[Rich]

This post contains a summary of the pertinent details from a rather lengthy thread I posted quite a while back that I have condensed here.


Why I did it: A few years ago I noticed that the radiator was partially obstructed with grey sludge. The sludge was visible from the radiator fill opening with the coolant drained down to uncover the top of the core.

Extensive flushing with garden hose and treatment with Prestone radiator cleaner was not at all effective in removing the sludge. So, I removed the radiator and took it to a radiator shop and had it flushed with a very high volume radiator flushing setup. They hooked it up and a massive amount of water came gushing out, soaking the hapless hired help who must have been low man on the totem pole. This flush removed all visible sludge from the radiator.

A year or so later I subsequently noticed more sludge in the radiator. So I then decided to install a filter to mitigate the problem. At some point in time I will replace my radiator, and want to ensure, to the best of my ability, that I can prevent the new radiator from becoming clogged.

The filter I installed is a bypass coolant filter normally installed in big rig diesel trucks that pull semi trailers.


How it works: The coolant feed to the heater cores is cut into with a tee fitting in order to supply coolant into the filter. The filter outflow is in turned tee'ed into the heater core return to the water pump. Thus, a portion of coolant flow to the heater cores bypasses the heater and flows through the coolant filter instead. This is why it is called a bypass filter. It must be installed in this manner, in parallel with the heater cores, not in series.

The filter is similar to a large oil filter. It contains a large pleated paper element that does the actual filtering. The filter is specifically manufactured for use as a coolant filter.


How it installs: The installation is very straight forward. It can be installed without making any permanent modifications to the truck. It is only necessary to remove two 90 degree bend hoses and replace them with new straight hoses and brass tee fittings. The rest is to just mount the filter, and that can be done using only existing threaded holes in the firewall. I did drill one additional hole in the firewall for a fourth bolt for the filter mount plate, this was optional, not necessary, and I would likely not do so again were I to repeat the installation.


Results: Over the course of several years the amount of visible sludge in the radiator has been substantially reduced. I have removed and cut open several filters and captured a portion of the junk that was filtered out.



Below is a picture of the mounted filter. The coolant feed flows in through the hose leading to the top of the filter mount. The coolant return flow is through the hose on the right that is encased in the silver heat shield sleeve. The return hose connects to a brass tee that replaces the stock 90 degree hose. The shutoff valves with yellow handles minimize loss of coolant when changing the filter.





Below is a picture of the feed to the filter. The brass tee replaces the stock 90 degree hose.





Below is a picture of the filter mounting plate. It is made from aluminum plate. Note: Unseen behind the plate are spacers behind the top two bolts and the the lower left bolt. Except for lower left, existing threaded holes in the firewall are used to mount the plate.





Below is picture of some of the crud removed by the filter. On the left is material that appears to be sand. On the right is material that appears to be a finely powered clay.





Here is a list of the parts I used:

The mounting plate I made myself. Used 12" x 6" x .375” aluminum. I used aluminum as opposed to steel in order to make it easier to cut and shape with my equipment and to save some weight. I also made spacers that are located behind the plate at three of the bolts holes. The spacers are .7" in diameter; which I turned down from .75 inch diameter aluminum rod and drilled for the mounting bolts. The aluminum I ordered from www.metalexpress.net.

The 4 plate mounting bolts I used are 8mm x 1.25 x 50mm.

I Used 2 10mm x 1.25 x 30mm bolts to mount the filter head to the plate. I threaded the plate for these bolts. You will need longer bolts if you wish to through bolt using nuts.

Baldwin Filter Head, part number CFB5000 - This is the filter head only. It does not include the plugs, valves, or hose barbs. www.baldwinfilters.com

Baldwin Coolant Filter, part number B5134 - This filter contains no SCAs (supplemental coolant additives). I believe only wet sleeved diesel engines routinely require SCAs be added to the coolant by the operator. I will omit the long explanation. But be aware most coolant filters include SCAs inside as most coolant filters are installed on diesel engines that require the addition of SCAs. Adding too much SCAs will cause problems. If the shop does not stock these filters, then you may need to buy a case of 12. That is is minimum order from Baldwin. I purchased the filter head and filters from a local Peterbilt service center.

All brass fittings are manufactured by Parker http://www.parker.com/ead/cm1.asp?cmid=396

Quantity 2 of 3/8” male NPT Countersunk Hex-Head Plug, Parker part number 219P-6 for plugging unused ports in filter head.

Quantity 2 of 3/8” male NPT x 3/8 female NPT mini ball valve, Parker part number MV608-6. Shutoff valves eliminate coolant from draining from the lines when changing filters. These are very cool.

Quantity 1 of 3/8” male NPT x ½” beaded hose barb, Parker part number 68HB-8-6, for the filter outlet.

Quantity 4 of 3/8” male NPT x 5/8” beaded hose barb, parker part number 68HB-10-6, 1 is for filter inlet, other 3 are for constructing tee connection to heater hose.

Quantity 1 of 3/8" female NTP x 3/8” female NTP x 3/8" female NTP tee, Parker part number 2203P-6, used with 3 of the hose barbs listed above to construct a 5/8" barbed tee. The supply store did not stock a 5/8" tee, so I made one up from the 4 parts. Find a good brass 5/8" tee and save some money.

Quantity 1 of 180 degree bend pipe, Toyota part number 87248-60480. This connects one side of the inlet tee to the heater valve.

Quantity 1 ½” x ½” x ½” tee, part number unknown, came out of the supply stores odds and ends bin, for connecting the filter outlet to the existing heater outlet hose.

The 5/8" feed hose I used is Gates Green Stripe. Need 4 feet (will have just a little extra left over), Gates part number 28441.

The 1/2" outlet hose I used is Gates Safety Stripe. Need 2 feet (and will have extra left over). I would have used Green Stripe, which is a premium hose, but couldn’t find any local stocking suppliers. If any of you know of a supplier (by the foot) for 1/2" Gates green stripe hose please let me know.

I covered the 1/2 return hose with a thermal protective sleeve, as it passes above the exhaust header. Thermo Sleeve from Thermotec, part number 14010 - www.thermotec.com.

The hose clamps I used are manufactured by AWAB. These are premium 316 all stainless steel clamps including the screw being stainless. The serrations do not pierce the band, so they do not chew up the hose. I bought these from West Marine. Need 8 to fit 5/8" hose and 6 to fit 1/2" hose. These will never corrode and will never fail. West Marine pricing for these clamps is expensive, but one of their stores is close to me and thus is convenient. These are premium quality hose clamps that are very unlikely to ever fail.

[tucsonlx]

Wow, you actually filtered a quarter out of your system. Eventually you will pay for the mod. Actually that is a pretty clean install. I am impressed and if I find the time plan on doing it to mine. THanks for the write up

[Zane]

Rich,

How often do you change out your coolant filter? Every XXXX Miles??

[stayalert]

How di you get three piles of distinctly different materials? 3 dif. filters? dif. stages of the same filter...Just trying to understand....Good write -up thanks for sharing..

[Zane]

Rich,

Another question for you. I live in the mid west and our winters get a bit cold and I'm wondering how this has affected your heater output in the winter months due to the bypass filter? If you live in Arizona this may not be a concern to you, but I have no idea were you are from...

I guess if it did restrict your heater flow you could always shut the valves off at the feed to the filter and the return during the winter months.

What are your thoughts???

Zane

[1000-oaks]

What IS that grey sludge, anyway? I had a bunch in the bottom of the overflow bottle. I'm currently running a few cycles of fresh water though my system to try to get rid of all the old nasty grey/brown coolant, it's probably the original stuff. (Bought the rig with almost 100K miles on it, no idea how the PO's treated it.)

[RavenTai]

Originally Posted by stayalert

How di you get three piles of distinctly different materials? 3 dif. filters? dif. stages of the same filter...Just trying to understand....Good write -up thanks for sharing..

Originally Posted by Rich

Here is how I recovered the stuff from the filter. First I poured the coolant out of the filter into a 1 gallon zip lock bag. Then I cut open the filter, removed the paper and metal filter core, and rinsed the contents of the filter can into the ziplock bag.

Then I cut the paper pleat away from the metal core, and then washed the paper with water into another 1 gallon zip lock bag. When finished I combined contents into a single bag, and hung it up with one corner down. After a day all of the solids settled down into the low corner.

I twisted up and cut off the low corner. In the process of doing this the lightest materials floated up resuspending in the water. I transferred the water into another bag, let the remainder settle out over another day, drained most of the water out of the bag, and poured the bottom remainder through a coffee filter. This produced the small pile of light brown material. It is the portion of filtrate that is most easily suspended in the coolant and therefore is not likely to clog anything; it just goes with the flow.

The big pile contains a lot of different stuff. Much of it is dark and granular, like a fine sand. It also contains a substantial amount of very fine powder some of which is probably dried gray sludge. All mixed together dry, it is not possible to say what is dried sludge and what is not. I can say that the darkest, most sand like material readily settles out, when wet it is not sludgy, and not likely to clog the radiator. It is abrasive, and perhaps has an adverse effect on the life of the water pump. The dark granular material is definitely not the same grey stuff that collects in the top of the radiator.

Attached is another picture. This picture contains the same material from the previous picture, and in addition, contains a dried sample of grey sludge that I had previously flushed from the heater cores. The grey sludge when dry has a greenish tint and is in the upper right side of the picture.

The grey sludge I collected before installing the filter by directly hooking up a garden hose to the heater core outlets, and flushing full force, collecting the output in a 5 gallon bucket. The grey sludge settles out fairly quickly and dries to a very fine powder that is not at all granular.

At this point in time, all I can conclude is that there is a fair amount of "stuff'" in my coolant system that the filter has caught. The radiator still has a small amount of visible grey sludge, which is only visible inside a few of the core tubes, but there is less than when I installed the filter.

Since I don't know whether or not my engine is still producing grey sludge, I can't say one way or another if the filter is keeping the radiator from getting worse. I can only say the radiator is cleaner than before installing the filter and has not gotten worse.

Coolant Filter Install



I am in a similar process right now with what I got out of the overflow bottle, not doing quite as nice a job of it as Rich did,

ZJZ, the amount that flows through the bypass is very small and will have no effect on the heat,

the idea of a bypass filter weather it be coolant oil or ATF, is to make a small short circuit and filer a small amoount of fluid at a time so that it will not effect the rest fo the system , eventually all of the fluid will pass through and be purified, there is a about 1/8" orifice in the outlet of the filter that keeps flow rate down to a near trickle,

Originally Posted by 1000-oaks

What IS that grey sludge, anyway?

That is the $64,000 question,

possibilities:
casting sand and clay left over from the forming of the black, head and other cast parts in contact with the coolant that did not get cleaned out during manufacture,
Head gasket material from a deteriorating HG / solids precipitating in the coolant from blow by past a leaking HG
Solids precipitating out of the coolant from formerly dissolved coolant additives .
Byproduct particles of corrosion and/or electrolysis and/or galvanic corrosion of iron and aluminum parts in contact with coolant
Something else?

As far as I have read only thing that has been ruled out is funk resulting from mixing of coolant as it shows up in vehicles that have run Toyota red their entire life.

[Rich]

Raven did a pretty good job of answering questions posted - thanks. What follows is in part redundant to Raven's replies.

Originally Posted by tucsonlx

Wow, you actually filtered a quarter out of your system...

I was hoping for something more like gold doubloons!

Originally Posted by zjz4476

...How often do you change out your coolant filter? ...

In the big diesel semi trailer engines the same filters can be run 100,000 miles. In the course of 2 1/2 years (I'm not sure, maybe 25K miles total) I've changed it out I think three times just to be able to cut it open and see what's inside. From the amount of stuff I've seen collected so far I'm reasonably certain 60K mile changes would be ok, 100K may also be ok - don't really know. Certainly not worth changing anywhere near as frequent as a oil filter. Note, this is specific to my experience. If an engine where as heavily clogged as the picture posted by Christo, more frequent filter changes would no doubt be required. No additional harm would occur if the filter were to become clogged, it would just flow less and less coolant and filter less additional sludge. Since it is a bypass filter, this slowdown would have no other affect on the cooling system.

There is about 240 square inches of pleated filter area inside the filter, for whatever that is worth.

Originally Posted by stayalert

How did you get three piles of distinctly different materials?...

Raven's cut 'n paste of my older posting covered that in depth. The grey material came from a previous flushing, and the black and beige settled out a different rates when I washed out a used filter.

Something worth repeating is the pile of black material contains a lot of fine material hidden underneath the course material on top. And it is the fine material, and not the course material that clogs the radiator core. The fine material clings to the inside of the top of the tubes, and slowly accumulates and chokes off the tubes.

Originally Posted by zjz4476

...I live in the mid west and our winters get a bit cold and I'm wondering how this has affected your heater output in the winter months due to the bypass filter? If you live in Arizona this may not be a concern to you, but I have no idea were you are from...

Well, where I used to live I had the opportunity to snow camp at -20° F! Back then I was driving a FJ40. All I can say is that my FZJ80 with coolant filter is plenty warm, but it is extremely rare that I ever wear winter clothing where I now live on the west coast.

The flow into the filter is limited to passing through a single 5/32 inch diameter hole in the filter outlet. I don't expect that heater core flow is diminished by the coolant filter in a substantial way. But that is a good question. I did ponder the same while planning the install and came to the same conclusion as you, which is if I ever did not have enough heat, say to defrost windows, I would just close the filter inlet valve.

Originally Posted by 1000-oaks

What IS that grey sludge, anyway? I had a bunch in the bottom of the overflow bottle. I'm currently running a few cycles of fresh water though my system to try to get rid of all the old nasty grey/brown coolant, it's probably the original stuff...

Your guess is as good as mine. I do think the black stuff (btw, look closely, while primarily black there is a wide variation of colors in there) is mostly sand. The fine stuff on the right - I really don't know. Casting sand clay? That's as good a guess as any.

With respect to flushing sludge from inside radiator core tubes, my experience is that the volume of water available from a house hose bib via a garden hose is not sufficient to do much of anything. I flushed my engine for hours with a prestone flushing tee. Did a fine job of flushing coolant. Didn't do much of anything for clearing out the radiator core tubes.

However, disconnecting the inlets and outlets of the heater cores, and flushing each with a garden hose hooked up directly to the heater core outlets, one at a time, did flush out a significant amount of sludge from the heater cores. Given the much smaller size of the heater cores, the volume of water from a garden hose maintains much better velocity than trying the same with the radiator. I, and others, have previously posted on how to go about doing that. Short story is to disconnect the heater core inlet and outlet hoses on the firewall. Using barb to garden hose adapters (availabe at hardware stores), 1/2 inch for rear heater, and 5/8 inch for front heater, hook a garden hose to heater core outlet, hook another hose to heater core inlet to direct flush water out of engine comparment, and blast way.

Notice the metal tube that feeds the two heater core inlets on the firewall to the right of your cylinder head? See that it has a dead end hanging down? If you pull that pipe and flush it out you will likely find a collection of sludge sitting in there.

[stayalert]

perhaps I should have read all of the words in the post...I have more questions but will re-read what's already been posted to save myself the embarrassment...

[Rich]

Originally Posted by stayalert

perhaps I should have read all of the words in the post...I have more questions but will re-read what's already been posted to save myself the embarrassment...

I think perhaps you misinterpreted my response. I mentioned that Raven answered your question, which he did, after you asked. I wasn't implying that you asked a question that was already covered prior to you posting a question. No worries.

[Romer]

Nice write-up Rich. Added to the modifications section of the FAQ

[RavenTai]

Rich what year is your FZJ80?

[Rich]

It is a '97.

[psfpilot]

Originally posted by Rich
It must be installed in this manner, in parallel with the heater cores, not in series.

Is this due to the filter being too restrictive? If so, would it raise the upstream pressure too high, or would it just make the heater core less effective?

[Rich]

The filter can is designed for bypass use. The coolant outlet hole in the filter can is 5/32" in diameter, and it is this that restricts the flow. If it were installed in series with the heater it would greatly reduce the heater heat output.

[Rich]

In case anybody finds it interesting, I tested all of the filtrate samples pictured above with an extremely strong magnet I recently obtained. Each of the samples contained a small amount of slightly magnetic material.

Presumably a portion of each "stuff" contains iron block corrosion products.