2003 Sprinter low on power/brake booster not working

Hey everyone,

I’ve got a 2003 3500. Everything worked fine yesterday. Changed the fuel filter, and I think I must’ve somehow created a vacuum leak downstream from the vacuum pump. It feels like the brake booster isn’t working, and the engine runs like it’s in limp mode. Since the turbo actuator and the booster are both controlled by vacuum, I’m ASSUMING I have a vacuum leak. Both of these symptoms began simultaneously, from the first restart after the fuel filter change.

Am I on the right track here, thinking it’s a vacuum leak? I can’t see any visible damage to the vacuum lines, is there an easy, at home method to check for leaks?

Any help is greatly appreciated!

Eric Experience always recommends installing a gauge for troubleshooting.

The vacuum lines do have some history of deteriorating over time. You may have disturbed one or more during the filter change operation.

vic

The vacuum line also connects to the cabin heater recirculation solenoid, located above the battery. Could you possibly have disturbed it here? eg did you change the cabin air filter?

Keith.

Good point on attaching a vacuum gauge... I’ll try to figure out how to do that.

On my van, the battery, brake booster and fuel filter are all in the same area on the driver’s side (US, left side drive). This is the only area I worked in. It’s gotta be something around there, but I just can’t pinpoint it.

Thank you both for your input!

The vacuum system isn’t connected to the fuel system in any way on these older Sprinters, correct?

The vacuum system operates the turbo actuator. Check the brake booster vacuum line and the smaller lines to the turbo and recirculation control.

Motomofo1 said:

The vacuum system isn’t connected to the fuel system in any way on these older Sprinters, correct?

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Correct. As MWD already mentioned, on the earlier engines OM612 the turbo vane actuator is vacuum driven so charge air pressure can be affected.

Motomofo1 said:

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On my van, the battery, brake booster and fuel filter are all in the same area on the driver’s side (US, left side drive). This is the only area I worked in. It’s gotta be something around there, but I just can’t pinpoint it.
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Click to expand...

My OM647 has the brake booster hose and at least one cap plug. You should inspect for any open port.

The small hoses MWD mentioned feed up by the cabin air fan intake, and down under the cabin air filter box area, among other places.

A split or damaged hose near the fuel filter might not be that easy to see without removing the hose.

vic

The vacuum pump is located on the front of the engine near the fuel pump and very close to the fuel filter, could you have knocked a hose off here?

And sorry about the reference to the battery, I forgot it stays on the LH side on a NAS Sprinter whereas pretty much everything else swaps side Left to Right!

Keith.

Alright, I’m a big dummy! But I’ll post the results for anyone else who may encounter the same issue!

The line to the vacuum reservoir had pulled out. I was so focused on inspecting the lines in the general area where I’d been working in the first place, I didn’t really think about anything coming lose that far away. Problem solved! Thanks for everyone’s input!