SHORT OF SUCK - G Wagen - vacuum weak

[Robert Dubsky]

20 year old/young G wagen short of vacuum to support brakes, cold start, engine off, and automatic kick down. I have to manually stop the engine, and automatic change down is at increasingly high revs. Hose system has been replaced. Any ideas on what to do next, please?

 

[fuzzer]

SHORT OF SUCK

I have a friend selling a Gwagen  if you are are interested , maybe for spare parts or somthing , maybe a second one .....

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=1744238132

(Edited by fuzzer at 10:41 am on June 27, 2002)

 

[Arnie]

SHORT OF SUCK

Hi,

I've had a similar problem with one G-wagen. The culprit was, however, a torn diaphragm in the servo booster (letting the vacuum escape). Dismantled it but not repairable.

If that's the case, you'll need a new booster drum. It's not worth risking a S/H one unless you can test it first, because it may also be knackered. Cost about £150 new.

As you mentioned "engine-off", is your vehicle a diesel? In which case the vacuum comes from a small pump rather that the intake manifold. Remove the nylon pipe and check with your finger (careful about the fan blades) if the pump produces a vacuum.

You might also want to disconnect various vacuum pipes from the syetm and close them off one-by one to see if any other components might have a leak. That is, if after disconnecting and blocking the pipe to the brake servo, your switch off starts to work, then you'll know the brake servo has a leak. etc.

(Edited by Arnie at 12:19 pm on June 27, 2002)

 

[Robert Dubsky]

SHORT OF SUCK

Hi!
I should have said - it is diesel.
I'll try those suggestions.
Many thanks
Robert

 

[Andy]

SHORT OF SUCK

Hi

You should check the vacuum to the diesel pump. There is a plastic diapharm on the top of the pump.You should see a vacuum pipe attached to it. Check the vacuum. Also check the vacuum diaphram for leaks. If leaking replace. If ok, then trace the vacuum pipe back and find the leak.

Regards

Andy @ www.mercedesservicing.com

 

[Robert Dubsky]

SHORT OF SUCK

Hi Andy!

Thanks for the suggestions.

The weekend is coming!

Robert

 

['89 250TD]

testing brake servo vacuum pump

Hi, had a similar fault yesterday - brake pedal really hard to depress & engine not stopping with key. Checked vacuum valve as per Haynes & it seems OK. There seems to be no vacuum at the pump with the engine running - does this definitely mean the pump is shot or is there some other test to determine this? Also, is there some way I can test if the servo itself is faulty now?
Assuming it's the pump - how simple is it to replace/repair - Haynes manual says fan needs to be removed & special Merc tool is needed for this - anyone know if this is necessary?

Thanks, Mark

Hi,

I've had a similar problem with one G-wagen. The culprit was, however, a torn diaphragm in the servo booster (letting the vacuum escape). Dismantled it but not repairable.

If that's the case, you'll need a new booster drum. It's not worth risking a S/H one unless you can test it first, because it may also be knackered. Cost about £150 new.

As you mentioned "engine-off", is your vehicle a diesel? In which case the vacuum comes from a small pump rather that the intake manifold. Remove the nylon pipe and check with your finger (careful about the fan blades) if the pump produces a vacuum.

You might also want to disconnect various vacuum pipes from the syetm and close them off one-by one to see if any other components might have a leak. That is, if after disconnecting and blocking the pipe to the brake servo, your switch off starts to work, then you'll know the brake servo has a leak. etc.

(Edited by Arnie at 12:19 pm on June 27, 2002)

 

[g-class merv]

Are you still a fellow G owner?
Regards,
Merv!