temporary air pump removal M103 - plug?
 

Hi all
The air pump on my 1992 300TE (145kmiles) is about to seize, it continuously makes a terrible ginding noise, even after the engine has warmed up. Disconneting it did not help. In previous posts I found that the pump may be removed (till the rebuilt one arrives) and a shorter belt (from a 260E) can be installed to compensate for it's lack. However I have not found any hints how to plug the resulting holes in the manifold or wherever the pump's hoses conect to. Are there some dealer parts available (part numbers)? Or has one of you experienced with custom made plugs? Or is schewing gum just fine? :) Your sensible input is highly appreciated. Have a nice day, Bruno

None of the air passages from the pump are open til there is vac applied to the switch over valve and air shut off valve..
..so, just put a BB in the vac feed line to the air shut off valve and nothing will open...
If you have Cal version , you will trip a CE air code , but that can be cleared after pump is fixed..

My experience with the MB version is nil, but from other brands experience says that the most common reason for pump failure is VALVE failure - i.e. hot gases backflowing through the pump. Check the valve - whether a check valve or vacuum-operated - before leaving the pump outlet port hose hanging free.

Steve

Yes , do check that you do not have pressure after unhooking,, kinda goes without saying..

I have never seen that cuz your chassis Benz has a check valve beyond the vac air valve, so both would have to be bad..
The main problem with this unit is a bad front bearing.. very common on this pump..

Many thanks for your thoughtful comments! Bad bearing is about how it sounds. I guess I may even forget to install a rebuilt one.
Have a nice day, Bruno

I bought my car with bent air pump pulley. Bearing broke,pulley sliped off and bent causing belt to slip and tear in pieces. I went to search online and found ney pulley with bearing for like $100. Same company sells bearings only for like $30 but I didnt want to compress bearing into bent pulley. Good luck

I have successfully removed the pump and installed a shorter belt. I plugged the rubber hose witha rubber plug. Everthing works fine. Special thanks to John who has reported the correct size belt that is needed after the pump is removed (2365 mm long, see following thread:

http://www.peachparts.com/shopforum/tech-help/84952-m103-air-pump-serp-belt-help-needed.html?highlight=napa+belt+air+pump). A belt from an earlier M103 without airpump has a different length.
Bruno