Common oil leak? MFI fuel pump drive wheel.

[SRL]

I have my engine out of the car for repairs of various oil leaks and general cleanup. A question: The gear wheel that's attached to the driver side camshaft, drives the MFI fuel pump. There is a seal at the cam where it protrudes from the camshaft housing, where the wheel attaches. It looks like a miniature rear main seal. Is this frequently the cause of an oil leak? Mine's not leaking now but now would be the time to replace it, while the motor is out. Unfortunately it's not like the RMS, where it's right there and easy to get to - it's kind of down in there, hard to get to. Because it's so narrow, I can't see how to "grab" it to get it out. Then, re-installing would be a bit of a challenge as well, albeit not insurmountable.

Anyone ever replaced this seal while the can housing was still on the car and the cam was in place?

[beh911]

Yes, the cam tower pump drive seal is a frequent cause of leaks.

I have also heard that sometimes replacing the seal does not fix the leak. There is some wear over time that a new seal may not address.

Others will chime in on technique for removing it.

[rick2]

There is room for two of the original style seals and can be done with engine in car but you will need to remove the drive gear. New part # is 999 113 068 50
Description; Injection Pump Drive Seal on Camshaft Carrier

[SRL]

There is room for two of the original style seals and can be done with engine in car but you will need to remove the drive gear. New part # is 999 113 068 50
Description; Injection Pump Drive Seal on Camshaft Carrier

So you're saying just tap a new one in over the existing old one?

[bliebler]

A mechanic, who works on allot of MFI ,cars told me when replacing this seal use the orange or brown color seal. He claims that the black color seal is harder and does not fit as tight. During my rebuild I used a little RTV silicone when mounting into the cam housing because my previous seal showed signs of walking out. Also, grease the shaft and the lip of the seal which goes over the shaft.

[rick2]

SRL After taking off the gear you will see the seal clearly and I use a curved seal tool and work the old one out from the housing starting with the cam side of the seal. I've only used the german brown seals from Porsche. You never want to install a seal "dry" so I use a small amount of the Bosch distributer lube on the inner part of the seal that touches the drive. I'm a red neck and use a deep socket that fits over the drive but still will fit inside the cam housing (26mm if memory serves) and insert seal cupped side in flat side out. Drive the seal in about 5mm past the cam housing and then I use the additional seal and repeat the process but stopping flush with the housing. These are only good for about 2 race seasons then the engines come apart anyhow.
My humble $.05 Use what part of the directions you want. I am not politically correct so Merry Christmas!

[SRL]

2 race season sounds perfect considering the mostly mellow and low street mileage this motor will see! Thanks for the tip!

[s-bonhomme]

I have a MFI pump out of the car and see that the seals are made of orange silicon, on all . I have a ? how do I flusch my MFI pump and whit what product ???
thank you

[wicks]

Bumping this thread to see if anyone knows of a newer technique to fix this? Saw a couple mentions of a cover that holds the seal better or something but searching not turning up any results on that.

Is it still two OEM seals, (brown?) placed in succession on the cam?

Original 911s 1973 motor, this is the only leak.

[2.5MFI]

I have had excellent results using the KOCO Vitron seal 35 x 45 x 7 mounted in a alum cover plate that bolts up to the cam housing.