All,

Now that I have a job where I can afford the Later SD brake swap to the front of my TD, I'd like to replace the master cylinder first... I replaced it a year ago, but the seal on the tail of it is leaking into the booster, sooooo...

I see the later SDs have a cylinder machined out of aluminium, instead of being cast steel, didn't know if they would mount and work for what I have in mind...?


TIA

__________________
---------------------------------------------------------------

1998 VW Cabrio
2001 Audi SomeRoad A/T (no air suspension)
2003 Audi DeadRoad M/T (no vroom, for later)
2002 Audi NoRoad A/T (nothing under the hood, being rebuilt)

The MC bolts to the booster, so if the booster is very similar, the MC should fit. Insure the later MC has the 3 ports you need, and in the correct positions for your tubes. I recall there is an adjustable tip coming out of the booster that might need tweaking so you neither have excessive "lost motion" in the pedal nor compress the piston initially so it is past the fill port. You should get the brake fluid out of your booster first. I had that on both my W123's. I removed the boosters and let them drain for months, w/ rags to pull the fluid out by capillary action. I also repainted the boosters since glycol fluid is a great paint remover (now have silicone fluid in both cars).

__________________
1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

Bill,

Did you do a write up on changing over to Silicone fluid? What is the procedure and approx cost?

__________________
85 300D turbo pristine w 157k when purchased 161K now
83 300 D turbo 297K runs great. SOLD!
83 240D 4 spd manual- parted out then junked

The boosters are indeed different, so that makes me think the throw of the rod in the booster will likely be different too, negating the idea of a later master cylinder being a bolt-on improvement...

__________________
---------------------------------------------------------------

1998 VW Cabrio
2001 Audi SomeRoad A/T (no air suspension)
2003 Audi DeadRoad M/T (no vroom, for later)
2002 Audi NoRoad A/T (nothing under the hood, being rebuilt)

Here is a good read.

Can an SD brake booster be wedged into a W123?


Charlie

__________________
there were three HP ratings on the OM616...

1) Not much power
2) Even less power
3) Not nearly enough power!! 240D w/auto

Anyone that thinks a 240D is slow drives too fast.

80 240D Naturally Exasperated, 4-Spd 388k DD 150mph spedo 3:58 Diff

We are advised to NOT judge ALL Muslims by the actions of a few lunatics, but we are encouraged to judge ALL gun owners by the actions of a few lunatics. Funny how that works

First read the imagined horrors from people who never used DOT 5. Some even claim it causes more rust by not absorbing water that drips/condenses into your reservoir. I haven't seen that in 15 yrs using silicone (my 1965), and seems such mythical water would also be a problem in power steering reservoirs. Some claim "spongier", but my pedals are hard. But, be careful not to entrain bubbles (pour slowly down side of funnel) and let it sit for days if you drop the jug since it takes much longer for air bubbles to settle out. BTW, the blue dye will fade so it looks light amber but that is not degradation or rust. Also bogus rumors that it eats seals, indeed some 1950's British cars required silicone brake fluid since glycol ate their seals.

Best to swap when changing major components like MC, hoses, and calipers. I recall doing my W123's w/ MC and hoses, but not calipers. Blow all tubes and calipers clear w/ air. I then put a little ethanol in tubes and blow that thru, then wait days to dry (have extra cars). Don't believe myths that silicone reacts w/ any leftover glycol. Hobbyist engineers have tested that (search) and marked "bogus, counterman-spread rumors". Also don't believe the legal disclaimer mumbo on the bottles. Worst issue is any leftover glycol bubbles may contain moisture, so might be smart to sweep thru a little clean glycol first. I haven't put silicone in my two ABS cars, but like most engineers I suspect it would work fine and that is more input from corporate lawyers (no qual tests run).

Hardest part is buying it cheap. I bought 1 gal military surplus twice for ~$70 (it is/was standard for military vehicles). Many production motorcycles use it, but in tiny 1 pt bottles. Auto parts stores carry it, but pricey in the qt bottles. Don't over-bleed, and once you sweep the junk out you can filter & re-use what you bleed. Hopefully, you will never need to break into the hydraulics again.

__________________
1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

If you make yourself cunifer metal brake lines, they will not rust from inside or outside.

Fedhill brake line - Where to buy brake line, fuel line, brake line flaring tools, brake line nuts and brake line fittings

I haven't done it but if I keep the 190D for a while, I might.

__________________
CC: NSA

All things are burning, know this and be released.

82 Benz 240 D, Kuan Yin
12 Ford Escape 4wd

You're four times

It's hard to

more likely to

concentrate on

have an accident

two things

when you're on

at the same time.

a cell phone.

www.kiva.org It's not like there's anything wrong with feeling good, is there?

Thanks for the link, Charmalu, looks like the key is the booster... Therefore, it Appears that I can retrofit that instead and get the benefit I'm wanting... Only thing is, I still don't know if the booster movements are equivalent or not.

__________________
---------------------------------------------------------------

1998 VW Cabrio
2001 Audi SomeRoad A/T (no air suspension)
2003 Audi DeadRoad M/T (no vroom, for later)
2002 Audi NoRoad A/T (nothing under the hood, being rebuilt)