How to Replace MFI Pump Drive Seal?

[73ess]

Getting a leak from the pump drive seal on left side cam in my 73T. Anyone have experience replacing one with the engine in the car? Tools needed? Best procedure? Here's the seal.

[edmayo]

Remove heat exchanger, cover plate, unbolt pump pulley (two 5mm allen bolts) if you're careful you can just swing pulley aside with cog belt still on, and if you don't rotate engine you can usually bolt it back up without loosing pump timing. Use your seal removal tool to lever out old seal, and then there is a special Porsche tool that drives in the new seal to the right depth. Lacking that take careful note of seal depth before removal and be creative with pieces of pipe to install new seal to same depth. Always double check pump timing when done.

[73ess]

Remove heat exchanger, cover plate, unbolt pump pulley (two 5mm allen bolts) if you're careful you can just swing pulley aside with cog belt still on, and if you don't rotate engine you can usually bolt it back up without loosing pump timing. Use your seal removal tool to lever out old seal, and then there is a special Porsche tool that drives in the new seal to the right depth. Lacking that take careful note of seal depth before removal and be creative with pieces of pipe to install new seal to same depth. Always double check pump timing when done.

Thanks Ed. First, is removing the heat exchanger a must? I've got the left rear wheel removed and car jacked up from the left side. Looks like I can get to the bolts securing the cover plate without much trouble. But can I get to the seal without too much effort with the heat exchanger in place? My car was converted to carbs, so no need to worry about loosing pump timing. Don't have a seal removal tool. Was thinking just tapping the seal with a small punch will pop out the edge of it to ease removal? Do I need to to lube the new seal with something prior to insertion?

[edmayo]

As you say, there is some access without removing the heat exchanger, but to me the aggravation isn't worth not removing it. Tried it once, that's why I remove it. The Porsche seal tool is a mandrel that you use to hammer in the seal, not much swinging room with exchanger on. The seal removal tool is a common generic tool, worth buying, don't think tapping in with the punch will work, seal not that wide, too much chance of nicking bore. Just lube lip with engine oil.