TO35 oil pressure

[Dan from BC]

I recently bough a TO35 and figured the oil presure gauge or sender was not working; I get no reading. But then under heavy load I saw the gauge move. How do I test the gauge and sender?

 

[Jerry/MT]

I think your oil pressure gauge is just a Bourdon tube mechanical gauge and it has no "sending unit". It's hooked up to an oil gallery via a fitting & tube and it just reads the pressure in the gallery. It's possible that the tube is clogged or pinched but unless it's pinched or blocked totally closed, you should get a reading since the gauge system is deadheaded. Disconnect the tube from the block fitting, momentarily start or crank the engine and see if you have oil comming out of the fitting. If you do, reconnect it and disconnect it at the gauge and repeat, If you have oil comming out at the gauge then you don't have a blockage.

If you can find a 0-60 psi gauge that will attach to the fitting on the engine block, you can use that to see what the oil pressure is and if reads in the proper range, then you'll know your regular gauge is damaged.
The only way I know of checking it for accuracy is to pressurize it with a known pressure and check the gauge reading.

By the way, the gauge might be OK and you might have a damged relief valve, worn oil pump, or worn main bearings. You need to know before you cause some serious damage to your crankshaft.

 

[Xwild]

Out of curiosity, what should proper pressure be on a TO-35? My gauge is currently reading about 17-18 lbs?

 

[Jerry/MT]

What's the owners manaual or the shop manual say? I have a Z129 Continental on my TO-30 and the normal oil pressure, hot or cold is 27 psi on the gauge. The shop & owners manuals say that the oil pressure at operating temperature and idle speed(400 rpm) should be no lower than 15 psi. This engine is similar to the Z134 in the TO-35.

 

[Dan from BC]

Thanks Jerry, I do have a pressure gauge. I'll give it a try.

 

[Dan from BC]

I bought a manual from ebay but it turned out to be a .pdf file on a cd ... not too convenient.
Also it does not seem to talk about the power steering. Do the manuals on this site cover my version TO 35 deluxe?

 

[Jerry/MT]

If its OEM power steering than it should be covered.I don't own a -35 so i can't answer that question directly.