Put a filter on shut off vacuum line - PeachParts Mercedes-Benz Forum

kerry · #1 01-18-2010, 12:01 PM

I recently discovered that despite the fact that the engine shuts down fine the shut off diaphragm was leaking oil. It has made me think we should put a clear filter in our brown shut off vacuum lines so that oil leaks into the vacuum system are visible. I had assumed that a diaphragm with a hole in it would manifest with poor/no shutdown so oil leaks would be readily detected. Apparently not so.
I haven't found an appropriate filter to go in the line but I will look for one when I next visit an auto parts store.

Diesel911 · #2 01-18-2010, 12:20 PM

Or, you could put the couple dollars a filter would cost towards the cost of a new Vacuum Shutoff.

Does the Vacuum Shutoff hold Vacuum?

kerry · #3 01-18-2010, 12:23 PM

I'm going to replace the shut off valve. I'm talking about putting filters in that line as a general principle on these vehicles.

When I pulled a vacuum on the shut off valve, it just sucked oil.

whunter · #4 01-18-2010, 12:50 PM

Quote:

Originally Posted by kerry

I'm going to replace the shut off valve. I'm talking about putting filters in that line as a general principle on these vehicles.

When I pulled a vacuum on the shut off valve, it just sucked oil.

"Hens tooth" 1985 300D vacuum filter dark black
"Hens tooth" 1985 300D vacuum filter dark black

Have a great day

kerry · #5 01-18-2010, 01:14 PM

I couldn't find clear small fuel filters at the auto parts store but found a clear 1/4" lawn mower gas filter at the hardware store. With a little dish soap in the hose, I was able to force on a piece of vacuum tubing to each end which will also fit the brown vacuum tubing in the car.
The W116 300SD had no OE vacuum filters that I can see, unless a PO removed them, but the lines look original. Since it has the dual diaphragm vacuum pump with separate lines to the brakes and everything else, a person would also need a filter in the large brake vacuum hose to detect a failure in the pump vacuum diaphragm even if a filter was put in the 'everything else' line.

Cr from Texas · #6 01-18-2010, 01:22 PM

Quote:

Originally Posted by kerry

I couldn't find clear small fuel filters at the auto parts store but found a clear 1/4" lawn mower gas filter at the hardware store. With a little dish soap in the hose, I was able to force on a piece of vacuum tubing to each end which will also fit the brown vacuum tubing in the car.
The W116 300SD had no OE vacuum filters that I can see, unless a PO removed them, but the lines look original. Since it has the dual diaphragm vacuum pump with separate lines to the brakes and everything else, a person would also need a filter in the large brake vacuum hose to detect a failure in the pump vacuum diaphragm even if a filter was put in the 'everything else' line.

There are several threads on installing these clear fuel filters on vacuum lines. I have 3 on mine. Shutoff valve line, transmission line, and cabin vent line (just to reduce possible dust).

I would not put one on the large brake vacuum hose as it would become a restrictor and reduce vacuum to the brake system - not a good thing

kerry · #7 01-18-2010, 02:16 PM

I knew there had been other threads on this topic but I added this one because I was not previously aware that a shut off valve could leak oil profusely while still functioning perfectly fine. Hence, the need for the filter.

charmalu · #8 01-18-2010, 03:27 PM

Here is how I routed mine, just some cheap fuel filter I picked up for a buck.

Charlie

Stevo · #9 01-18-2010, 03:55 PM

Quote:

Originally Posted by charmalu

Here is how I routed mine, just some cheap fuel filter I picked up for a buck.

Charlie

Wish I could find some for even twice that price

MBeige · #10 01-18-2010, 04:49 PM

Quote:

Originally Posted by Stevo

Wish I could find some for even twice that price

Mercedes P/N 000 078 06 56

compress ignite · #11 01-18-2010, 04:52 PM

'85 SD,Vacuum ShutOff Diaphragm fails (Un-beknownst to me) Vacuum Pulls
Engine Oil up to:
'Not only the Vacuum portion of the Ignition Switch ,
BUT also the HVAC controls(And their Vacuum lines) behind the Console.

Big Greasy Mess
('Had to take apart and blow out with brake parts cleaner,EVERYTHING)

Unsolicited Advice to y'all:
'Get the little "See Through" filters VW uses and install one in the Vacuum
ShutOff Line.(See Charmalu's reply # 8 above)

Stevo · #12 01-18-2010, 05:48 PM

Quote:

Originally Posted by MBeige

Mercedes P/N 000 078 06 56

Thanks much, none of my searches turned that up

kerry · #13 01-18-2010, 05:51 PM

Ace Hardware. Briggs and Stratton filter $4.99.

Stevo · #14 01-18-2010, 05:59 PM

"Shucks" has them for $3.99, but Phil's price is around $1.50, forgot the exact price but I just ordered a dozen.

charmalu · #15 01-19-2010, 02:22 AM

I picked up those filters at a Good-Guys street rod show out in the swap meet.

In my first picture, the 3 way connector between the filter and the yellow check valve. It`s one from under the carpets for the door locks. I got rid of the spider connectors, this one makes it look real tiddy and clean.

Charlie