[s-cars] Changed Pump X-Plug, No Brake Boost - Any Ideas?

[Fred Munro]

Hi Kirby;

There is a spring under the cap which extends when you remove the cap. I
assume the spring loads the piston. I didn't see any orifices. There are no
pumps in the bomb at all, so I assume the pump is not pumping. I'm going to
try re-installing the old o-ring and see if that helps.

Fred

-----Original Message-----
From: Kirby Smith [mailto:kirby.a.smith at verizon.net]
Sent: January 18, 2004 1:36 PM
To: Fred Munro
Cc: s-cars
Subject: Re: [s-cars] Changed Pump X-Plug, No Brake Boost - Any Ideas?


Fred:

I think steering and braking are on separate circuits at opposite ends
of the pump.  Presumably, the high pressure end is the end where the
high pressure hose connects.

O-ring thickness sensitivity is very interesting.  (And raises a
question about design shortcuts, as if we didn't have one given that the
o-rings leak, something that shouldn't happen with a static ring.)  Not
having looked into an x-plug hole, I don't know what is in there besides
a rumored piston.  Are there any orifices near the o-ring?  Did you
change the "compression ratio"?  You get no pumps from the bomb?

kirby



Fred Munro wrote:
>
> Hi Guys;
>
> The hydraulic pump X-plug on my '94 S4 was leaking, so I changed the
o-ring.
> Prior to removing the plug I bled off the pressure from the bomb - it took
> 50 pumps. I pulled the plug and replaced the o-ring with a slightly
thicker
> one I had on hand, so the plug doesn't seat to exactly the same depth. It
> doesn't leak, but the bomb won't pressurize. I ran the car for 5 minutes
or
> so - no brake boost at all. The power steering works fine. Any ideas? What
> circuit is the piston under the plug on - brake or steering?
>
> TIA
>
> Fred Munro
> '94 S4
>
> -----Original Message-----
> From: s-car-list-bounces at audifans.com
> [mailto:s-car-list-bounces at audifans.com]On Behalf Of Dave Forgie
> Sent: January 18, 2004 12:55 PM
> To: s-cars
> Subject: [s-cars] Fumoto Valve and Michelin Man Issues
>
> S-gruppees:  I changed my oil yesterday. While doing so I noticed one
> on-going problem and one "new" one:
>
> 1. There was oil on the intercooler inlet - obviously from a leak around
> the Michelin Man outlet end.  I had this problem before - bad OE gear
> clamp.  I thought that I had cured it with a new gear clamp.  Apparently
> not.  I took the hose off, cleaned out some of the oil puddled in the
> big accordian pleats, cleaned the outlet end of the hose and the inlet
> end of the IC and then put it back together.  Tightened things up real
> good (I think).  Should I be looking at a better clamp, like the ones
> people have used with the SAMCOs?
>
> 2.  I have been running a Fumoto drain valve for years. I thought
> everything was fine but on closer inspection, i.e. during the time I was
> playing with the Michelin Man, I noticed that the Fumoto was weeping out
> the end (not at the ball) where there is a circular plate and an the
> C-clip.  I don't remember this before.  I didn't do anything different
> this time.  Has it always been doing this and I didn't notice before
> because the belly pan got put on too quickly?  (The motor doesn't use
> any oil in 5000 km). The belly pan has oil and dirt on it but I have
> never cleaned it. (Going out right now to the pressure car wash to clean
> it).  Any BTDT's or??
>
> TIA
>
> Dave F.
>
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