How much oil?

tshort · Post by **tshort** » Mon Sep 11, 2006 9:01 pm

OK, basic question but I can't find the answer in any of the manuals ...

What is the capacity of the oil system - how much do I add after the oil change?

The engine seems happy at 5qts on the dipstick, but I don't know how much I should add back after changing the oil... ?

Thomas

Jr.CubBuilder · Post by **Jr.CubBuilder** » Mon Sep 11, 2006 10:14 pm

Eight quarts, or two gallons, it's in the TCDs if you need a reference.

N2865C · Post by **N2865C** » Mon Sep 11, 2006 11:11 pm

And more info in the Owners Manual re: maximum and minimum oil levels. Both the TCDS and the Owners Manual are available on the members only page.

Post by **GAHorn** » Tue Sep 12, 2006 3:14 am

tshort wrote:OK, basic question but I can't find the answer in any of the manuals ...

What is the capacity of the oil system - how much do I add after the oil change?

The engine seems happy at 5qts on the dipstick, but I don't know how much I should add back after changing the oil... ?

Thomas

The TCM Overhaul Manual for this engine specifies a max oil capacity of 8 quarts, and a minimum for operation of 4 quarts.

tshort · Post by **tshort** » Tue Sep 12, 2006 3:42 am

Thanks guys.
I looked thru the whole owner's manual today and couldn't find any capacity info. It is not in the parts manual for the C-145. I didn't think to look in the TCDS.

This is my first oil change on this plane, TT 58 hrs SMOH; oil was changed at 5 hours and at 25. Cut the filter, essentially no metal (a couple tiny microscopic grains but no else). Waiting on the oil analysis but looks good!

Am I correct that the oil filter adapter on the back of the engine replaces the oil screen? I glanced over it today and didn't see an obvious screen. Will pull that too if it is still there.

Thanks again.

Thomas

Post by **GAHorn** » Tue Sep 12, 2006 4:27 am

There are two screens, a smaller diameter suction screen which is best left alone, and the larger pressure screen which is replaced by the FM Enterprises oil filter adaptor.
While the suction screen is smaller diameter, it is also much coarser than the pressure screen. It does not normally need inspection/cleaning until overhaul. It's primary purpose is to prevent a dropped nut, washer, tool, oil can piece*, etc. from being picked up by the oil pump and damaging the pump gears.

*Remember when oil came in metal cans? We used a can opener or a specially fitted oil-funnel with a cutter on it to pierce the can's lid before pouring the oil into the engine. Sometimes large slivers of the metal can would be torn off and would be poured out with the oil. Some engine drain plugs had magnets on them to attract such metallic objects. Ahhh, the good ol' days! (Then they came out with those trashy cans that still had metal lids, but the sides were made of cardboard! Yeech! I've still got half a case of Mobil Red-Band straight mineral.)

cessna170bdriver · Post by **cessna170bdriver** » Tue Sep 12, 2006 4:44 am

tshort wrote:Am I correct that the oil filter adapter on the back of the engine replaces the oil screen? I glanced over it today and didn't see an obvious screen. Will pull that too if it is still there.

Thanks again.

Thomas

The oil filter replaces the "pressure" screen, a fine screen on the pressure side of the oil pump. On our C-145's and O-300's that screen is/was on the lower right corner of the accessory cover. Your TCM parts manual should give you a good idea of what it looked like.

There is also a "suction" screen on the lower left corner of the accessory cover. The suction screen is much smaller in diameter that the pressure screen, and is normally a coarse screen (unless a TCM service bulletin whose number I don't recall has been complied with, in which case it is a fine screen like the pressure screen). The purpose of the suction screen is to stop pieces large enough to damage the oil pump. Not everyone feels the need to pull this screen on a regular basis, but my experience has caused me to do it more often than most folks.

Originally, the oil temperature probe is installed in the pressure screen. Depending on the model of oil filter installed, the temp sender may have been moved over to the suction screen. The F&M filter has provisions to install the temperature probe in the back of the filter adapter as shown below.

Miles

tshort · Post by **tshort** » Tue Sep 12, 2006 6:17 am

You guys are fast!
My oil temp probe is installed in the smaller screen. Doesn't sound like I need to mess with that as I'm pouring out of plastic ... no old metal cans!

Thanks!
Thomas

Post by **GAHorn** » Tue Sep 12, 2006 1:01 pm

cessna170bdriver wrote:.. The suction screen is much smaller in diameter that the pressure screen, and is normally a coarse screen (unless a TCM service bulletin whose number I don't recall has been complied with, in which case it is a fine screen like the pressure screen)...
Miles

That was TCM SB 96-4 "Improved Oil Pump Gears and Suction Screens" which changed what we call the suction screen from a coarse perforated tube to an actual coarse screen, which provides greater "screening" surface area but only slightly better oil "filtration" (if you can call a screen a filter.) The only example I've seen is not as fine a mesh as the original pressure screen but is actually quite coarse. (I suspect it was cheaper to make than the perforated tube. The real object of the SB was to introduce new style pump gears, and it is not applicable to the early style case covers that used a square-drive pump gear, so it's unlikely many engines will be seen with this change.)

cessna170bdriver · Post by **cessna170bdriver** » Tue Sep 12, 2006 2:19 pm

As I remember (

) the drawings I saw depicted a screen about the same mesh as the pressure screen, but I've never seen one for real, as I could find no source for it. I have seen the coarse screens with the larger diameter wire, but not on a C145/O-300.

FWIW, Once upon a time, I found gear teeth in my suction screen. Upon removal of the accessory cover, I discovered that the rear bearing in the generator had failed and allowed the generator gear to bounce in and out of mesh with the inner teeth of the cam gear. On another occasion, I found a crescent-shaped piece of a valve lifter body face. On neither occasion was there enough metal in the pressure screen or filter to cause concern. I usually pull the suction screen about every other oil change just to make sure that there are no loose parts in it.

Miles

Post by **GAHorn** » Tue Sep 12, 2006 2:51 pm

Yeah, it's certainly "finer" than the perforated tube, but it's not so fine as the pressure screen. If anyone does pull that suction screen, be especially careful of allowing any debris to enter the pump uptake. Many turbine engines require an oil pump overhaul if the suction screen is disassembled and for that reason I've always been been loathe to take it out without due cause, but you are correct, Miles. The TCM Overhaul Manual for this engine calls to remove the oil "screens" (meaning both suction and pressure) every 100 hours for cleaning and inspection. Use a new gasket whenever you do so.
Thanks for making me look it up.

cessna170bdriver · Post by **cessna170bdriver** » Tue Sep 12, 2006 5:01 pm

gahorn wrote:...If anyone does pull that suction screen, be especially careful of allowing any debris to enter the pump uptake....The TCM Overhaul Manual for this engine calls to remove the oil "screens" (meaning both suction and pressure) every 100 hours for cleaning and inspection. Use a new gasket whenever you do so.

If there's any debris in this area, it "should" be in the interior of the screen, but when I have the suction screen out, I always clean its cavity in the accessory cover just in case anything fell out of the screen upon removal. Anything left in the cavity WILL get sucked up into the oil pump. My accessory cover is a later version with plugs under the oil screen cavities so they can be flushed if desired.

Miles

The International Cessna^® 170 Association

How much oil?

How much oil?

Re: How much oil?