Hi all, car is a 1994 UK coupe 2.6 auto, 115k miles.
A year ago, I made the mistake of putting brake fluid in the power
steering fluid reservoir, I realised the next day and drained the
fluid, replacing it with regular red steering fluid - another big
mistake. 2 weeks later the car dumped all of it's fluid, and my garage
diagnosed failure of the power steering pump. They replaced it, and
since then the car's been fine, but the brake light flashes for up to
a minute on a cold start. On a warm start it doesn't flash. Also the
steering occasionally creaks. A couple of months ago the car was
MOT'd, and the rear brake pads changed, no other problems reported,
and this is a reputable garage, I trust them.
Another point is that I've researched this, & tried the brake 'bomb'
test - switching the engine off, and pumping the brake pedal - it
takes over 40 pumps to go hard.
Any ideas what's causing the flashing light?
On Sun, 04 Nov 2007 19:01:11 -0000, email@example.com wrote:
I am not sure about your model, but on the earlier models, the warning
light can have three possible causes:
1: Low brake fluid level.
2: Low hydraulic oil level.
3: Low hydraulic pressure.
I'd say your bomb is slowly leaking. Try the bomb test before you
start the engine after a night's rest.
I tried the test this morning, after leaving the car over night, and
the brakes were hard straight away (before starting the engine) - does
this indicate the bomb is leaking? There's no loss of fluid, the level
has been fine for ages.
On Tue, 06 Nov 2007 14:51:11 -0000, firstname.lastname@example.org wrote:
Leaking may not be the correct word, but yes, it confirms my
suspicion: Fluid is slowly seeping back into the reservoir. Notice how
the fluid level is a little higher after the pressure has had time to
Note that the car I used to have is not the same as yours, so what I
say might be completely irrelevant:
I can think of two possible causes. One is the pump. I that case,
however, you'd have to have two check valves fail in a similar manner,
i.e. both having a slow leak. I don't think that is likely.
The other possible problem is that the brake booster (the one that the
brake pedal activates) has a slow leak so that the pressure from the
bomb slowly seeps through the valve and into the return line to the
To test: Disconnect the brake booster return line from the reservoir
and place a jug under the open end, so that you catch any fluid that
comes out. Start the engine and let the bomb charge. Don't touch the
brake pedal while the return line is disconnected, or you'll make a
mess. Stop the engine, note the reservoir fluid level, and leave
In the morning, if there is fluid in the jug and the reservoir level
is unchanged, the booster is bad. If the jug is empty and the
reservoir level has increased, the pump is bad.
If you have other hydraulic components, such as suspension, they can
also be the cause of the problem.
On Thu, 08 Nov 2007 00:49:52 -0000, email@example.com wrote:
No. The booster is the hydraulic actuator that sits between the brake
pedal and the master cylinder. It looks a lot like the master
cylinder, and is bolted directly to it.
The booster has two hydraulic lines connected to it: One is the high
pressure from the bomb, and the other is the return to the reservoir.
Do NOT disconnect the high pressure line unless you are absolutely
sure the bomb is discharged, because the pressure in that line is very
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