When driving home recently I noticed I had only half the oil pressure that I normally have about 30 psi and I run actually about 70-75 psi. When I would come to a stop, the pressure would drop to almost 0 so I would keep the revs up a little to keep the pressure up some. I thought it might be the gage or maybe the oil pump had loosened from the block. It turned out it was oil level. I had dismissed oil level in my mind because I check level so frequently. It was my vacuum pump. The diaphragm had broken and was sucking the oil out of the sump and putting it on the ground. I don't think I did any engine damage. I am just glad I noticed it. This issue is definitely a flaw with this engine. Rebuilding the vacuum pump is no big deal. I installed my spare pump and I was good to go. A couple of tricks I have learned: 1) when rebuilding the pump, check the 2 plates that sandwich the diaphragm and make sure they are very smooth especially on the edges as the metal plate and rubber diaphragm rub on one another when going up and down. 2) put a little lubricant on the diaphragm so that where it rubs on the plate, it is lubricated 3) when you install the diaphragm cover, do so with the diaphragm to the upper stroke extreme. This will cause the diaphragm to be mounted in such a way that the diaphragm will not have to stretch as much when the diaphragm is working because the diaphragm was "pulled in" from the start. 4) The pump is mounted on the side of the block at an angle like some of the old straight 6 distributors. When you pull the pump out, the hex sided drive shaft (which also powers the lube oil pump) falls/lays up against the bottom side of the hole and you can't reinstall the pump because the drive shaft does not line up. I get a very small piece of styrofoam and wedge it in between the drive shaft and the wall to center the drive shaft in the hole. The piece of styrofoam ends up in the oil. I assume it ends up as part of the oil as I know gasoline will consume styrofoam in a moment. I didn't know how else to make it happen. I guess you could jack up the drivers' side of the vehicle to make the pump strainght up and down. It would be way up there though. Or you could pack the hole with grease. That would probably work fine. I know it is rather detailed here, but this simple little diaphragm can destroy your engine. I think Marcoleo or Steve Coreze mentioned this in another thread. If you own one of the Renault diesel Jeeps, keep a spare vacuum pump rebuild kit on hand, watch your oil pressure when driving, check your oil level often and if you see a good splotch of oil on the ground in the vicinity of your pump investigate it. I have experienced this twice now. The first time I caught it early. The second I almost didn't. It was using a quart every 15 miles I suspect.
Nelson
