TR Major - Vacuum pump o-ring

Looked closely at my parts manual & spottted an o-ring that was not in my TR upon disassembly. Presumably, the previous tech 'forgot' this seal. Aaaarrrggghhhh!!!

It appears to fit over and around the vacuum pump shaft and into the groove immediately behind the splines and seal against the ID of the cam. In this position, the o-ring would be in a fairly static location as both the cam & pump rotates.

As an alternative, this o-ring could be intended to seal further back on the vacuum pump shaft - around the shaft, but wedged between the face of the cam's end and the body of the vacuum pump. I doubt this - since the o-ring would rotationally 'slide' during operation.

Can somebody please confirm - where does Fcar intend for this o-ring to seal?

Thanks in advance,
Vince
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It is a TINY TINY TINY little thing... 105661. How it is fitted exactly, I cannot tell you -- and I'll be the first to admit it. If 91TR or Dave Helms is around today, they'll know for 100% sure.

Position #64 here:
http://www.ricambiamerica.com/article_info.php?articles_id=2844

I can pop one into an airmail envelope if you're not in a super huge major mega mondo rush, just let me know.

When we pack our 30K kits, I always worry that people won't even see that little bugger in it's poly-bag. It is about 1/2 the size of a cam-bolt o-ring.

 

Thanks Daniel - I do have a small o-ring in my kit (about 1/4" ID) but it has no PN on it. The ring's cross section seems pretty small for the 'groove' location immediately behind the spline. That is what is making me question its intended location.

I had sourced the kit more than a year ago from a 'competitor' of yours - hopefully Ricambi puts PNs an all the gaskets.

Thanks very much for the offer!

Rgds,
Vince

 

It sits in the groove of the pump shaft. It's job is to keep oil pressure in the camshaft, as the cam is hollow and the pump shaft is what seals the end of cam.

 

Thanks for the confirmation Brian!

Sure glad I spotted that o-ring in the parts book.
I'd have been scratching my head over a leftover o-ring... always a bad sign!

Thanks,
Vince

 

We do. We're at about 90% completion on this kind of labeling -- some things still go out with handwritten labels and some things have the original Ferrari stickers still on them -- but most things look like this (see below) and its one reason service kits take a bit longer to build. We think the little extra touches are really useful for DIY owners, who might not know simply by looking at a gasket what the p/n is. Shops like this method because stuff stays clean on the workbench and doesn't get all scattered about.

If we had more real-estate on the labels themselves, we'd include the product name. I think the p/n is good start, because you can always x-ref the number on our site against the exploded parts diagrams.

-Daniel
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Daniel -

The PNs are hightly appreciated. AND the parts diagrams on the WWW!

By the way... does Ricambi supply viton or buna-n o-rings?

Rgds,
Vince

 

It depends on the specific application. O-rings, seals, gaskets, etc. all come direct from Ferrari -- so I suppose it is whatever they spec, per part number.

Most, I think are actually Viton.

 

Daniel - surprised to hear that you buy all your stuff from the Fcar pimp. Your margins must be pretty tight!
Thanks again for the service.
Rgds,
Vince

 

A couple of pictures from one that broke.
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Thanks for the photo - I'll do a visual check for any apparent cracking in that area.

Apparently the pump:
~ is oiled by way of camshaft oil pressure running into the pump via the splined shaft.
~ oil flow is significantly restricted via the tight interface between the pump impeller and front face plate.
~ fills with oil to the level of the drain hole that is shown clearly in face of the broken pump.

Presumably then, the pump should be filled with oil up to that level prior to installation.

Do you folks bother with this step - or just let the oil pressure slowly fill the pump?

Thanks for the experience,
Vince