Missing sump bolt?

Ask Questions and Offer Advice Related to the Cessna 120 & 140 Type
Forum rules
You must be a member of the Cessna 120-140 Association in order to post new topics, reply to existing topics, or search for information on this forum. Use the "Join" link in the red menu bar.
Post Reply
mbruffy
Posts: 8
Joined: Fri Jan 17, 2020 9:27 pm
Name: Matt Bruffy
Location: Texas
Aircraft Type: C140
Occupation-Interests:
Contact:

Missing sump bolt?

Post by mbruffy »

Missing bolt
Missing bolt
IMG_7005.jpeg (447.69 KiB) Viewed 2211 times
I just noticed a bolt missing on the backside of the oil sump that also holds the exhaust bracket in place. Does anyone know the part number for a replacement bolt/washer and also torque? Thanks!
User avatar
6643
Posts: 2455
Joined: Tue May 01, 2018 7:00 am
Name: John C
Location: KLCI, NH
Aircraft Type: 1946 C140/C90
Occupation-Interests: A&P, semi-retired
Contact:

Re: Missing sump bolt?

Post by 6643 »

It's a stud that screws into the accessory case, then nut and washer. Since it fell out, the new stud will probably not hold. There may be is an oversize stud you can use, or drill it and saftie it.

Stud 401804 1-1/16"x 1/4" Oversize parts are available, see Continental C-series Parts manual.

It calls for plain washers and elastic stop nuts. Both have Continental part numbers, 20522 and 22661 respectively. There is a reduced hex, metal stop nut available. It makes installation a lot easier. MS21042-4.

Torque for the nut can be found in AC43-13.1b. Installation of the stud is probably discussed in the C-series Overhaul Manual.

Something about that support bracket doesn't look right...
mbruffy
Posts: 8
Joined: Fri Jan 17, 2020 9:27 pm
Name: Matt Bruffy
Location: Texas
Aircraft Type: C140
Occupation-Interests:
Contact:

Re: Missing sump bolt?

Post by mbruffy »

Thanks. Yeah like the diameter of that bracket hole is too small. Makes me think if there has ever been a stud there🤷🏽‍♂️
mbruffy
Posts: 8
Joined: Fri Jan 17, 2020 9:27 pm
Name: Matt Bruffy
Location: Texas
Aircraft Type: C140
Occupation-Interests:
Contact:

Re: Missing sump bolt?

Post by mbruffy »

Maybe I’m missing something, I probably am, but could I drill out the bracket hole to a larger diameter and just put a bolt in place there?
V529
Posts: 592
Joined: Tue May 01, 2018 7:00 am
Name: Victor G
Location: Michigan
Aircraft Type: C-120
Occupation-Interests: Work on airplanes till the cows come home..........they're still out.
Contact:

Re: Missing sump bolt?

Post by V529 »

mbruffy wrote: Mon Sep 09, 2024 1:23 pm Maybe I’m missing something, I probably am, but could I drill out the bracket hole to a larger diameter and just put a bolt in place there?
Possibly, or the hole is just an optical illusion? You can try a bolt, it's probably coarse thread........... Studs typically have a slightly different thread pitch, be careful as you screw something in there. I'd try John's recommendation first.....
User avatar
6643
Posts: 2455
Joined: Tue May 01, 2018 7:00 am
Name: John C
Location: KLCI, NH
Aircraft Type: 1946 C140/C90
Occupation-Interests: A&P, semi-retired
Contact:

Re: Missing sump bolt?

Post by 6643 »

Yeah, the threads in the accessory case will be coarse, and you will have a hard time finding a bolt to fit.

I think that's a blind hole, too, so if your bolt is too long you'll cause more problems.

That bracket must have been secured at one time or another, so the hole must be the right size for whatever was there. The fact that it fell out points to fixing it right, or you'll be fixing it again. Find out why the holes don't align, and use the right fasteners. Safety wire might be a good idea, too.

What exhaust system do you have on there? Check and make sure you have the correct parts for your installation.
edidin
Posts: 158
Joined: Mon Jul 19, 2021 8:57 pm
Name:
Aircraft Type:
Occupation-Interests:
Contact:

Re: Missing sump bolt?

Post by edidin »

To the naked eye the hole in the bracket looks closer to 3/16 whereas the stud that goes there is 1/4.
mbruffy
Posts: 8
Joined: Fri Jan 17, 2020 9:27 pm
Name: Matt Bruffy
Location: Texas
Aircraft Type: C140
Occupation-Interests:
Contact:

Re: Missing sump bolt?

Post by mbruffy »

Thanks for the advise. They’re straight pipes.
User avatar
6643
Posts: 2455
Joined: Tue May 01, 2018 7:00 am
Name: John C
Location: KLCI, NH
Aircraft Type: 1946 C140/C90
Occupation-Interests: A&P, semi-retired
Contact:

Re: Missing sump bolt?

Post by 6643 »

mbruffy wrote: Fri Sep 13, 2024 7:38 amThey’re straight pipes.
Maybe it's just the angle of the photo, but, that bracket doesn't look right. It appears that one tube intersects the other. They should form a "V" with the flat plate that has the tab with the hole at the point. The part is symmetrical left and right.
Post Reply