N62 engine valve stem seals

[jpcallan]

Originally Posted by Westlotorn

The vacuum pump has two seals, an inner and an outer that can leak, both are O'Rings. The part numbers are shown in this forum but I don't have them handy. One is available at the BMW dealer but the other is not. You can get both from one of the aftermarket BMW parts houses, I found the part numbers on this forum when I did it. I tried an aftermarket oring from Napa first, it worked but was a little too large. The BMW house had a better set of O'Rings.

Dorman offers a vacuum pump repair kit, P/N 917-146, that services the engine drive coupling O-ring, the big pump case O-ring, and includes five replacement pump cover screws in case these get damaged taking it apart. The price for this kit is expensive for what you get, all over the map: $53 to as little as $25; plenty of people sell it on eBay.

The latest pump engine drive O-ring from BMW sells for about $10 MSRP, P/N 11667509080 (07119903506, 11660151057). The numbers in the parentheses are still valid, but superseded BMW P/Ns.

BMW doesn't service the case O-ring, instead selling a whole new vacuum pump. My friend Dave got clipped for $625 in November, 2017, for a leaking case O-ring.

A month or two ago, I found this table data describing the vacuum pump O-rings on Dorman's website (reformatted here):

Case O-Ring
------------
Maximum Inside Diameter 93.66
Maximum Outside Diameter 96.76 mm
Maximum Thickness 3.10 mm
Minimum Inside Diameter 92.34 mm
Minimum Outside Diameter 95.24 mm
Minimum Thickness 2.90 mm
-
Engine Drive O-Ring
-------------------
Maximum Inside Diameter 53.45 mm
Maximum Outside Diameter 56.55 mm
Maximum Thickness 3.10 mm
Minimum Inside Diameter 52.55 mm
Minimum Outside Diameter 55.45 mm
Minimum Thickness 2.90 mm; 2.90 mm