Vacuum Pump Rebuild? 1983 300CD
 

Just got an 83 300CD Turbo Diesel and I want to go thru it and do the obvious such as belts, hoses, alternator and some other things to insure reliability over the long term. Motor seems in very good condition and starts well at 0 degrees. The question is should I rebuild the vacuum pump while I have the front of the engine apart for all these other things..Mileage on the motor is unknown but I have heard that vacuum pump failure is catastrophic on this engine. Thanks

I'm from the "if it ain't broke, don't fix it" school myself...

"that vacuum pump failure is catastrophic on this engine."

If that is true I would sure rebuild it... the type I have on car is not that way... and it gave way within two months of me getting the car...
When I get a car new to me I change all the fluids, belts, etc.. and I would sure sleep better knowing it had been ' maintained' .....

The vacuum pump can fail in different ways. A failure which merely prevents the pump from producing vacuum (such as the failure of a check valve) is hardly catastrophic. Most likely the catastrophic failure that you have heard about is associated with a failure of the rocker arm bearing, followed by the small ball bearings being ingested by the engine. If this is what you are trying to prevent, you must replace the rocker arm, not just do a "typical" rebuild, which consists of replacing the internal check valves, piston sleeve and seals.

I could sure be wrong here, but wouldn't a pump with bad bearings make some weird noises before catastrophic failure. I always check out the bearings when ever I have one off but I wouldn't change it just as a "preventave" maintinance job, I donno, maybe one should???

Diesels make so much noise normally you may not hear the sounds of a bearing going out.....that is assuming it makes any.

iI just had the pleasure of rebuilding my entire vacuum system. For some reason every thing made from rubber on my car has rotted away.

The last thing I did was rebuild the vacuum pump. This is because it was making vacuum but just not enough. Now that I know what is inside the next time I do it its going to be a 20 min job.
If you run out of vacuum after a couple of pumps of the break or you car takes a while to turn off all I recommend replacing are the little valves that can be accessed by removing the screws on the front of the vacuum pump. Besides these valves the only other thing that comes with the pump rebuild kit is the piston ring and seal.
I can’t see how that could go bad considering mine looked like new, and to replace this you have to remove the vacuum pump from the engine. This is a real pain in the ***.

I don't have a lot to add, but I did want to say I agree with Tangofox007 that rebuilding with a new rocker assembly will cost $250. The rocker assembly is the part with the ball bearings that could come apart and wreck your engine. Since this is only about a 1" diameter bearing, I doubt it would make much noise before it destructs....you probably wouldn't know it was failing until it was too late.

I think your intentions are sound in trying to go through your new old vehicle and replace things that may cause you unreliability, but I am of the opinion that with 15 or 20 thousand parts on the car, you just aren't going to be able to check/repair/replace everything. There are literally hundreds of things that could break tomorrow and stop you cold.

My philosophy is repair the obvious things and drive it. The car will let you know what needs to be fixed in time. Face up to it, you have purchased a used car and until you develop some history you are flying blind.

My $.02 worth. Good luck!