Thread: Why would S2A Oil light comes on when I brake hard?

It's called oil surge.

The sump isn't baffled, so when you brake hard (can you actually brake hard in a Series ?? ) the oil surges forward and is uncovering the pickup which cavitates the pump, resulting in zero oil pressure.
This isn't good, and many production race cars of yesteryear 'did' engines from this phenomenon under brakes and hard cornering.

I'd increase the oil level slightly and see if it still does it, if so, drop the sump, maybe the pickup is cracked ?

Inertia! When you brake hard the oil in the sump continues moving forward until it is all at the front. This allows the oil pickup to suck air which is easier to pump than oil, the oil pressure drops and the light comes on.

Check that you don't have low oil level in the sump and it may be worthwhile to check that the pickup hasn't been bent so it is sitting too high in the sump. This will however require that you remove the sump for the check.

Diana

The 2.25 engine has three levels marked - Min, low and high. It should NEVER be operated below Min, but it is allowed to be operated between Min and low, but only on level ground, as they note that oil pump starvation is likely when the vehicle is facing downhill at a steep angle - effectively the same as when braking heavily.

If you are seeing this effect with the oil above low, I would suspect that you may have a problem with the dipstick - perhaps the collar has moved on it or it is the incorrect dipstick, or the tube it goes into has been shortened.

There is a possibility that the effective oil intake is higher than it should be, as Diana suggests.

John

Thanks for the great feedback...OK, hard-ish braking Checking the oil, yep it's just at low (I needed to move to a level spot to check for sure cos my driveway is slight downhill slope) you won't be surprised to know that Hillston leaks oil...I didn't think it was engine oil leaking though. I'll top it up and see if this helps.
I didn't see this covered in the owners manual?? Cheers Les

Originally Posted by 65s2a

......
I didn't see this covered in the owners manual?? Cheers Les

Page 43 in mine (June 64)

John

Brakes! You have a 2A with brakes?

"Porco Dio, Porco Madonna", as the maestro of Molsheim, Sr. Ettore would say. "I make my cars to go, not stop."

bwhahaha i just got all my brakes overhauled, skimmed drums, new pads, new slave cylinders, sleeved master cylinder I CAN LOCK WHEELS in the dry!!!

And yes I was only thinking yesterday about posting a thread on exactly the same topic as I have the same problem. Will check oil levle again (seems good) although I have a very bad rocket cover leak - is oil pooling on the head next to the rocker cover bad??? hahaha

Originally Posted by Newbs-IIA

....... - is oil pooling on the head next to the rocker cover bad??? hahaha

Not necessarily - it helps to reduce rust on the chassis. But you need to keep an eye on the oil level. Almost certainly the rocker cover gasket, easily replaced. Note that the closed nuts on top of the rocker cover will tighten on the end of the studs without applying pressure on the gasket if the rubber washers under the steel washers have compressed and gone hard. Also make sure it is not the oil line to the back of the head is loose - if the union on this comes completely out you will very smartly lose all your oil.

John