Instructions on changing hydraulic filters on Cummins ISL 400

[Jay Sigel]

I have a hydraulic driven cooling fan in a 2006 Travel Supreme motorhome with a Cummins 400 ISL engine. This month it is 3 yrs old and has about 28,000 highway miles on it. There are no service manuals on replacing the hydraulic fluid and filters and the only information is written on the reservoir, which states the fluid type. There are supposed to be 2 hydraulic filters, a spin-on external filter (which is mounted under the reservoir) and an internal one. While changing the external one should be rather straight forward, any suggestions on accessing, draining any fluid and replacing the internal one in the reservoir would be welcome. How much AW46 fluid should I have on hand for this job? I'm thinking a couple of gallons should do it judging by the size of the reservoir. There is a pressure gauge on the filter that does not yet indicate that it should be replaced. Should I wait until it says to replace it? Thanks, in advance, for the advice!

[Jay Sigel]

I have a hydraulic driven cooling fan in a 2006 Travel Supreme motorhome with a Cummins 400 ISL engine. This month it is 3 yrs old and has about 28,000 highway miles on it. There are no service manuals on replacing the hydraulic fluid and filters and the only information is written on the reservoir, which states the fluid type. There are supposed to be 2 hydraulic filters, a spin-on external filter (which is mounted under the reservoir) and an internal one. While changing the external one should be rather straight forward, any suggestions on accessing, draining any fluid and replacing the internal one in the reservoir would be welcome. How much AW46 fluid should I have on hand for this job? I'm thinking a couple of gallons should do it judging by the size of the reservoir. There is a pressure gauge on the filter that does not yet indicate that it should be replaced. Should I wait until it says to replace it? Thanks, in advance, for the advice!

[quikduk]

I can only tell you relative to the hydraulic filter on my diesel tractor.

I change the filter with every fluid change. This typically occurs at every 100 hours which is equal to 10,000 miles.

You should be able to remove the internal filter through the top of the reservoir but you need to verify this. You should also have some way to turn off the flow for when you change on the spin on one below to minimize the mess. If you do, remember to turn the valve back on, much like a coolant DCA filter.

I have never seen any type of gauge to tell you when to change it. It is based typ. on mileage or hours of use.

Of course, YMMV...but let us know.

[AFChap]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">gauge to tell you when to change it. </div></BLOCKQUOTE>
My '03 Cummins ISC has a gauge on the hydraulic filter also ...in addition to the needle indicator, it has green, yellow and red areas. Service places have told me not to worry about it as long as the gauge is in the green, but I changed it at least once (maybe twice) in 5 yr/45k miles.

[Norm Payne]

If you have a Spartan chassis give them a call. They can give you the part numbers of the filters and the amount of fluid needed. They should also be able to explain how to change the fluid and filters.

[Jay W]

Jay on my 05 Spartan Chassis the tank held a little over 2 gallons of AW 46.

I placed a pan under my external spin on filter that is located in its own compartment.
The external filter removal also drained the tank completely.

The filter inside the tank is removed by by a Wing nut securing the filter to the bottom of the tank. It is marked top or up.

That is how mine went yours maybe different.

[Jay Sigel]

Thanks. And, I found the AW46 at Sam's Club yesterday. They come in 5 gallon pails and were located near the Rotella.

[bcbounders]

Do many people on here perform their own hydraulic system maintenance? If so... how easy is it to change the spin-on filter? Sounds like a mess... that once the filter is removed, the hydraulic fluid starts a-flowin'!

Can you just "act fast" and spin the old one off and the new one back on before you lose too much?

[Jay Sigel]

I finally did it all yesterday afternoon. I will graphically explain the procedures. But, you will be using your arm and chest muscles to pump the fluids out. Get someone else to do this if you have heart disease! (I am an ER physician.)

First, I drained the transmission fluid and then the hydraulic fluid. I know this posting is about the hydraulic fluid, but it makes sense to do both at the same setting. I have a 3000MH Allison transmission, in case that matters.

The hydraulic reservoir has a dip stick and not a view glass. The hydraulic reservoir lid is held on by a ring of 2 linked kind-of C-clamps with each half linked by a 9/16" bolt. It reminds me of a pressure cooker.

Because it is messy, you will need the following items: Old jeans, a long sleeve shirt and old shoes; a basin to catch the fluids (4.5 gallons for transmission, 2 gallons for hydraulic fluid); a roll of paper towels; empty Rotella gallon containers for holding the waste oil; standard spin-on filter wrench; 9/16" wrench (a ratchet ring wrench worked nicely); filters (internal: 97610A "Nelson power steering reservoir" cartridge; external: spin-on Zinga ZAE10 "Stauff SF-6505") both obtained from Spartan; 2 gallons of AW-46 fluid (I obtained a 5 gallon pail from Sam's club in the aisle with Rotella, etc.); a "multi-use" hand pump (Shop Craft 36667, purchased at an Ace hardware store) - you absolutely need this; 8-12" rod or wood dowel or paint mixer stick and 2 cable ties to keep the plastic hose on the intake end of the hand pump from coiling; a black marker pen.

If you also do your transmission fluid change, you will also need: more waste containers; a 5 gallon pail of Trans Synd fluid (obtain from your regional Stewart & Stevenson) and I highly recommend getting 2 more gallons of that in 1 gallon containers; 3/8" ratchet wrench; 15mm 3/8" socket; torque wrench with adapter to fit the 3/8" socket since most torque wrenches are 1/2" drives; filter kit (2 identical filters cartridges come in each kit, one for lube the other for main filters, plus a set of gaskets and o-rings - obtain these from Stewart & Stevenson); putty knife; a standard screw driver.

Hydraulic drainage procedure: Place the waste basin under the spin-on filter and loosen it with the filter wrench. The fluid is thin and when you loosen the filter, the reservoir drains out quickly and completely. Stand back! Now, totally remove the filter and put it in the waste basin. Remove one of the 9/16" bolts on the reservoir lid retainer clamps and the loosen the other so that you can remove or slide down the clamp. Remove the lid. Placing your hand inside the reservoir, you can feel the wing nut holding the internal filter on. There's a spring under the wing nut so remove the wing nut carefully and don't lose the spring. There is a cone-shaped retainer under the spring, which pulls up. Grab the filter and place it in the waste basin. It will have a black gasket on each end and the new filter should have new ones. Reinstall the new internal filter in the opposite order. Install the new spin-on filter. Using the hand pump, put a few ounces of hydraulic fluid in an empty Rotella gallon oil container and rinse it out. Then fill it up to the 1 gallon mark on the side of the Rotella container. Pour it inside the reservoir container. Refill the gallon container and pour the 2nd gallon into the reservoir. It should be about 2 inches from the top. Place the cover on the reservoir and check the dip stick. Adjust the fluid level to the full cold line. Reinstall the lid clamps when the fluid level is correct. Make sure the dip stick is on tightly. Clean up any spills. Poor the basin oil into waste containers for transporting to an oil recycling establishment. Write the mileage down in your maintenance log. Using the black marker, write on the side of the AW-46 pail that you have 3 gallons left (the pail was white).

Allison transmission drainage procedure: I actually did this before the hydraulic fluid and the hydraulic fluid change is much easier. Run the engine a few minutes in neutral until the temperature is about 90 degrees. Turn off the engine and extend the rear hydraulic jacks so the you can easily get under the transmission and work. Bring several sheets of paper towels with you. The drain plug is towards the front of the vehicle on the underside of the transmission case, opposite the lube filter and is a 3/8" socket plug. A 3/8" ratchet wrench easily fits inside it. Expect about 4.5 gallons of fluid to drain. Loosen the plug enough to be finger loose and then remove it with your fingers while the basin is just underneath. Wipe any sludge off the inside of the plug and place the plug on a clean paper towel. Using a 15mm socket wrench, remove the five of the six bolts holding the lube filter (I did the lube filter since it was farther away from me crawling under the driver side, but which filter you do first doesn't matter), leaving the sixth bolt closest to you very loose. These bolts are torqued on and you might need a breaker bar to loosen them. Don't forget the "right hand rule" and make sure you are loosening and not tightening the bolts! Put the bolts on the paper towel. About a pint of transmission fluid will drain out when each filter is removed, so position the basin to catch that. You will probably need to gently pry the filter cover off with the flat screw driver. When the fluid drainage slows, remove the last bolt with your fingers and drop the filter-cover module straight down. Place the cover and filter on a work surface. The filter pulls off the cover. There are three gaskets: a flat one that is partially stuck to the cover, a large black o-ring that is inside the flat gasket and a smaller brown o-ring on the side of the filter mount. The double filter kit also has a new o-ring for the drain plug (the old one looked fine so I didn't change it). Pull off the old o-rings using the screw driver or putty knife to get under them. Pull off the flat gasket and use the putty knife to carefully remove any adherent gasket material. Avoid marring the surface. Do not use steel wool, sand paper or anything with abrasives to clean the gasket material off the base. Using a clean paper towel, wipe off the filter side of the cover including the o-ring grooves and bolt holes. Place the flat gasket on the base. It is not reversible and the writing side is down. Make sure it lines up with all of the holes. Place the 2 o-rings on. Push the new filter on - it will be snug. Look at the under side of the filter vase. Notice the single bar. The bars on the main and lube filters face each other parallel. Crawl back under the vehicle and place the filter-cover module back up there with the bars facing each other. Place each bolt back in finger tight. Using the 15mm socket wrench, tighten the 6 bolts trying going from one side to the opposite side. Next, torque the bolts to 38 or slightly higher foot-pounds. This is pretty tight. Again, torque opposite sides. Repeat the procedure for the other filter. Replace the drain plug; it wasn't real tight. You are now ready to put the transmission fluid back. How much fluid will you need? That's easy. Take your waste transmission fluid and poor it into the empty gallon Rotella oil containers. I filled up about 4 of these. Remove the transmission fluid dip stick and put it somewhere clean and safe. Put a gallon container of Trans Synd transmission fluid on the engine frame near the dip stick tube, positioning it so that you can see the fluid line on the side of the container. In my vehicle, it fit next to the alternator. Using the hand pump, insert the intake hose into the Trans Synd and the discharge into the dip stick tube and pump out the gallon. You will need to refill the gallon container from the Trans Synd pail. Yes, you could pump the fluid out from the pail, but then you wouldn't know how much you put in. I put in about 4.5 gallons. Put the dip stick back in and start the engine. With the brakes on (of course) shift the transmission to drive, then neutral, then reverse and neutral, several times. With the engine running and the transmission in neutral, I checked the dip stick and it was perfect. I pumped out the remaining Trans Synd from the pail into one of the Trans Synd gallon containers until the I was just pumping air. I poured the remaining fluid from the pail into the gallon container without spilling much. I started off with 1.5 gallons of Trans Synd in the gallon containers plus the 5 gallon pail and ended up with almost 2 gallons total. It's a good idea to have some extra in case you spill some (and you will). Put the extra gallon container(s) of fluid in your compartment where you keep your spare oil, etc. Clean up and you are done!

[bcbounders]

Jay,

WOW! Thanks for such a detailed posting! I'm still reading through it all, absorbing all of it, to determine if I'm going to "brave" doing this myself, or just let "the professionals" handle it, so I can stay clean!

Really appreciate you taking the time to post all of this!