Water pump not clearing injection pump

[98HMC4]

Hey all,


In the process of installing my p400. Got my injection pump in and went to install the water pump when i noticed it didn't seem to fit up right, luckily i was paying enough attention to see this.
I already had my other 6.5 disassembled so i was unable to check clearances.

Basically the cover has a tab, its pressing against or coming into contact with the injection pump stud and nutt that sticks into the timing component area, Because of this its leaving a gap up top on the water pump plate / timing cover plate.
I did not torque it down or even install bolts up top because as i was setting it against the truck to seat the gasket i noticed this issue.

Has anyone else seen this? is this normal? my only guess would be maybe the tab keeps the nut from backing off? i would think this would cause some weird friction right there and make problems. but thats why I'm asking, looking for any knowledge here.




Thanks in advance,
-J

 

[EWC]

Isn't there a plunger and spring that slides into the injection pump shaft ?

 

[1994ch]

Is it a DB2 IP? if so that tab is supposed to hold the plunger and spring in that EWC asked about. Don't think the DS4 has the plunger so if it is in the way you could probably bend the tab back a little bit.

 

[98HMC4]

Its a ds4 - probably should have mentioned that.
pump looks identical to previous true stanadyne pump that came on the truck, so I'm not convinced thats the problem.

Maybe it is just a matter of bending the tab?

 

[WarWagon]

Something different here I haven't seen before on the IP. The IP (DB2 DS4) is normally held in by 3 bolts. Why does yours have a stud and nut as well? The standard timing cover isn't going to work with that setup. If this is a P400 and new design IP you may need a timing cover specific to it.

Minus the plunger and spring a typical 6.2/6.5 looks like this:

 

[Paveltolz]

Congratulations on the P-400 aquisition.
Hope this helps some. I'm in the middle of replacing the waterpump on my 99 Burb. So, to see what's what, I threw the water pump plate on without the gasket (or water pump for that matter).
Results: It looks tight and the reflections in my picture of the plate's back side make it look like there's contact with the tab and the pump but...I can get .45mm feeler gauge in between the two without contact and, again, that is without the gasket between the plate and the engine cover.

Stanadyne DS4...


Tab on the back of the water pump plate. Your tab is correctly oriented. Mine has some POR 15 on it from the slop job I did. Makes it look like it too has been in contact with the IP's center nut but, nope, just an optical illusion.
Not sure what the tab's purpose is other than to keep the Oil Fill tube or the rubber grommet from getting inserted too far and making contact with the IP.


Waterpump plate bolted up without the gasket between it and the engine cover.


.45mm feeler gauge inserted between the tab and IP nut. I couldn't take the picture and bend it back against the IP nut to show the thing vertical between the tab and nut. You'll just have to trust me on this...feeler gauge slide easily without contact between the two.


I would either bolt it up and measure the clearance or, measure the thickness of the timing gear cover on your old motor and the P-400. If there's an obvious difference then get on the horn to GEP to see what's going on.

Best wishes. Now to take the plate off and get back to my other side project....

 

[Will L.]

Only purpose of that tab is for db2 pin. With ds4 just make sure is doesn't hit the ip shaft nut.

 

[98HMC4]

I was able to find about a .007 difference between the timing covers themselves. I massaged the tab a little and gave it a few more tries but wasn't ever able to get it to fit.

After confirming the tab was only for DB2, i removed the tab. I have pictures of how i measured, etc. but my camera is in the work area currently.

paveltolz, i appreciate your pictures and confirming that my hard parts are indeed assembled correctly. all this information helps and hopefully will help others. The hummers don't use a gasket there to my knowledge, all i have seen have been an anaerobic sealant or gasket type compound (Permatex, etc)

Will, Thanks for the info as always

 

[Paveltolz]

Happy to help. The water pump, fan and clutch set up I bought contained a full gasket kit (two different water pumps, plate, T-Stat Housing to Heads & Crankshaft Oil Seal) and, your observation of no gasket is consistent with shop manuals I've seen. Probably will save me a lot of aggravation when I go to reassemble later as well. Thank you for that.