230SL Injector Pump Oil Check Valve

[mistertj]

Trying to determine the diameter of the ball in the injector pump oil check valve. While taking mine apart for cleaning, the ball "jumped" out and went on to the garage floor and promptly disappeared. It's likely that I will not find it soon so looking to find the diameter so I can replace.
p.s. I have read previous posts that seem to imply that maybe there is no "ball" but I distinctly remember one falling out when taking apart the check valve. Also there is spherical detent in the check valve housing that looks like where the ball should reside.

[Kevkeller]

I’d get a large magnet and go over the entire place.  Home Depot sells them for picking up nails.

[mistertj]

Tried the magnet thing but no luck. 

[Bonnyboy]

The last time I lost something that small I had to vacuum my entire shop - it was amazing what I found and I found the teeny spring I lost - start with  clean bag and go at it - crevice tool at corners too.  It has to be there.

Good luck.

   

[Kevkeller]

Put some panty hose on the end of the vacuum when you do that.

[mistertj]

Did the careful search on the garage floor, the magnet, the vacuum and etc. No ball! 
The cylindrical hole and ball socket look to be around 4 to 4.5mm. So, until someone lets me know what the proper size is, I'll go with one of those.

[wwheeler]

Does your check valve look like the picture toward the bottom of this thread?  https://www.sl113.org/forums/index.php?topic=26687.msg191048#msg191048

If it were me, I would do some more extensive research to be 100% certain that there is a ball in there. If you somehow stop the flow of pressurized oil to the pump, you will ruin the IP cylinders.

[mistertj]

I hear ya ...Wallace. That would be my plan. Fortunately this is not the oil check valve off my running car but a spare junk injector pump that I picked up and was cleaning along with trying to get it unstuck and learn how the pumps work...or don't. Like the other gentleman that wrote about losing the ball, I distinctly remember a ball coming out of the fitting as I took it apart on the workbench. Here is a photo of what I have.

[wwheeler]

That is exactly what I had in mine. But nothing else and no ball. It really doesn't make sense to have anything else. That torpedo looking thing is the check and is pushed to it's seat by the spring. As the oil pressure inside the engine exceeds the pressure inside the pump and the spring force, it allows more oil in. When the engine is not running and at zero pressure, this check keeps the oil pressure inside the IP. So upon start up, there is already pressure there to seal the cylinders.

Did you also lose a spring or was it just a ball? If it was just a ball, it has to have some spring device to be a check valve. 

[Benz Dr.]

If we are talking about the oil lock that's in line then they're all cone shaped valves in everything I've seen.  Later 280's didn't have this check valve and were flow through back to the crank case. You either have one or you don't but I've never seen a ball in any of them.

I hope we're not confusing this with the IP valves which did use balls on the later units.

[wwheeler]

I hope we're not confusing this with the IP valves which did use balls on the later units.

His picture above shows the earlier style, so should be the cone check only. No ball. I do have both styles of IP checks - 220SE and 280SE and yes, they are quite different. Being these cars typically have had several owners by now, it is entirely possible someone put a ball in their because they thought it should have one. Just because it was in there, doesn't make it 100% correct. That is part of the sleuthing fun of restoring old cars. Previous owners have been known to do some stupid things. My 220SE was full of them.