Anyone know the bolt size for the vacuum pump body to case mount? Finally figured out what this major oil leak was. Thought it was the tappet cover all along but just noticed one of the mounting bolts for the vacuum pump to case mount was MIA ?‍♂️ not sure how after 290K miles a bolt randomly falls out

looks like: the top bolt is chrysler  05011421AA  (no description)  the bottom bolt is chrysler part number 04429637    M12x1.75px0.35

 

I am going to guess replacing the bolt isn’t going to fix your leak. Mine had a similar leak but all bolts intact, and it made a huge mess on the front of my engine as well as all down the drivers side block, it was the actual vacuum pump seal. I thought mine was the oil pan. Resealed my vacuum pump and leak fixed. If you do go this route make sure you put the oil feed line back on before you attempt to secure the pump back to the case. However I do hope that putting the single bolt back in solves your problem. The bolts are 15MM that hold the pump to your case, but can’t recall if fine or coarse thread. 

 

Seems like if only one bolt was in it , would be a good idea to pull it and put a new vac pump to timing case seal on it and look at the hole deal anyway

There`s a lot of rotational force from the power steering pump , and with one bolt, the only other thing supporting is the bracket from the lower bolt between the vac to steering pump to the block , I hear those crack sometimes with both bolts holding it on .There is a hub that insets into the timing case that would keep it from rotating to much, but that is probably not to good because the vac pump gear in the timing case is connecting the injection pump gear.

 

Good time to reseal the vac pump if its off and at least flush the steering system

 

I was going to reseal my vac pump and put on a new Borgson PSP  on last week , and had a vac seal kit handy , but when I pulled it apart the dogs on the vac pump drive gear were about 1/3 of the way cut thru and the drive coupler had some small cracks in it ,dogs on the steering pump were worn too , but not as bad , that's how much rotational force there is , 240k on the truck , I heard 4x4`s like to wear the dogs , and having any extra load on the front end makes it worse

I ended up getting a rebuilt vac pump from Gould Gear ,he has pics of the dogs snapping off completely ,that would leave you with no power steering and little brakes since its hydro boost .

He also sells the drive gear and coupler if you wanted- or find the need to rebuild it yourself

 

Hope you don't have anything but an oil leak

If you look in the 3rd pic in the moparman article link above , you can see  the top of the dog on the right and the bottom of the dog on the left are wearing at an angle from engaging into the cross drive coupler , the two edges of the dogs are parallel when new