Oil pump housing (pressure relief!)

[bloodysalmon]

The photo shows the block casting exterior for the oil-pump. At the top middle you can see an insert with a thread inside that. I'm assuming, because there appears to be a ball bearing behind that this is the pressure relief, that this is also removable ... how? Should I bother removing it? I'd do it IF pressure was previously low before a rebuild ... but I dont know.
So is there an easy way to remove the outer-bung, ball and ball cage?

IMG_0246 small.JPG (54.27 KiB) Viewed 1456 times

[Tom Wilson]

Chris - I think it’s threaded to use a puller.
Make a steel plate that spans across to a pair of the 1/4” holes. Drill 3 holes in the plate - 2 for 1/4” screws, 1 for the center one (I think it’s 5/16 but don’t recall for sure.
Put a pair of threaded rods in the 1/4 holes with nuts on them. Place the plate on these, screw in a bolt into the center, then back off the 1/4 nuts to lift the plate - or tighten the center bolt to pull the piece out.

Tom Wilson

[bloodysalmon]

ok Tom, just to confirm, you think it's internally threaded to allow pulling extraction yes? So I presume it would be press fitted, externally tightly inserted? If this is the case perhaps there was an extraction tool made for it originally too.
My secondary question was to its removal along with the ball and cradle. What value is there in removing it ... if its to clean thats fare enough, but to replace it ... why would you or how could you determine if it needed to be replaced?

My other question I must ask is ... once the pump is fitted to the engine/block and also fitted into the mounts cradled in the chassis ... can you actually remove the pump WITHOUT raising or removing the engine? Based upon the fact the majority of the 8 pump bolts hit the chassis, preventing stud removal.

[ROGER FURNEAUX]

The XPAG is a METRIC engine! The oil pump bolts are 6x1.0mm, and the plug you are referring to is most likely 8x1.0mm: certainly the idler gear shaft is threaded for the same reason. And even if tools were available back in the day, they are long gone, so we have to bodge it!

Roger

[bloodysalmon]

Hi Roger, appreciate the xpag is metric, I have 3 engines to maintain ... so is the bung threaded inside and outside then? If it needs to be extracted I'd assume its only threaded on the inside!

[Tom Wilson]

Chris, it’s only threaded on the inside and is a pressure fit.
Removing it allows for cleaning.
Roger is correct on metric threads. Being an American I have difficulty in accepting anything other than the inch system,though I’ve appreciated the simplicity of metric many times. 2.54 is a number I frequently use.
Tom

[bloodysalmon]

being sure it was only a pressure fit allowed me to remove the brass cover easily with a tube, washer and spanner to whind out ... it dropped out along with a very rusty 1/2" ball bearing so it was already a worthwhile task. What I ask now is what method we use to extract the ball cradle piece? It looks to be a little fragile so I dont wish to break it. Perhaps WD40 along with 2 screw drivers inserted and then twisted will do it?