Oil Pressure relief spring

How to keep the Cessna 170 flying and airworthy.

Moderators: GAHorn, Karl Towle, Bruce Fenstermacher

User avatar
Bill Hart
Posts: 455
Joined: Tue Aug 23, 2005 2:04 pm

Oil Pressure relief spring

Post by Bill Hart »

Can some one tell me the part number and a source for a new oil pressure assembly?
User avatar
Bruce Fenstermacher
Posts: 10422
Joined: Tue Apr 23, 2002 11:24 am

Post by Bruce Fenstermacher »

Bill if your looking for the spring it's #637083 the plunger is #21114 and the acorn nut is #21113.

I bought the spring for $6.13 from http://www.aircraft-specialties.com/. They have the plunger for $44.53 they don't seem to have the acorn nut

CessnaParts.com http://www.cessnaparts.com has all three at the following prices: #637083 @ $9.94, #21114 @ $61.07 and #21113 @ $91.54

Preffered Airparts http://www.preferredairparts.com has 117 used nuts #21113 and 12 #21114 plungers and they generally sell new parts for half list and used parts even cheaper
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
User avatar
cessna170bdriver
Posts: 4115
Joined: Mon Apr 22, 2002 5:13 pm

Post by cessna170bdriver »

Oil Pressure Relief Valve Spring: part number 637083 .

Oil Pressure Relief Valve Plunger: part number 21114 .

Try entering the part numbers at Premier Aviation.

You can also try Superior Air Parts.

Miles
Miles

“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
User avatar
GAHorn
Posts: 21295
Joined: Fri Apr 12, 2002 8:45 pm

Post by GAHorn »

cessna170bdriver wrote:Oil Pressure Relief Valve Spring: part number 637083 .

Oil Pressure Relief Valve Plunger: part number 21114 .

Try entering the part numbers at Premier Aviation.

You can also try Superior Air Parts.

Miles
WHAT? You forget to recommend Premium Aircraft Parts? :lol:
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
User avatar
lowNslow
Posts: 1535
Joined: Mon Apr 22, 2002 4:20 pm

Post by lowNslow »

Are these part numbers for the O-300 or the C-145, which seems to require a lower oil pressure?
Karl
'53 170B N3158B SN:25400
ASW-20BL
User avatar
Bruce Fenstermacher
Posts: 10422
Joined: Tue Apr 23, 2002 11:24 am

Post by Bruce Fenstermacher »

They are for every Continental from the A65 through the 0-300-D and maybe more but I don't have a parts manual for the rest.
CAUTION - My forum posts may be worth what you paid for them!

Bruce Fenstermacher, Past President, TIC170A
Email: brucefenster at gmail.com
User avatar
cessna170bdriver
Posts: 4115
Joined: Mon Apr 22, 2002 5:13 pm

Post by cessna170bdriver »

gahorn wrote:
WHAT? You forget to recommend Premium Aircraft Parts? :lol:

:evil: :evil: :evil: :evil:
Miles

“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
User avatar
cessna170bdriver
Posts: 4115
Joined: Mon Apr 22, 2002 5:13 pm

Post by cessna170bdriver »

lowNslow wrote:Are these part numbers for the O-300 or the C-145, which seems to require a lower oil pressure?
Using a new spring and plunger of the above part numbers, with the original cap (along with a major overhaul), my O-300A’s oil pressure indicates between 53 and 57 psi (Phillips 20W50), depending on temperature. The gauge pics were taken at 0.2 and 0.5 SMOH, respectively.

Image Image Image
Miles

“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
User avatar
GAHorn
Posts: 21295
Joined: Fri Apr 12, 2002 8:45 pm

Post by GAHorn »

What rpm?
'53 B-model N146YS SN:25713
50th Anniversary of Flight Model. Winner-Best Original 170B, 100th Anniversary of Flight Convention.
An originality nut (mostly) for the right reasons. ;)
User avatar
Bill Hart
Posts: 455
Joined: Tue Aug 23, 2005 2:04 pm

Post by Bill Hart »

cessna170bdriver wrote:
gahorn wrote:
WHAT? You forget to recommend Premium Aircraft Parts? :lol:

:evil: :evil: :evil: :evil:
Thank you every one. And I wouldn't touch Premium with George's ten foot pole :D
User avatar
cessna170bdriver
Posts: 4115
Joined: Mon Apr 22, 2002 5:13 pm

Post by cessna170bdriver »

gahorn wrote:What rpm?
2650 in these photos, but the oil pressure doesn't seem to vary much as long as RPM is in the cruise range.
Miles

“I envy no man that knows more than myself, but pity them that know less.”
— Thomas Browne
User avatar
lowNslow
Posts: 1535
Joined: Mon Apr 22, 2002 4:20 pm

Post by lowNslow »

cessna170bdriver wrote:Using a new spring and plunger of the above part numbers, with the original cap (along with a major overhaul), my O-300A’s oil pressure indicates between 53 and 57 psi (Phillips 20W50), depending on temperature. The gauge pics were taken at 0.2 and 0.5 SMOH, respectively.
Same here, but according to everything I can find it should be 30-45 psi for a C-145.
Karl
'53 170B N3158B SN:25400
ASW-20BL
N2865C
Posts: 507
Joined: Sat Oct 18, 2003 9:07 pm

Post by N2865C »

lowNslow wrote:
Same here, but according to everything I can find it should be 30-45 psi for a C-145.
Karl,
I don't have the overhaul manual and parts catalog in front of me, but I believe the specs and the oil pressure relief part numbers are the same for the O-300A and the C-145 (better double check me on that). I had questions about my high oil pressure in my O-300A and this is the answer I got http://cessna170.org/phpBB2/viewtopic.p ... l+pressure
Makes sense to me.......
John
N2865C
"The only stupid question is one that wasn't asked"
User avatar
Bill Hart
Posts: 455
Joined: Tue Aug 23, 2005 2:04 pm

Post by Bill Hart »

Check out this thred high oil press
http://www.cessna170.org/phpBB2/viewtopic.php?t=1246
User avatar
lowNslow
Posts: 1535
Joined: Mon Apr 22, 2002 4:20 pm

Post by lowNslow »

Both of these threads indicate an O-300. The TDC indicates a oil pressure of 30-40 psi for both the O-300 and C-145. The Operators Manual states a oil pressure of 30-45 psi for the C-145 and 30-60 psi for the O-300. These are old sources - the TDC is dated March 1974 and the Ops. Manual is undated is undated but seems to be around the same vintage. I am just looking for some official documentation with updated allowable oil pressures if one exist.
Karl
'53 170B N3158B SN:25400
ASW-20BL
Post Reply
Cessna® is a registered trademark of Textron Aviation, Inc. The International Cessna® 170 Association is an independent owners/operators association dedicated to C170 aircraft and early O-300-powered C172s. We are not affiliated with Cessna® or Textron Aviation, Inc. in any way.