Do you drive a 1985 Mercedes 300d or are you familiar with them?

August 26, 2012 8:18 PM

Do you drive a 1985 Mercedes 300d or are you familiar with them? Do you know why my driver and front passenger seat belts are suddenly not engaging?

They driver side seat belt was a little bit loose in the buckle yesterday, but worked this morning. Later, a passenger and I got in the car and neither one would engage. I suspect it has something to do with the mythical vacuum system?

I will obviously be consulting my mechanic about this tomorrow, but if there is an at-home solution (that someone who is not very good at cars can handle) I would love to not have to drive around sans seatbelt.

Any help is greatly appreciated!

posted by justjess to Travel & Transportation (7 answers total)

No, the belts have nothing to do with the vacuum system. That's for the door locks. Maybe something fell into the mechanism. Try vacuuming out the receptacles with a crevice nozzle, or even some tubing taped to the nozzle's end. I doubt they're broken. I've had four of these cars and never had a problem--they're bulletproof. The fact that both latches are borked is kinda suspicious--anyone with chewing gum have it in for you?
posted by weapons-grade pandemonium at 10:22 PM on August 26, 2012

I don't know; we have a 1987 300 SDL, and anytime anything is funky with it, we go to the Peach Parts forums and see if someone there knows something. Those guys are amazing.
posted by linettasky at 10:29 PM on August 26, 2012

alt.auto.mercedes | Google Groups is also good.
posted by weapons-grade pandemonium at 10:35 PM on August 26, 2012

Phone the Mercedes dealer and ask the service dept. about lubrication. Sometimes they are very particular about what to use, if anything.
posted by weapons-grade pandemonium at 10:38 PM on August 26, 2012

My 300d was a bit older than yours ('79) but if it has been hot in your area something may have gone melty inside the buckle. I know parts of my mustard beaut were just so old they would start to ooze melty stuff. I would push the window button and whatever glue or maybe rubbery or plastic piece maybe was starting to disintergrate. Nothing major would break, but some sort of sealant or lubricant could be jamming things up.
posted by Swisstine at 10:57 PM on August 26, 2012

That usually means a coin has fallen into the buckle (stationary) part of the belt.
posted by gjc at 4:55 PM on August 27, 2012

Response by poster: For posterity: parts of the plastic border on the tip of the metal seatbelt (simultaneously) snapped off, causing the belt not to engage. My mechanic was able to figure out that jamming the seatbelt into the buckle in one swift motion engages it, and he's ordered me a new set.

Thanks everyone!
posted by justjess at 11:19 AM on August 28, 2012