So I ordered a few of these filter units to have on hand for projects like this since they were stupid-cheap (calling in it was $30 each with filters). The flip side now is there's no documentation anywhere to be found on them, including the USA distributor, who says the identical item was once sold as an OEM CAV filter unit...but CAV has long since given it up, and there's no trace of tech docs. They shrug their shoulders and say that the tractor guys must just drop them in place and make the same connections as they had before, and go on their way. In my case, I'm custom-installing, so I wanted info to verify the flow paths within. In a nutshell: were these designed for some reason to filter in parallel, not series? I'd assumed they were engineered to run as two filters in series when I saw the online front view, but on close examination once I had them in hand, it's clear they are NOT - the passages and the arrows on the four ports show that 1) the filters are plumbed in parallel, and 2) the ports are labeled as if intended for TWO inlets and TWO outlets (ports numbered 1-4, two in-arrows, two out-arrows.) Photos illustrate: Even with the addition of an external crossover hose to join one outlet with the opposite side's inlet, the outlet/clean fuel would still be /shared/ (it flows through one long passage that joins both filters) so it still wouldn't operate as a "series" setup. Any Ford tractor owners out there recognize these? Some reason they'd drop in to a Ford tractor and all of this would make sense? Wouldn't it be best to have the two filters work in series instead? Notice there's only one glass bowl, and that's the only drainable fitting, too. I'm thinking I want to be able to drain both sides, whether parallel or series, so I will probably add a drain to the aluminum-bowl side, too. Especially if they were left as is (run in parallel) there seems to be no reason the aluminum-bowl side wouldn't pick up as much coalesced water as the glass side would. Anyone got more insight into the design intent of this configuration? Thanks - Dave
AFAIK the idea of these filters is that you can have inlet and outlet on the same side or different sides to suit the installation you want. Although there are 2 connections for each only one is ever used. The fuel comes in on one of the top two ports with the "IN" arrows in your photo above, the other port is plugged. You take the fuel outlet from whichever of the ports marked with "OUT" arrows suits your particular installation. The IN & OUT ports can be on the same end or on different ends of the housing, it makes no difference, but there will only ever be one of each. What is critical though is that the clear bowl for water/sediment drainage MUST be on whichever side of the filter housing to which you connect your fuel inlet line, because that's the one that will collect the water & crap. So if for example your fuel inlet was on the LH side of your top photo you would need to swap the clear bowl from the RH side to the LH.
Don't try to overthink things like this. These date from the times of the prince of darkness, before even constant-pump-bleed-off had been thought of. The flow through them was s-l-o-w giving plenty of time for water to drop out in the first filter. The cleanliness requirements of the fuel were also not nearly as stringent as they are today.
You are correct on the "fuel flow".. the CAV was designed to run at 1-3psi. Basicaly "gravity feed"..
I don't have to try, it comes naturally. (actually it's somewhat genetic, reinforced by primary & high-schools as well as engineering school, so I'm in it for the duration, I'm afraid) Wait, that'd be Joseph Lucas, the Prince of Darkness? Or the Prince-of-Darkness prince-of-darkness? (I thought that guy was still around.) Seriously, though, I'm gonna have to read up on this, because the oldest Diesels I've been messing with are from the 90s, so from my limited window I'd assumed IPs had always been engineered so as to bleed off air/excess fuel. But unless there's something inherently crappy about the cartridge filter-element materials used for these units, would they not perform at least as well as a more modern filter (all concerns about dwell-time aside, since that's another issue)? I've already installed one of these units, custom bracket, even re-passaged so as to work as two filters in series, on my "project" CAT307 SSR - so now I want to know if that's been a mistake. Plan was to get a "see the water before it goes into the IP" glass drain-bowl, an expanded filter surface area, and cheap easy-to-find elements, that in my case would be roughly twice the size of the dinky little original. I even added inlet/outlet pressure gauges so I can get a sense of when it's blocking up. I hope that plan wasn't all built on a filter system that's for some reason basically incapable. The apple-sized original spin-on filter seemed utterly unremarkable; it gave no opportunity to drain/check water, and they were at least $20 a pop, so it was an invitation to the kind of clogging/water-in-IP issues that apparently killed my IP recently - you might remember that epic - which is actually ongoing as time and weather permit my return from the long rabbit-hole... --Dave
TBH regarding your excavator the first place as a water drain I would be looking at is the fuel tank. Does it have a drain at the bottom that is fitted with some type of valve or tap..? If the answer is no then get one in there PDQ (maybe do a bit of fabrication include a drainage bowl in the bottom of the tank to collect the water if it doesn't already have one) and start by draining the tank daily. If that's not producing measureable amounts of water then do it every 2 days. Keep increasing the time in between draining until you're getting something like half a cupful of gunk out of the tank before you see clean diesel. ALWAYS drain the water & sediment before starting if the machine has been standing for any period longer than overnight. I would say you might be lucky if the micron-rating of the CAV filters is anything less than 15 microns. Your OEM Cat filter is probably somewhere in the 2-5 micron range depending on the Part Number.
Thanks, Nige. I just went on a brief & fruitless excursion looking for some micron ratings so as to compare the CAV cartridge options with my stock filter setup. Apparently you need to file a Freedom of Information Act request to pry this info out of manufacturers, perhaps because they don't want to get caught up in standardizing & misunderstanding/misuse of their numbers. But while discussing this and other filter options, one web-retailer who has been in the filter biz for a long time cited 20-30 microns as being the absolute rating for a standard Cummins filter, FS1242B (also designed as a drain-bowl type installation) and said they're used on much higher-pressure systems than mine, so they're actually likely overkill for my needs. That's much coarser than I'd have expected. Any experience getting published ratings for filters such as those I'm trying to match or improve on? Point taken on the tank draining - yes, it's actually set up for that and I wasn't paying nearly the attention to draining as I should have - so now I'm swinging in the overkill direction... --Dave
There's a lot to be said for actually doing the maintenance recommended by the manufacturer in the way they suggest and at the intervals they suggest as a good starting point. On a "2 filter" (primary & secondary elements) system the primary fuel filter/water separator element would likely be something in the 15-30 micron range. Remember that water particles are much large than diesel fuel. The secondary filter element would be rated at 2-5 microns depending what EPA Emissions TIER the engine meets.
A quick check on Donaldson's cross ref website gives part number P556245 with the figure of 14 micron mentioned. https://dynamic.donaldson.com/WebStore/search/cross_reference.html Try plugging your oem filter number in there and see if you can get a micron figure. I'll bet it is in the range that Nige suggested. And yes, I was talking about uncle Joe Lucas. The inline Lucas/Cav/Simms pumps had no constant bleed off. If you ran one out of fuel there was no way it would start again without breaking out the spanners and bleeding it. Combined with crappy batteries and dynamo charging systems it made for a nice little earner for field service.
Cmark: Thanks for the history - good stuff. I can only imagine the fear and loathing of driving a near-E tank gauge - or a non-working one. I'd go nuts thinking I was hearing my idle dipping down... Thanks for the Donaldson link - that's exactly what I had NOT found before... Plugging my CAT's OEM fuel filter (Wix 33399) into it, bottom line seems to be "Efficiency 99%: 30 Micron". (Can I just use window-screen, then?) I repeated your check of a cartridge that's compatible with my newly-installed twin-head filter unit (not sure they're all the same rating). I used Fleetguard's FF167 to search, and (drum roll) Donaldson's cross (P556245, as you found) gives me "Efficiency 99%: 14 Micron." So if we believe the data from Donaldson and I can source their cartridges, I should be more than good to go with my new setup...right? I'm thinking if I really were paranoid I could keep the 30u stock filter in place as a last line of defense, and in theory it would never plug, but really, I'd rather not add another item to have leaks/problems with if possible. Donaldson link also gives a no-efficiency-rated version of the same filter that's obviously not built the same (no easily-seen holes in top or bottom) - P502420 - but no others. Nige, do you find this compelling, or is there something that's still going to foil my little scheme?
I have to agree. Using serial prefix 2PM which should be pretty close to your machine, gives cat part number 094-7073 for the fuel filter which goes to Donaldson P550048 which indeed shows 30 micron. I must say I am surprised at this.
Cmark, Yes, I should have verified my old work in coming up with that Wix cross-reference. I've got two p/ns from the Japanese parts book; one is what you got, the other 094-7070, which is Google-resistant at my level, but comes up as a CAT filter. Might that be much different in micron rating? Thanks - Dave
094-7070 is the filter assembly, ie. 094-7073 complete with the filter head.
Donaldson makes a nice spin on filter adaptor for those cartridge bases, I bought and used them on 4.236 Perkins motors we had in paving equip. The filters have plastic bowls so you can see any water in them.
Try going to the RACOR site.. the sales pamphlets that I have at work give flow/gals and micron ratings.. Then you can cross THIER # to something more $ friendly... for THAT exact set-up you want to use, I use Volvo Filters.. sorry, forgot the micron size.. I just cross it from CAV to Volvo.. Small enough to do the job but not small enough to clog the element every time you run the engine..
Thanks TPG - good tip, but I am already expecting a lifetime supply of Donaldson filters to arrive soon, so I don't want to look at RACOR (and find that there's a better option...) (BTW this is for the same machine for which I finally had that IP rebuilt a few months ago - which still hasn't seen the first bit of new fuel through it, while I grub around in the weeds finding more problems to fix...and more weeds...) --Dave
I've now got about 20 minutes of run time on this dual CAV-style filter head now, and it has had a persistent leak at the square-cut gasket above the glass bowl side. I tightened it as much as I dared, but it kept weeping. Took it off two or three times, wiped it down, then replaced that filter-element because it looked like the paint was failing/rusting at the seal. With the new filter, I installed new gaskets, and got the same old leak back. While tightening to try to stop the leak, apparently too much, the plastic bottom nut popped loose, letting the filter & bowl drop out - but with no apparent damage to anything, since I had a rag below the glass bowl. With no great options, I tried again, and didn't tighten quite as much. I started the machine, and it was spraying out the bottom gasket, worse this time. Drained it down, tried re-seating the gasket by twisting the bowl with some tension on the bolt, then retightened. This time, I primer-pumped to get up to operating pressure, saw the same leak just starting up, and almost immediately was rewarded with a loud POP, as the plastic nut again yielded and let the glass bowl go again. But this time, the bowl was broken into four+ pieces. I had to cannibalize an aluminum bowl from a shelf-stock filter assembly to get by for now...not happy. What's the typical operating pressure of these bowl/filter setups? Is there any such thing as maximum tightening torque for the glass bowl nut? Any tricks to getting them to seal, or should it be "plug-and-play?"
I think as someone mentioned earlier they're made basically for gravity feed or suction side use, as always YMMV.
Do you know that the top and bottom seals look the same but are slightly different sizes? Bigger one to the top.
Yeah, I noticed that - I woulda had to stretch the wrong seal in place above, and not sure I coulda gotten the larger one in place on the bowl below. At one point with the engine running, pressure-gauge at entry was around 32psi (from mech pump) and the drip was slow, like a drop every thirty seconds. Maybe I should have ignored it... I'm thinking there might have been a defect in the edge of the glass bowl that I couldn't/didn't see, because the leak seemed to always be from one point, but different rotation of glass moved the leak, so to speak. Seller of these units was blowing them out cheap for some reason, and perhaps now I know why.
CAV systems as I recall were all rotary (Roosamaster) and used diaphragm pumps.. probably 7-8 psi? Not trying to burst your bubble but I think you may just have a lot more pressure than they were designed to handle.
Can you not run the filter on the supply side? Hook the fuel supply line from the tank to the filter inlet and connect the pump inlet to the outlet side of the filter. Either way it needs to seal.
Yes, could do, but it's an invitation to air being sucked into the system as a replacement for the pesky leak. I've not run it enough with two aluminum bowls to know whether the leak is no longer a problem, but if that proves out, I think there's no reason I shouldn't be able to swap another glass bowl back in to replace the temporary aluminum version. (After epic delays and IP-rebuilding cost that stemmed from fuel-quality problems, I am not willing to live without a 'window' into the fuel again). Tx - Dave