My 80 300D has only 5in of vacuum with all lines blocked off. Is this normal?

No, I think it should be more like 18-22. I had the same problem on my '79 300 SD. Rather than replacing the vacuum pump, I bought the two different rebuild kits for the vacuum pump, and a new gasket for mounting it. If you do rebuild it, it is very self explanatory, once you take the pump apart. BE VERY OBSERVANT, when taking the covers off, slowly, because the diaphragms will fall off, and without a proper chassis manual it is a guessing game as to which direction they go back in. If you take really careful notes it is super simple.

Bill, don't feel you don't belong in a DIY forum. If you diagnose the problem, and that's the hard part to get right, you can then talk better to the techs.

Maybe DIY really stands for Diagnose It Yourself.

BCingU, Jim

Patsy ,

Thanks for the information. I rebuilt the vacuum pump with no problem and everything is worhing fine now.

hi
where can i get rebuild kits for the vacuum pump for a 300D 84, also i wnat to make sure that the vacuum pump you are talking about is the one mounted on the injector pump, thanks.

The 18-22in you refer to, what are the units on that (inches). I am wondering how I can check my vacum pump just to make sure it is working okay.
Thanks in advance folks.

Silverbullet, those would be inches of mercury.

Aymn, I have read your posts elsewhere, and this is the place to be as far as questions go for your '84 300D, there are many people here, who know alot about MB's. The 'thing' on top of the injectorpump, is definatly not the vacuum pump. Find the Power brake booster on the firewall, you will see a goodsized black plastic tubing going into it...follow this tubing towards the front of the car. At one point it attaches to metal tubing (you're getting warmer) follow the metal tubing down towards the front of the engine, you will see that there is a fitting that attaches to another part that is attached to the engine with a bunch of little bolts. That thing is the vacuum pump. I am curious as to exactly what vacuum line is plugged on your car, and where it leads to. You do not mention have a problem with your powerbrakes, so I think that your pump is probably ok. Tell us more, before you go out spending money. As far as the rough idle is concerned, go through some of the archives here and you will find a wealth of info.

-Larry

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09 Jetta TDI
1985 300D

Hi
Yes Larry I am trying to get info from everywhere because I new to diesel but I really like to fix things myself and I want to learn, so you might see a lot of silly questions, about which line is plugged currently the plastic adapter that goes to the center lock is disconnected and the + rubber distributor is plugged at the terminal that this adapter was supposed to go in, about the breaks it is not really ok, it needs some effort to press on it but still works but it is stiff compared to normal breaks, ok let me ask some silly questions
1- how can I check the vacuum pump (tools, procedure)
2-how can I get parts number to be able to order them
3- about the rough idle, I tried to adjust it as I red hear but the adjusting bolt just screw in and out without any Chang in the idle, do I have to Chang it and if so how can I do this, sorry for this long post but please pass the knowledge so I can do the same, thanks again.