RE: bomb rebuild - the thread that wouldn't die

[Aleksander Mierzwa <alex@matrix.com.pl>]

Mike wrote:

	>Found some gen-you-wine Audi sales info from 1986 vintage, and
there was a
	>cutaway and operation description of the famous Lemforder bomb.
	>
	>1. Drawing clearly shows a threaded plug at the mounting end of
the bomb.
	>On the 89 100 bomb I have on my bench, this plug (if present)
is under the
	>mounting stud which is spot-welded to the dome, and thus
probably
	>inaccessable (chisel?). Earlier model bombs (1988 and down) may
not mount
	>this way, so the plug may be accessable - fairly easy recharge
here, if
	>this is the case! Anyone got an older bomb to look at the plug?
Suggestions
	>on remove and replace the mounting stud to access the plug?

The bomb form my 87 5K also has the mounting stud. I inspected the
inside of the stud with a flashlight and couldn't see a plug.

	>When the brakes are not applied, accumulator filled with
pentosin to 150
	>bar, whereupon the 150 bar valve opens and vents excess
pentosin to the
	>reservoir. (Accumulator never exceeds 150 bar.) System is
stable.

I already asked this question, but got no responses: how much fluid
remains in the bomb after the pressure has been released? I bought a
used bomb (and will _never_ do this again) that had been used with ATF
in the past. I wonder if the amount of ATF left in the bomb can do any
harm to the hydrulic system in my car.

	>3. Checked in Burden's Surplus Hydraulics catalog
(1-800-488-3407), found
	>the following:
	>	pressure accumulators, 10 cu in (11" long) and 29 cu in
(16" long), 3000
	>psi max, fill with schrader valves (!), $79.95 each, new.

I've got a better alternative: Citroen suspension spheres (similar
construction, shape and size as Audi bomb, although probably without the
valves): $20 (!!!) from the local parts store.
A buddy mechanic of mine has given me the address of a place that can
order a new bomb from Germany for about $260. A h*ll lot of money, but I
will probably go this way. This means I will have two old bombs to
experiment with. The first one is probably the original 10 years old
bomb from my car (the p/n begins with "443"). Because it still gives
some signs of life, I suspect that while it losed the pressure, the
valves may still be OK. This could be recharged. My second bomb is a
newer one (p/n begins with "857"), but apparently has been run on ATF. I
believe it still may have lots of nitrogen pressure, but the valves are
stuck because of the ATF. This might be cured by cleaning the valves.
Both bombs look like they can't be dissasembled except for one bolt
located in the valve area. What will happen if I remove this bolt?

	>>P.P.S.   Saw a 164 <Alfa, not Volvo> with a rusted-out right
rear quarter
	>panel >Saturday.  Very disappointing for a car with a
galvanized body.  You
	>never see any rust >on galvanized-body Audis, even in
Minnesota, home of
	>road salt <snip>

I've heard that 164s were not galvanized until 1992. Even after then it
wasn't full double sided galvanization like on our Audis. 

Aleksander Mierzwa
Warsaw, Poland
mailto:alex@matrix.com.pl
87 Audi 5000CS turbo (mine)
88 Renault Medallion wagon (mom's)
91 mountain bike (just in case both cars broke at the same time :-)