Installing rubber grommets

[hansr433]

What do you all use to lubricate cables, fuel hoses etc which need to fit through a very tight rubber grommet?

[PeterPortugal]

Hans,

When i needed to fit some rubber buffers into my control arms somebody suggested using soap / washing up liquid.

It worked really well and dries off (unlike grease)

Regards

Peter

[doitwright]

If its the firewall grommet you are dealing with check my post. https://www.sl113.org/forums/index.php?topic=29764.msg215661#msg215661

Glycerin is also a good lubricant since it evaporates.

[russelljones48]

here's what my experience has taught me:

in the past: a little soapy water - in a pinch - spit

nowadays: silicone based lubricants.  I keep a spray can of food grade silicone in the garage.  If I want to keep it "lubed" (bushings etc.) I use a very sticky and thick silicone based grease (the almost clear type. 

[hansr433]

Great advice - thanks.  The grommet I am struggling with is 111 997 22 81, which guides 2 gas lines through a hole near the gas filler cap.  The gas lines are very thick, probably non-stock, and go from the filler neck to the gas expansion tank.  I need to lube the gas lines to get them through the tight grommet, or buy the correct gas lines = more trouble and expense.  The attached photo shows the hole which the grommet covers.  I am suspecting the lack of the proper grommet to be the cause for gas smell in the car after a fill-up.

[wwheeler]

I remember that picture and thought those lines seems a little fat. Are yours soft rubber or hard plastic? They should be hard plastic and like vacuum tubing. I doubt you would get the rubber hose through the grommet and into the mounting hole as it is meant for the plastic tubing.

[russelljones48]

here's the CRC 03040 I use...  might take 2 of you (1 to spray and the other to push pull the grommet) but it won't be a greasy mess when you get done you can wipe it off with a little alcohol.  As noted above if it's non-stock and the grommet doesn't match the tubing you may be stuck with replacing the line or devising another solution.

https://www.amazon.com/Grade-Silicone-Aerosol-CRC-03040/dp/B07QN8RY8M/ref=sr_1_2?dchild=1&keywords=crc+03040&qid=1594409899&sr=8-2

[hansr433]

I remember that picture and thought those lines seems a little fat. Are yours soft rubber or hard plastic? They should be hard plastic and like vacuum tubing. I doubt you would get the rubber hose through the grommet and into the mounting hole as it is meant for the plastic tubing.

They are rather fat and relatively easy to bend, but the opening in the grommet is really small in comparison.  I will post a photo of the tubing profile tomorrow and you guys can tell me whether I should be changing them.

[doitwright]

Rubber grommets stretch. The simple method to pass something through a rubber grommet that fits tightly (especially something that has a long way to travel) is to enlarge the hole in the grommet by stretching it just enough. The method I explained in my previous post could be adapted to other grommets also.

[wwheeler]

I think you will see from a photo I attached earlier that these are the incorrect hoses. They should be plastic vacuum tubing and the grommets were designed for that. You might be able to cram these thicker rubber hoses into the grommets, but the grommets are not designed for that and will probably split over time from the stress. Soap is a good lubricant. I would not use grease or a petroleum product because the grommet material is made to resist UV, sunlight and water, not petroleum grease.

Get the correct tubing and everything will go much easier including fitting these into the boots.

[hansr433]

I think you will see from a photo I attached earlier that these are the incorrect hoses. They should be plastic vacuum tubing and the grommets were designed for that. You might be able to cram these thicker rubber hoses into the grommets, but the grommets are not designed for that and will probably split over time from the stress. Soap is a good lubricant. I would not use grease or a petroleum product because the grommet material is made to resist UV, sunlight and water, not petroleum grease.

Get the correct tubing and everything will go much easier including fitting these into the boots.

Wallace, I agree with your assessment, but the original tubing is NLA at places like Niemoeller.  Does someone on the group know of a supplier, preferably in Europe?

[Pawel66]

Check this one: A 000 987 27 27 at Mercedes. EUR 7-8 per meter.
Some of the fittings, pipings, clamps, grommets should also be there.

[hansr433]

Check this one: A 000 987 27 27 at Mercedes. EUR 7-8 per meter.
Some of the fittings, pipings, clamps, grommets should also be there.

Pavel, that's awesome.  I did not find this in my original search, and will add to my list of parts to order.  In the meantime I have acquired 3m of similar tubing from my local hardware store for the princely sum of $.50.

[Pawel66]

Most important you have material to work with.

Certainly these kind of "generic" parts will be much less expensive than MB. But for a user like me (not a mechanic), to look for it, make sure I get the diameters correct, type and quality correct and pay for postage - it is just easier to order from MB that I have 5 minutes drive away...