Vacuum Pump Failure, picking up the pieces? - PeachParts Mercedes-Benz Forum

eightiessadies · #1 06-08-2014, 01:56 AM

Hello, I had a vacuum pump " explode" and I'm trying to figure out what I need to do before it's safe to try and start the car up again. If i need to take it to a professional. And if there is any literature regarding my specific predicament.

It's a 1983 240d 2 tank grease car conv. AT with a 1980 engine, the pump came with the engine and says pierburg mercedes. It is the piston type.

I was driving on the highway when the "veggie" filter clogged and I was losing power. Come to find out, I'm also low on diesel and the car was struggling for fuel. Moments later I lost vacuum, suddenly, hard brake, stuck in low gear, high rpms. I thought I'd keep driving a bit and try to make it home because I thought a vacuum line popped off or something. Especially since I had just had the master brake cylinder replaced....
Started getting a lot of smoke from tailpipe and engine overheating and not shifting up to high gear so I decided to stop. Tested for vacuum at the main line right after VP and got 2-3 hg. Decided to tow home.
Took off check valve and it seemed to be stuck, cleaned with wd40. Reinstalled,
Still no vacuum. Idle really poor, car trying to stall out, bit of clanging noise. But as I mentioned I ran out of fuel and probably had some air in the system so I don't know if the noise was just the rough idle from air making it's way through the lines.
So I removed the VP and it is toast. The wavy element (timing element?) that moves the VP piston looks OK, smooth, no visible wear, except on the outside of the round part of the assembly has a nick in it, possibly where pieces of the VP made their way through. There are shavings all inside the pump housing and in the oil pan.
I dropped the oil pan and found a few bits of the VP. I'm not sure if I've collected all of it, and if not what I can do to be sure all of the shrapnel is removed. I'm not very knowledgeable on engine internals....

So I'm looking for...........
-Written details about removing debris from engine esp. after late model VP disintegration
-VP installation tips ( i have the old one off and a new MB pump on order)
it seems that instructions are not readily available
-Is this not a good DIY project and should i take it to a really expensive mechanic who will take weeks and $1,000's to fix it

I can't seem to find anything completely covering this topic on this site
Help appreciated

MANY THANKS

eightiessadies · #2 06-08-2014, 02:03 AM

Timing chain still intact I think

Diesel911 · #3 06-08-2014, 03:21 AM

While you are waiting for the new Vacuum Pump you need to check the in and out play on the Timer 0.05 to 0.12mm for the timing unit.

In the pic you see the worn Intermediate Shaft Bearing/Bushing that can be one of the causes of Vacuum Pump Failure.

My question What in particular causes vacuum pump failure?
What in particular causes vacuum pump failure?

eightiessadies · #4 06-08-2014, 11:59 AM

After further reading, thanks for the links, I'm still wondering two things.
Does the timing chain need to be loosened to check for play in the timing unit,
And what tools are required to measure.

After seeing more pictures I realize I still haven't found any of the ball bearings, and about 1/3 of one of the bearing outer sleeves. They weren't in the oil pan or the pump, how can I find them?

eightiessadies · #5 06-08-2014, 12:06 PM

Except, I did drain the oil, maybe they all rolled out.
I'll strain it and see

vstech · #6 06-08-2014, 12:38 PM

Pull the lower oil pan, and inspect BOTH the pan and the oil pump pickup! Also look up into the engine for debris.

Diesel911 · #7 06-08-2014, 12:46 PM

Quote:

Originally Posted by eightiessadies

After further reading, thanks for the links, I'm still wondering two things.
Does the timing chain need to be loosened to check for play in the timing unit,
And what tools are required to measure.

After seeing more pictures I realize I still haven't found any of the ball bearings, and about 1/3 of one of the bearing outer sleeves. They weren't in the oil pan or the pump, how can I find them?

Since I have not done that job before I sould give that a generic Yes.

Because if there is no Tension on the Timing Chain you can be sure the end play reading is correct.

I say that because in order to know if the Timing Chain can make the measurement incorrect would be to take 2 measuerments. One measuerment with the Timing Chain as is and then remove the Tension and check it again.

So far I have not read of anyone taking both measuerments.

Diesel911 · #8 06-08-2014, 12:54 PM

Line up the Camshaft Bearing Tower Timing marks extremely accurately with the Timing Mark on the back of the Camshaft Gear and look down and look at the degree marks on the Crank and see what they are.

eightiessadies · #9 06-08-2014, 05:26 PM

Well this is proving a bit out of my league as I don't really
Know anything about timing and cams. I'm about confident enough to install a vacuum pump. It won't hurt to try and figure this out but I may be towing it some where.
Looking up into the oil pump on a Baltimore street without any jack stands.....

I did strain my oil and nothing but metal shavings, which is probably bad.
I did change the oil very recently around the same time I started losing vacuum
I don't suppose the pump would have supplied vacuum for ten days of driving with no bearings though. Wishful thinking that they rolled out with the last batch of oil.

Just eyeballing the cam next to a tappet set it looks like 0.3 to 0.5 mm of front to back play. I believe 0.05 to 0.12 is spec?
I'll have to get a real tool for that.

Thanks for the help!

eightiessadies · #10 06-08-2014, 06:22 PM

Found 10 ball bearings and the rest if the bearing races in the oil pickup.
The screen is in good shape.

Doug306 · #11 06-09-2014, 02:08 PM

I did a piece on a somewhat similar project for a '95 E300. At the bottom is a link to a lot of pictures. It's not a really hard job. Good luck.

'95 E300 Vacuum Pump Cam Replacement Project

eightiessadies · #12 06-09-2014, 07:28 PM

Very helpful pictorial Doug, thanks! I think my ITD is Ok at least the roller cam part looks more like your new one than the old one, smooth, no grooves. My main concern was front to back play of the " intermediate shaft" if I have the terminology right.
Spec is 0.05 to 0.12 mm and I figure I have 0.39mm.
You didn't replace the brass bushing on that shaft did you?

I wonder how my roller coaster part survived? Seems impossible with the VP damage. It looks like other than the bearings which went to the oil pan, all the parts of the VP stayed stuck towards the front. Could this mean the VP piston seized and held out of the way and it wasn't destroyed by the
ITD?

I think I would be crazy to try to replace the intermediate shaft bushing w/o having a garage or half the tools I need and only evenings to work.
So I can either
Install the new VP, fill up the oil and see where I'm at.

Tow to a garage and have them asses the ITD

Any thoughts? Professional or amateur advice appreciated

I did turn the engine CW with the PSP, which I've never done before. There were no snags
But a cyclical easy, harder, easy, harder. This is normal right?

Doug306 · #13 06-10-2014, 09:52 AM

You're welcome! If your ITD surface is smooth then I would just replace the VP. I had longitudinal play on the ITD too. I didn't measure it but it just floats on the IP shaft. The bushing/sprocket/VP Race come as one piece on my car. For the tolerances to increase like that you would need wear on the ends of the bushing. I just looked at my old one and have no obvious wear. Get a professional opinion before you decide whether to change the ITD/bushing. Make sure you prelube the new VP before starting the engine. I would recommend using a 100% synthetic oil too, if you are not.

For whatever reason your ITD wasn't damaged, it's a good thing. Your job is about 10% of what mine was.

You should only turn the engine in a CW direction using the crankshaft as looking at it from the front. I'm 99.999% sure that applies to your engine as well.

Stevo · #14 06-10-2014, 10:54 AM

[QUOTE=eightiessadies;3340464]After further reading, thanks for the links, I'm still wondering two things.
Does the timing chain need to be loosened to check for play in the timing unit,
And what tools are required to measure.

The timing chain doesn't need to be slacked or removed to check the lateral play of the timing devise. Just grab hold of it and give it a push and pull. Mine, which is actually pictured in post #3 had 2.5 mms of play, when it took out the VP. Now when ever I have a V/P off I give that timing device a quick "push pull" check.

eightiessadies · #15 06-10-2014, 01:06 PM

I'm thinking as the ITD play is not in the whole mm range. And the pump is fairly easy to remove. I'll try and get my car on the road. And check the VP and ITD in a week. Then a month. Maybe drive it to a shop and have them check it out.

To switch to synthetic oil I just need the oil fully drained like it is now right? I had rottella on it.

Does the VP gasket need any special goop?
How about the oil pan gasket that I'm replacing?

I can look those things up pretty easy though.

Thanks for sharing. It's been a help!