616 Vac pump- swap - PeachParts Mercedes-Benz Forum

240D.Bill · #1 10-26-2020, 02:13 AM

Can I swap out my diaphragm pump for the piston style? I’m going to look at used parts in a day or so. I don’t have a preference personally but I’ll take what I can. One less hose Under the hood sounds good. The bell housing and pump armature look the same.

Diesel911 · #2 10-26-2020, 12:10 PM

Quote:

Originally Posted by 240D.Bill

Can I swap out my diaphragm pump for the piston style? I’m going to look at used parts in a day or so. I don’t have a preference personally but I’ll take what I can. One less hose Under the hood sounds good. The bell housing and pump armature look the same.

I can't say what years are involved but I have seen diagrams in the Manual that show some central timer bolts that hold the timer to the intermediate shaft are drilled through to squirt oil out of and others are not.

I have no idea if that is significant when it comes to swapping types of vacuum pumps.

The attached diagram shows a drilled bolt. But, I did not note what engine or year the diagram represents.

resago2000 · #3 10-26-2020, 01:03 PM

you could delete it and just use an electric vacuum pump in the lower left hand corner. very clean install. I'm guessing you don't need vacuum for the trans, so its an easy mod.

240D.Bill · #4 10-26-2020, 11:39 PM

Thanks, I’ve considered that but I greatly appreciate the minimal dependence for electricity on this model.
I installed a new vacuum pump today. It works great for the fuel shut off but I have to pull like mad between stoplights.

240D.Bill · #5 10-26-2020, 11:42 PM

Thanks! Needs more investigation. $300 for a new one isn’t so bad but it would seem they don’t sell the diaphragm style any longer.

resago2000 · #6 10-27-2020, 10:55 AM

I have my fuel shutoff using manifold vacuum.
since I deleted my vacuum pump, my shutoff and other accessories use manifold vacuum, hooked up where the vacuum pump used to exhaust into the intake.
my electric vacuum pump just powers my brakes.

this of course only works if you have the butterfly flap in the front so vacuum exists.

check the link in my sig for pictures.

240D.Bill · #7 10-27-2020, 06:49 PM

Quote:

Originally Posted by resago2000

I have my fuel shutoff using manifold vacuum.
since I deleted my vacuum pump, my shutoff and other accessories use manifold vacuum, hooked up where the vacuum pump used to exhaust into the intake.
my electric vacuum pump just powers my brakes.

this of course only works if you have the butterfly flap in the front so vacuum exists.

check the link in my sig for pictures.

I‘d love to see the pictures but don’t see the link. Also I’m not sure what you mean by ‘butterfly flap’.

resago2000 · #8 10-27-2020, 06:54 PM

butterfly = throttle plate. I have a pneumatic IP.

https://photos.app.goo.gl/AdP7i8xfCJeFuk5y9

240D.Bill · #9 10-27-2020, 06:54 PM

Found your google link pics on your public profile. Thanks.

NZScott · #10 10-28-2020, 01:44 AM

FWIW, people might end up doing the opposite swap shortly - there's been a shortage of rebuild kits/ parts for the piston type, yet the diaphragm ones apparently are still available.
I have the outlet hose onm one of my vacuum pump equipped engines just venting to atmosphere with a upside down U pipe if you don't like the 2nd hose.

240D.Bill · #11 10-28-2020, 03:32 AM

I'm not concerned about the hoses. I just want a good pump and I'll look for a diaphragm pump if parts aren't available for the pistons. i appreciate the tip. thanks

240D.Bill · #12 10-30-2020, 01:07 AM

Quote:

Originally Posted by NZScott

FWIW, people might end up doing the opposite swap shortly - there's been a shortage of rebuild kits/ parts for the piston type, yet the diaphragm ones apparently are still available.
I have the outlet hose onm one of my vacuum pump equipped engines just venting to atmosphere with a upside down U pipe if you don't like the 2nd hose.

I just read in "Removal of the Intermediate Gear Shaft" (05-412 of the FSM) that "Types 123.102/103/105/125/130 as well as types 123.183/190..." were fitted with a modified timing device, shaft, and hollow bolt were also fitted with a double diaphragm pump which received pressurized vs. splash lube oil via the shaft and bolt. These versions must not use the single diaphragm pump because of potential damage from hot oil to the diaphragm. It's unclear if this applies to the piston type. Im not familiar with the double d pump but it's suffice to say that a single diaphragm pump should not be used if you have a hollow bolt vs. the nut securing the timing device.

240D.Bill · #13 11-08-2020, 09:48 PM

Quote:

Originally Posted by Diesel911

I can't say what years are involved but I have seen diagrams in the Manual that show some central timer bolts that hold the timer to the intermediate shaft are drilled through to squirt oil out of and others are not.

I have no idea if that is significant when it comes to swapping types of vacuum pumps.

The attached diagram shows a drilled bolt. But, I did not note what engine or year the diagram represents.

As per the FSM- Every version of the shaft is hollow. The timing device end is plugged with a ball bearing on version 1 & 2. The double diaphragm pump was used for the big boats 123.125 & 123.128 and was lubricated by the unplugged shaft. You dont want that one squirting hot oil on the single rubber diaphragm.

240D.Bill · #14 11-08-2020, 09:55 PM

I dont think this would mount as pictured because the steering pump is in the way but if you ditched AC like i have the compressor mount may be an option. That is of course if you could even find one. I thought it was interesting because one of the threads was discussing pulley driven vs. oe vs. electic pumps options.

resago2000 · #15 11-09-2020, 10:11 AM

there are also alternators with vacuum pumps attached to the back.
you would have to mount it differently i think though.