I have a 300D, 1997. I have a break in the vaccum line that runs from the interior of the car to the driver side door and subsequently to the lock. I have located the vaccum line on the interior, it is just behind the hood release, and is visible through a little hole.

Before I skin all my knuckles and use language that my kids should not hear, does anybody have a trick to replace that hose, i.e. splice in replacement hose and thread it through the rubber connector from the car interior to the driver side door.

There must be a trick.

JCD

This may work - Take a black rubber hose that fits snugly on the vacuum tubing, cut the hose that you want to replace and put the black rubber hose on the old hose and the new. Go to where you want to pull it through to and start pulling. If I was going to do it I would more than likely actually glue the rubber to the vacuum line to insure it would not come off. Just make sure you have enough vacuum tubing to totally remove of the piece that had been glued. When you get the new tubing in place just "splice" the tubing together using the black rubber hose of the appropriate size. How do you know where the tubing is leaking at?

__________________
Jim

jcd:

Please don't try to take the kick panel cover off -- it is heat glued on and you will destroy it if you try to pull it off. We just wrecked both of them in my brother's 75 300D. Hard to get replacements, too. His were both water damaged and had cheap nasty speakers in them, but now we have none at all....!

Just where is the break in the line? Sam had one at the lock, along with a "repair" to the trunk lock that disabled the system. The usual failure on these systems is the diaphram in the lock actuator, not the line.

You can fix a broken plastic line with a short bit of rubber hose, no need to glue if it fits.

I can go look at the 75 (it's in my garage up on jack stands with the doors and fenders off!) to see what you are dealing with.

You may have to take the liner off the door -- details if you need them!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thanks for the help so far.

I know the lead is in/around the rubber "conduit" in the door frame because I can hear it leak when I open the door. Also if I attach a vaccum gauge to the vaccum hose and start the car with the door closed, it shows vaccum. If I open the door, I lose pressure.

Liner is off the door. This allowed me to test all three of the hoses to isolate the problem.

I also have rubber hose for "splicing. I issue is really the entry point of the vaccum hose. There appears to only be one small area to "intercept" the hose so I can splice in a replacement. It is behind the kick panel, left foot, drivers side. I can only see it though a small hole. It is at that point that the vaccum hose goes two directions, to the firewall and to the door. I just appears to be a near impossible place to insert a replacement.

Again thanks for your help.

JCD

jcd:

There are three lines to the driver's door: Supply, open, and close. The open and close lines have a "T": in them at the hole, the supply line is solid plastic there. You can dislodge the rubber boot on the door that encloses the lines, maybe you will be lucky and be able to splice it there. Sam's was broken about and inch and a half from the actuator. We pulled all the lines out of the doors and removed them, no breaks so far (knock wood)!

The line has probably fatigued in the rubber boot.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Peter,

You are exactly right. Here's some quick instruction. Also the Haynes manual is useful for the first 3 steps.

1. Remove drivers door panel.
2. Remove Kick Plate next to emergency break and hood release.
3. Remove floor mat and floor board/pad.
4. Remove plastic panel that covers the hoses.
5. Remove 3 way lock switch.
6. One at a time, remove each hose and check it for it's ability to hold pressure with a vaccum pump. In my case, the supply hose had a leak. The leak was in the rubber boot that contains the vaccum hoses and power supply for the electric windows.

Once the leak is isolated, in my case in the rubber boot, it can be repaired with rubber repair hose. The key is to remove each end of the rubber boot, i.e. from the door and from the door panel, to ease "fishing" hoses from the door to the interior. From there it is just a matter of patience and being firm with the hoses to make sure you do not break them.

If you need more specific instructions, reply to this thread or e-mail me and I'll be glad to walk you through it.

JCD

jcd:

We, um, kinda did just a little more dissasembly than that, actually.

The doors, fenders, interior except dash, and windows are out. We finished welding in a "home-made" rear fender tip last night, so will only need to fabricate some odds and ends around the taillights and the trunk floor to finish, then we can start paint prep.

A total resotration, in other words, which is why I could so easily check!

By the way, if anyone else is going to try this, get some trim adhesive -- the rubber boot is glued to the door and doorpost. Sam's will have to be replaced as they have died from old age.

Also, check the vacuum holding ability of the two vacuum tanks under the left front fender -- a small one at the top and a larger one beside the kick panel. The grommet that holds the hose into the tank can go bad, and the tanks themselves can leak. This means that you can lock the car just fine, but may not have vacuum to unlock it later. If the two little check valves are bad, get new generic ones at the auto parts store -- they are much cheaper than the MB parts and last just as long.

The kick plate is glued on, not screwed or snapped, and you must take care in removing it or it will be ruined. They may not be available new anymore.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Peter,

Thanks for the reply. Good luck in the restoration.

My next step is to check the tanks and the check valves. What appeared to be a total victory Sunday night turned out to be a partial victory as in about 2 hours, the door locking system is inoperable.

I did not find that the rubber boots on my 1977 were glued on, but your tip is a good one. I can't contemplate what it would be like to replace it. Fortunately, the rubber boot had not degraded, in fact it is in teriffic shape.

Who's Sam.

Take care and thanks for your help

JCD

jcd:

Sam is my brother.

And you have to separate the lines to replace the boot. That isn't why we took the doors off, though!

Another week of welding and we will probably be able to start on the paint prep.

Then the head gasket, etc on the 300D, then maybe the resotration on the 220D, depending upon my finances and level of lunacy!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!