump. You want the Racor to filter BEFORE the pump.
 
Jan 6, 2010
1,520
Stu,

My system is setup first to primary filter, then the secondary, then to pump suction & then to discharge to the injectors.

Sounds like maybe another GM recall....Ha Ha!

CR
 
Feb 26, 2004
23,352
Catalina 34 224 Maple Bay, BC, Canada
The bleed bolt at the injector pump did not bleed any air. Fuel escaped immediately following breaking the bolt loose.
On our M25, the ONLY thing that needs to be done is to open the KNURLED KNOB at the injectors. NO BOLTS need to be loosened. Don't know if you have the same arrangement, just trying to clarify.
 
Feb 26, 2004
23,352
Catalina 34 224 Maple Bay, BC, Canada
Stu,

My system is setup first to primary filter, then the secondary, then to pump suction & then to discharge to the injectors.

Sounds like maybe another GM recall....Ha Ha!

CR
Actually, you're right. The factory got it wrong on ours and thousands of other boats.
 
Jan 6, 2010
1,520
Stu,

Good pickup pal, sometimes luck beats logic (or what the manual suggests). I have an industrial piping background, and the manual setup when I repowered didn't make sense at all to me either.

We learn as we go I guess. But, this type of filtering is NOT acceptable in the industrial/petro-chem/pharmaceutical industry. So I modified it to work properly. Double filtration before the pump is the way to go.

CR
 
Jan 6, 2010
1,520
Stu,

As an additive & for additional info, I mentioned my pal's 30 foot Newport just purchased (within the last 2 years that I assisted in bringing back home) had a 2 micron filter as the primary & a 10 micron filter as the secondary(REALLY?). He did state that the manual called for this alas, I never had the opportunity to read his manual. I can however say that when he had the mechanic add the new exhaust head & oil/fuel changeouts, that was how the filters were installed, 2 than 10 micron.

What surprised me, was that after talking with the mechanic (and, he came across as a very knowledgeable guy), admitted that he followed what he thought was the correct combination looking at the filter micron setup 2-then 10 & assumed it was based on the manufacturer's recommendations. Never having the manual to view, he pulled the filters & replaced in unison. "Sometimes however, the blind simply follow the blind."

Why would you want a 2 micron first & than a 10 micron secondly? So, let's follow the fuel flow from the tank. OK, it's dirty, it has particulates, so lets clog the smaller 2 micron filter first. If it's 2 micron, how then can it pass 10 microns to the secondary before this filter clogs? The mesh filter in the fuel pump is I believe less than 2 microns. Therefore with this configuration, the primary WILL clog up FIRST, thus killing the flow/the engine stalls & all at always the worst possible moment.

My pal has since changed his fuel filters to 10 microns first than 2 microns. This will retard the clogging of the mesh filter @ the pump delaying any stalling. He hasn't had a stalling problem in two years now (of which he had twice the first year partially due to old fuel & tank sludge buildup.

And, we have to contend with a very strong current coming & going & a narrow spit to transverse our pass. That's the time when an engine has a propensity to stall when fuel is starved. I just don't want to knock down another bascule bridge.

CR
 
Oct 9, 2008
1,742
Bristol 29.9 Dana Point
Fuel Pump Hose


Factory went: tank, pump, primary (Racor), engine

Should be: tank, primary, pump, engine

The pump will work in either position. The reason to put the Racor FIRST is that there is a tiny filter in the bottom of the pump. You want the Racor to filter BEFORE the pump.
I'm so glad I started this topic. I'm learning more every minute. Mostly that I'm blind. After further investigation, the fuel DOES go through the Racor 1st. It just looked like it went to the pump 1st, because the pump is aft of the racor about 10 inches, and at a glance it looks like the hoses are inline. But when tracing the routes, it is tank, Racor, pump, spin on.

I'm wondering now how it primed itself so well with only bleeding at the spin-on. the tank is full, so might have had some gravity to the Racor. The top of the tank sits about 6 inches above the Racor fuel inlet, and the hose is pretty much a straight shot.
 
Oct 9, 2008
1,742
Bristol 29.9 Dana Point
On our M25, the ONLY thing that needs to be done is to open the KNURLED KNOB at the injectors. NO BOLTS need to be loosened. Don't know if you have the same arrangement, just trying to clarify.
I had looked for the knob. Mine turned out to be a bolt. Wish I had the knob.
 
Feb 26, 2004
23,352
Catalina 34 224 Maple Bay, BC, Canada
I see. I just didn't want to confuse people by thinking they needed to loosen a bolt. It sounds, if I understand correctly, that you simply have bolt head where the knob is.
 
Last edited:

weinie

.
Sep 6, 2010
1,297
Jeanneau 349 port washington, ny
Hmmmm....another missing "knurled knob". The disease is spreading!
 
Jan 27, 2008
3,092
ODay 35 Beaufort, NC
Stu,

The mesh filter in the fuel pump is I believe less than 2 microns.
CR
The filter in the fuel pump will be a lot larger than 2 microns. It is probably more like 70 microns. A micron is a micrometer, about .000039 inches. So two microns is about .000078 inches. A human hair is about .003 inches in diameter for comparison.

Filtration is not necessarily absolute. A 2 micron filter will pass some percentage of larger particles. RichH is our resident filtration expert and a lot more knowledgeable on the subject than I am. Send him a PM if any questions, I'm sure he'll be glad to assist. Here's a link to a really informative article from Parker (Racor). Note they do not ever recommend a 2 micron filter unless a primary filter is used first of 10 microns or so upstream.
http://www.parker.com/literature/Racor/Mobile_The_Micron_Rating.pdf