My master cylinder appears to be leaking at the grommit that attaches the tank to the cylinder. I got 2 new grommits at the dealer. Is there anything I need to know to replace these?

My plan is to mity-vac the fluid out of the tank
lift the tank out
pull out the old grommits
lube the new ones w/brake fluid
put them on the tank
push tank into position
refill

Can I just bleed out the tank or do I have to bleed the whole system?

I am hoping it is just the grommits before I change out the whole cylinder.

__________________

Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT

As long as you don't touch the brake pedal while the tank is off, you shouldn't have to bleed anything. Once you get it back together and refilled, pump the brake pedal a few times, and make sure you have a decent pedal before you go anywhere.

+1 to a thorough verification, but it IS a good time to bleed all around...

__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)

#1. Use the mity-vac to extract the brake fluid from the reservoir.
#2. Remove the brake fluid level connector from the reservoir.
#3. Pry the the brake reservoir off with a large screw driver.
#4. Remove the old grommets from the master cylinder.
#5. Lubricate the new grommets with fresh brake fluid.
#6. Install the new grommets to the master cylinder.
#7. Lubricate the reservoir nipples.
#8. Put the reservoir nipples against the new grommets at a slight angle, and give it a good solid whack with your hand or rubber mallet to seat it.
#9. Refill the brake reservoir.

I LOVE this forum.
Roy --- you give such great shade tree directions, even I with very little experience knew exactly what you meant.

__________________
daw_two
Germantown, TN

Links:
Sold last car --- 05/2012 1984 300D Light Ivory, Red interior
Cluster Needles Paint
New Old Stock (NOS) parts

Past:
3/2008 1986 300SDL "Coda"
04/2010 1965 190D(c) "Ben"
& many more

Thanks every, esp whunter.

How do I drain the front resevoir? Got the rear empty, but can't figure out how to access the front?

__________________

Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT

Not possible, because of the internal reservoir design.

* Use a layer of towels under the master cylinder to catch it.
* Allow it to spill, washing (dish soap) the body metal as soon as possible.

If you prepare/plan correctly:
Changing the grommets takes roughly two minutes, then you can clean up the mess.

No brake bleeding needed for this DIY.

Exactly as described- about 2 minutes and now I can lock my wheels up with the brakes!!


I was able to get a yogurt tub under the cylinder and catch pretty much everything from the front by lifting it up just enough to drain out.

Thanks again! Heck of a lot better than replacing the whole cylinder!

__________________

Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT