Oil Pump Replacement - What to expect?

[exitwound]

Going to change out the oil pump on the car. Having consistent oil pressure problems and it's the only thing left in the equation that hasn't been changed.

Looks like a pretty straight forward procedure. Haven't had the timing off the engine since it was put together ~2000 miles ago. I'm pretty familiar with it all, but have only done it once.

What should I expect? What should I look out for while I'm in there? What are some precautions I should take before starting?

Looking for your experience here so that my job goes smoothly.

[Techno Duck]

Make sure you have Loctite 574 on hand for reinstallation. Also be careful with the threads on obth removal and installation. The aluminum threads really strip very easily. I stripped a few (even being careful) when i replaced the pump on my friends '85. I ended up heli-coiling every single one of the threads on the front of the block for the waterpump and oil pump. A long day spent with the drill and tap.

Its really not a bad job, just a pain in the butt because the pan has to come off.

[exitwound]

Can't you drop the pan a little bit and slide the pump out? Do you have to drain the oil?

[Techno Duck]

You can squeeze it out, but i would be hesitant to go through that much trouble and end up with a leaking oil pan gasket afterwords.

[exitwound]

Taking the pan off, according to clarks, is a weekend event. Crossmember dropping, power steering draining etc.

[Techno Duck]

Im guessing you never dropped the pan before? Did you check rod bearings, oil pickup tube..etc first (i guess it was done by the PO or at a shop?). The oil pumps on these cars have pretty good track records, but anything is possible.

But yes, dropping the pan takes some time. Nothing necessarily hard to do, just time consuming.

[exitwound]

All bearings were changed when we built the engine ~2000 miles ago. Pickup tube was checked at the time, but not since. The original pump's gears were rusted closed (the original owner left it in the rain when off the car), and so we had to replace them. When we did, the pair we used weren't much better. Spending the $800 for a new one wasn't plausible and still isn't. I'm using another used one from a car that was known to work. Crank bolt torque has been redone multiple times. OPRV was cleaned, then changed as well.

When cold, pressure is 4.5-5bars. When warm, 1bar, sometimes less. 25W50 oil is in it.

[exitwound]

For anyone reading this, it's not possible to get the oil pump off the car without dropping the oil pan, and probably not even then. There's one bolt that holds on the oil pump that's obscured by the lower balance shaft appendage that holds the power steering up. It's IMPOSSIBLE to remove with the shaft in place. How clark's managed to do it is beyond me. I spent 8 hours today attempting it and got absolutely nowhere because that one bolt doesn't come out unless that balance shaft is removed.

Stupid car.

anyone wanna buy it?