The International Cessna^® 170 Association

Can some one tell me the part number and a source for a new oil pressure assembly?

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

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

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?

Are these part numbers for the O-300 or the C-145, which seems to require a lower oil pressure?

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.

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

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.

What rpm?

cessna170bdriver wrote:

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

Thank you every one. And I wouldn't touch Premium with George's ten foot pole

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.

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.

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.......

Check out this thred high oil press
http://www.cessna170.org/phpBB2/viewtopic.php?t=1246

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.