OIl pressure sender leaks, PN 901.741.551.01

[caproader]

Guys,

Did Porsche change the threaded fitting at the base of the MFI oil pressure sender (P/N#901.741.551.01) to a pipe thread?

As part of my on-going effort to decrease major oil spills, I recently purchased a new oil pressure sender at the dealer. However, when I tried to screw the new pressure sender into the sleeve that goes through the MFI oil line banjo fitting, the new pressure sender only went on about half the threaded length and then became tight. Just like the new pressure sender had a pipe thread, not a machine thread. The only way it will work is if I use about 4 or 5 crush washers to take up the spacing that formerly used just one crush washer (don't worry; not going there). And the threaded fitting sure does look like it has a taper when I mic'ed it.


So what's the story? The old part, even though it looks a little different from the new, has the same part number as the new one. But it definately does not screw in to the sleeve like the old one did.

All help greatly appreciated. Meantime, I reinstalled the old pressure sender with new crush washers and sent the kid out for a test drive.

John

73 S coupe with sporto and 73 T with MFI 2.7

[911quest]

The one I got the other day also had tapered threads. I used a little teflon tape and had no leaks....

[caproader]

Hey Tony.

Great to hear from you and good to hear that you're still alive and well in Louisville.

If I use teflon tape on the pressure sender threads, do you think that I will permanently ruin the machine threads in the sleeve (if I come down hard enough to seal the threads but not enough to mash the sleeve threads)?

Thanks for the help. I owe you a glass of sarsparilla when I see you next.

John

[911quest]

John,

The tapered threads do a great job of sealing I just use the tape cause it makes me feel more at ease. It won't mess up the threads.

Glad to also see that your still wrenching on the cars.

[caproader]

Oil leak is still there. Guess I'll have to install the new pressure sender and then look to see if it is leaking at the MFI Pump side of the mfi pump feeder line.

And I want to use this car for OneLapOfAmerica in a month.

Argh

John

[Fritter]

On oil fittings that leak, I use Permatex high temperature thread sealant and it fixes it every time. It comes in a little tube and it's white. I plan on using it on the two unused sportomatic oil fittings on my oil tank when I reassemble it and put it back in my '68.

[caproader]

Mike, Thanks for the thoughts. I'm going back out tot he garage later this afternoon to work on finding the leak source.

Meantime, would like to hear about your experiences with the sporto. Mine is tight around oil tank, but leaks around the torque converter and oil pump at the end of the cam shaft.

John

[Fritter]

Well, my '68 no longer is a sporto, it has a 901 5 speed in it now! The only remnants of it's sporto heritage are the goofy wires now, oh, and the two extra fittings on the oil tank.

Good thing about the sporto is it came with the oil level gauge and also S brakes!

[304065]

Are you certain the dealer gave you the right one? I agree, it sounds like you are trying to fit an 1/8" NPT sender (the normal VDO type) into the banjo bolt which is M10x1.0 (parallel thread).

To verify that you are not losing your mind, try threading a M10x1.0 brake line fitting into the sender port and see if it threads in all the way.

The later senders went into an adapter fitting at the rear of the main oil gallery, which was screwed into the fitting for the Carrera Tensioners. VDO aftermarket has a few with tapered thread so it is possible you got the wrong one, unless it's a Porsche box with the red letters on the plastic, in which case I'm stumped.

[304065]

check the part number here:
http://usa.vdo.com/products_solution...ssure-senders/