Hey, everybody-has this come up before?? - PeachParts Mercedes-Benz Forum

C Sean Watts · #1 11-03-2009, 01:54 PM

Electric vacuum pump.

Fab up a lil' block off plate and never worry about the bearings going crazy and ruining your day.

I asked if the "psi" in the description is actually inches of Hg, so don't burn the guy too hard.

If most of our vac. pumps top out at 19" we just might be able to work with something like this.

Jeremy5848 · #2 11-03-2009, 02:10 PM

Might work for awhile but since the pump would have to run continuously, I'm not sure how long it would last.

C Sean Watts · #3 11-03-2009, 02:35 PM

Quote:

Originally Posted by Jeremy5848

Might work for awhile but since the pump would have to run continuously, I'm not sure how long it would last.

I did think about that. I would hope it would last as long as your average alternator.

leathermang · #4 11-03-2009, 02:43 PM

UH... why would it have to run continuously ?
Vacuum CAN be stored , then replenished when needed....

scottmcphee · #5 11-03-2009, 02:45 PM

Remove the electric motor from that thing, put a pulley on it and drive it from the fan belt. It would be more compact, running all the time, and is probably more efficient that using electricity from the alternator.

I asked the ebay vendor:
How many AMPS does it draw? What is the rated duty cycle / can it run continuously? And is the motor a brushed or brushless design?

Jeremy5848 · #6 11-03-2009, 03:19 PM

Quote:

Originally Posted by leathermang

UH... why would it have to run continuously ?
Vacuum CAN be stored , then replenished when needed....

The eBay product is specifically designed for power brake boosters that "consume vacuum" only when the brakes are actually used, meaning not very often for most folks who don't ride their brakes. Our diesels, however, use vacuum for all sorts of things and the vacuum pump is continuously active. All you have to do is have a vacuum gauge on one of the lines and push on the throttle or operate an ACC button or door lock to see it in action. It would be interesting to put a flow gauge in series with the main vacuum line to measure the amount of air that the vacuum pump has to pull out of the various vacuum-using components.

W124 and W126 and W210 (and other models?) have an electric vacuum/pressure pump for the door locks and pneumatic seats; those pumps run only when the locks are actuated. The W123 uses its engine vacuum pump for everything.

Maybe it's not as bad as I am thinking but it definitely is a lot more than just occasional power brake operation. That's why I suspect that the electric vacuum pump offered by the eBay seller is not rated for continuous duty.

OTOH, I would like someone other than me to try one and see what happens. I would be happy to be proved wrong, just not on one of my cars, please.

Jeremy

compu_85 · #7 11-03-2009, 03:26 PM

I think that older ford diesel pickups use an electrical vac pump. I think VW 1.8ts use them as well. It would be simple enough to add a pressure switch which turns the pump off when it's not needed.

-Jason

Les Jenkins · #8 11-03-2009, 04:57 PM

The pump must be continuously running. The Vacuum Control Valve on the injection pump is a controlled leak and is always leaking, more so with heavier throttle usage.

scottmcphee · #9 11-04-2009, 02:54 PM

The vendor couldn't answer any of my questions by the way.

Considering vacuum is critical for braking, and very necessary for good transmission shifts, putting some aftermarket pump on must be a very reliable part.

All the other fub dubbery vacuumy controlly things, locking, and headrests for gosh sakes... who cares if those "fail" at highway speed. But when I go to use brakes, and like down a mountain pass... they better be there!

#10 11-04-2009, 03:31 PM

What are you trying to accomplish by removing it?

Whiskeydan · #11 11-04-2009, 06:05 PM

Quote:

Originally Posted by LarryBible

What are you trying to accomplish by removing it?

Exactly? I've seen stock pumps with 300K+ miles. How many would one expect to chenge during the life of the vehicle?

Les Jenkins · #12 11-04-2009, 09:23 PM

Considering the pump has done around 500 million pumping cycles at 200k miles (one per crank rotation), I'd consider it a pretty darn reliable piece of equipment.

No wiring, no noise, no vibration, no maintenance, autonomous operation and its mounted out of the way on the engine instead of taking up engine bay space.

If I were going to eliminate the stock vacuum pump, I'd eliminate vacuum entirely. Hydroboost brakes, electric door locks and solenoid ACC actuators. The transmission modulator would be the biggest issue, though a manual transmission will solve that.

C Sean Watts · #13 11-04-2009, 10:51 PM

from the aspect of seeing other vehicles (mostly trucks) and military spec. Hummers that use either something like this or a positive pressure pump system (but not the air brake compressor.) There was a thread about a year ago about the ball bearings going in a vac. pump but fortunately no major damage. Counting that post, I know of three of pumps going bad. The other two owners I spoke to, and both had major damage.

mplafleur · #14 11-04-2009, 11:17 PM

The SD I currently drive, I bought with a broken cam and timing chain. The root cause was the vacuum pump bearing busting out.

compress ignite · #15 11-05-2009, 02:07 AM

Electric Vehicles
Some '80 series Turbo Volvos

I'd thought I'd found the Holy Grail...
with the OM606: Timing Cover,Timing Device and Vane Type Vacuum Pump...
BUT a 606 owner let me in on His Vacuum Pump Failure, no engine damage/
just inconvenience (AND cost).