Engine/Transmission (1994 - 1998) '97 vacuum pump gasket

[JPittinger]

I think I narrowed an oil leak down to the area at the front of the vacuum pump where it bolts to the back of the timing gear housing on my bone stock '97. I've never had a vacuum pump off before, so I'm wondering- Is it a gasket? an oring? What do I need to fix it?

Thanks a bunch, JJ

 

[Bob V]

It is a gasket, I had the same leak on my '97. I didn't remove any hoses for the PS, I was able to slide the vacuum/PS unit back enough to replace the gasket. Sorry no part # for the gasket

 

[JPittinger]

Thanks, Bob. I'll call the Cummins shop, tell 'em what I need, and give it a shot. Not removing PS hoses makes it sound more reasonable.

 

[Dave M]

I replaced the vacuum pump to gear case gasket on my 97. I just unbolted it and pulled it back. I believe I did it all from underneath. The problem was the pump gear was dripping oil and the oil from inside the case kept getting oil on my gasket. Since there is limited wiggle room and its hard to move or see what your doing, I had trouble keeping the gasket centered and line up the bolt holes while holding up the heavy vacuum/ps pump. Two people might be helpful here.



I kept having the gasket slip before it was on all the way... . geeez. It was a pain. I kept removing the gasket sealent and re-cleaning the gasket and gear case and pump but it was a losing battle. I finally just slapped it together. It still leaks. You might buy 2 gaskets in case you screw one up and pinch it. . Mine was a stiff gasket, like it had metal under the gasket.



I'm not saying it can't be done but , for me, it was a very frustrating experience. :{ Make sure there are no kids around to hear the colourfull language you may acquire. :-laf



Good luck,

Dave

 

[SKnapp]

I too have to do this gasket swap. what do you guy's think of puting some orange rtv on it ?

 

[JPittinger]

SK- Funny you say that... The reason I'm fixing mine is that the orange RTV that some retard before me put on leaks like it wasn't even there. I paid about $7 at the Dodge dealer today for the gasket, had it in stock too.



The gasket has a bump (sorta like an imbedded oring) on one side; does it matter which way it goes?



Thanks again, JJ

 

[CumminsPower98]

I personally have not had good luck with these gaskets. I have never replaced mine though, I have always just used a little black RTV on both sides. This last time it leaked again so I pulled it all out since I had to replace the big o-ring between the tow vacuum pump halves anyway and I made my own gasket using the OE as a pattern. So far it's holding. The OE gasket has a slick surface so I'm thinking the silicone was having a hard time sticking even when cleaned good. I tried a new gasket on a '97 and it wasn't long and it was leaking. I sure wish they would have made the vacuum pump like the injection pump with a big o-ring.



JPittinger, I don't think it matters which way you put it on.

 

[Dave M]

I believe you are right about the OEM gasket being too slick for RTV sealant to stick. The oil on everything does not help matters either. I like the idea of making a pattern on paper gasket material from the old gasket and trying RTV on that.



I was wondering about where the bump on the gasket went too.



It would help though, if you had three 6 foot skinny arms and fetus sized hands with the strength of a gorilla :-laf and eyes on the ends of your fingers to see behind everything. Then I think it would be a piece of cake.

 

[Bill Lins]

I used Permatex on both sides of the gasket- no leaks.

 

[Dave M]

I used Permatex on both sides of the gasket- no leaks.

What kind of Permatex?

 

[GAmes]

Mine also leaked and I found that the bolt to the L bracket near the center of the assy was sheared off in the block. I think the weight of the pumps caused the gear housing to bend enough to leak. When I replaced the gasket I also installed a #8 grade bolt (don't remember the size). Hasn't leaked since.

 

[Bill Lins]

The nasty brownish-black non-hardening stuff. (Never can remember if it's #1 or #2).

 

[Nate]

IIRC that gasket comes with the vac pump seal kit from Cummins, which is about $8.