Vacuum Pump

[KansasIDI]

In general, what part typically fails on the vacuum pumps? When I replaced the vac pump on my truck I'm pretty sure it was the original one, painted grey, with 300k and though weak it was still working/stopping things. I bought a Dorman about 8 years ago based on a member here saying the Dorman had the same casting marks as the Motorcraft units at that time and the pump has been solid since install. Is there any chance these premature failures are due to inadequate or wrong type of oil from factory? Worth removing factory fill and replacing it with something else?

And as a second thought, has anybody tried to add an electric vac pump to boost the overall vacuum? Could that cause a problem somehow?

I use a 99-04 vacuum pump for my HVAC, I have hydroboost brakes.

 

[Kizer]

what part typically fails on the vacuum pumps

In my experience, it’s usually been the diaphragm.

I have had, what seemed to be, a bearing failure on the Dorman brand pumps.
There are pictures on one of my “vacuum pump” posts.
I believe that those failures were largely due to the pumps having been shipped out (and installed) “dry”.

 

[IDIBRONCO]

Is there any chance these premature failures are due to inadequate or wrong type of oil from factory?

I think it would be from inadequate oil over the wrong type.

has anybody tried to add an electric vac pump to boost the overall vacuum? Could that cause a problem somehow?

I don't see how that could be a problem. While I don't know the specs, I believe that the electric pumps make enough vacuum in inches, they don't make enough volume of vacuum to work vacuum assist brakes for long.

I believe that those failures were largely due to the pumps having been shipped out (and installed) “dry”.

I agree.