No Oil Pressure

[alwaysoar]

Has anyone had this kind of oil pressure problem: If the engine sits idle for more than a couple of weeks, I can't get oil pressure off the peg. I've addressed this by putting the plane almost on its nose by standing on a ladder and lifting the tail over my head--pretty bizarre and an interesting spectacle for passersby, that until today, worked. Today, no pressure despite the aforementioned remedy. I disconnected the oil pressure line from the case, and no oil pumped out with the engine at an idle. I've cleaned the screen, checked the pressure relief valve, and plan tomorrow to check the oil suction tube but since I had 40psi the last time I ran it, I doubt that is the problem. It also does not seem likely for the same reason that the oil pump is shot. Any ideas? Thanks,

Ed in BTV,VT

[robbie]

It sounds like the oil pump lost it prime, When you tip up the tail, oil in the upper galley runs back into the pump.
Oil should always be in the bottom half of the pump.
Pull the tach cable out and squart oill from an oil can into the screen, it will fill the pump.
I use to have the same problem,till I started to use 1/4 bottle of the racers edge in the oil. (STP) It clings to the gear and I haven't had a problem since. Started to use it 5 Years ago.
Robbie

[Robert Lees]

Err umm... correction, flyboy, remove the oil temp bulb to squirt oil into the screen.

Removing the tacho cable & squirting in there will result in some oily shoes.

Rob

[robbie]

Your right Rob, See what getting old does to you.
A few squrts should do it for him.
Robbie

[alwaysoar]

Rob and Robbie, Thank you, I'll do the squirting tomorrow. Just a few squirts? Probably I can't overdo it.

Ed @BTV, VT
N95645

[ROllerton]

Wear in the gears and things around let it loose its prime as the gap is too big to keep sealed with the oil film.

I think it also has something to do with the rear case cover wear too. I This was a popular topic a few years ago and I forget the details. But hopefully someone will speak up and we will have it captured here.

[G. Kent Brown]

alwaysoar...

Standing on a ladder and lifting the tail in the air sounds like a great photo op. And, I would like to catch the facial expressions of those observing on camera !

G. Kent Brown

[Steve]

No oil pressure

I just had that happen to me yesterday (after weeks in the shop tending to all of the problems with my new "toy"). Is there a permanant fix to this issue? I really kind of hope not because it sounds like a great excuse to fly the plane frequently!

I have now learned how to prime the oil pump, but finding out that there is no pressure after the start doesn't sound like a good idea. It needs some sort of a primer. It is probably best to just go through the procedure if it has been too long between starts.

[lktiller]

Others more familiar with this problem will reply I hope. But the essence of the previous discussions is the cover plate over the oil pump gears needs to be repaired or replaced. Also check the pump gears for wear. Clearance is the issue.

Some replacement covers may not be correct.

[alwaysoar]

I went so far today to remove the screen and pump quite a few squirts directly onto the gears and got pressure right away. The A&P who first told me to hold the tail up said it was a common problem. I've flown quite a few C-65's and never had it happen before however. It seems logical that there is wear in the gears or cover but then wouldn't there be a low-pressure problem when running? My pressure is right up there. It's an easy remedy to remove the temp bulb and squirt some oil in there which should do the trick until my 700-hour engine is due for an overhaul. My many thanks to this excellent forum for all the help!

[Garry Crookham]

Losing oil pump prime is usually caused by wear in the oil pump housing (the pocket in the accessory case where the oil pump gears reside). Continental specs indicate the max limit between the gears and housing is .0045 in. Drake Air in Tulsa has approval to rework the housing and install bushings in the holes for the oil pump gears. We have used them to rework several accessory cases....expensive- but cures oil pressure problems. The oil pump gears normally don't wear a lot, they are steel, but the housing is either magnesium or aluminum and usually shows quite a bit of wear.
The A65, A75 Overhaul Manual and Parts Catalog has a pretty good illustration of the accessory case showing the oil pump gears, housing, and cover plate.

Garry Crookham
N5112M
Tulsa, Ok

[Steve]

How expensive and how long is the turnaround? I don't like the fact that you don't know until after it starts, and it is a pain (and cold) to take apart and prime every time. What does a new pump run?

Thanks for the information,

Steve

[Garry Crookham]

Steve

The last accessory case we send to Drake Air cost about $600 to repair and turn around time was a couple of weeks. Drake Air builds up, and re-machines the pump housing and installs a bushing in the hole for the pump gear. It's expensive but cures the problem and saves the accessory case. Good accessory cases are becoming hard to find.


__________________

Garry Crookham
N5112M
Tulsa, Ok

[paulp]

Steve,

Gary is correct. I had several folks tell me that it wasn't necessary to have the acc case done-just put in new oil pump gears!! Fortunatly I'm not real bright so, I didn't listen and had the case done anyway!!!(Just a tad over $550.) It was a good thing I did.
They had to rebuild the oil counter bore and the Tac housing. They told me that had I not had the case done, I would probably have problems loosing the prime in the oil pressure hose and consequently, showing loss of oil pressure.

Best advise, bite the bullet and have the case done.

Regards

[captjon]

Steve:

Gary is correct on the high cost at Drake Air. They do a fine job, but get a lot for their work. My friend Marcel had his C85-12 accessory case done by them last year and all is well now. He had the same problem basically. He would have good pressure initially when started from cold, but if you turned it off, and started again there would be none. Lifting up the tail would get it back. Not exactly what I want under my cowling!

This all happenned before I started my new business, T-Restore.biz, LLC. Now I could help him out as I have found a source of Continental O-200 accessory cases for less than he paid for his repair. The C85-12 accessory case is the same.

For the A65's though, you can either have Drake Air fix yours, or buy a good used case. I have several on the shelf that I have cleaned up, visually and dye checked for cracks, and that should be serviceable. Fresno Air Parts also advertises "AF reconditioned" accessory cases for $395, although I haven't seen one and can't vouch for the quality.

First step I would take would be to take off the accessory case and see exactly what you have. It probably will be visually evident what is wrong. I have seen the gears too with wear along the shafts where they ride in the accessory case, even though they are steel and the cases are either aluminum or magnesium. Several of my gears have been rejected by my repair shop for "wear". More likely though is "scratches" or wear either on the cover plate or in the accessory case, or wear in the holes that the gear shafts ride within. "Slop" in the shaft should be quite noticable if that's the problem.

The gears can be had new too....a complete set of two and a new cover plate goes for around $200. I have some yellow tagged gears here too a little cheaper.

Check out the links below to see what the accessory case and oil pump area look like.

http://t-restore.biz/A4587_1.jpg

http://t-restore.biz/A4587_2.jpg

http://t-restore.biz/A4587_3.jpg

http://t-restore.biz/A4587_4.jpg

http://t-restore.biz/A4587_5.jpg

http://t-restore.biz/A4587_6.jpg

http://t-restore.biz/A4587_7.jpg

Pull yours apart and get with your I/A and see what he suggests. If you are interested in some help with parts, let me know. I still haven't got my web page going yet for T-Restore.biz, LLC but I am officially in business, bringing you both selected used Taylorcraft and small Continental parts.

In case you haven't been there yet, you might enjoy my web site too at http://taylorcraft.info

Cheers,