Power steering pump/ brake bomb question

[ash2050]

Hi guys,

I took the power steering hose off this morning which attaches to the top of the pump.

The engine was not running but when I started loosening the bolt, the fluid was at such pressure that it spurted out.

Is this normal or is there a problem with my brake bomb?

When I start the car up in the morning I always get the warning light on the dash for around 20 seconds then it goes away.

What do you guys think?

[RichLV]

The pump keeps a 120 bar pressure in those lines, so with a working bomb, which keeps the pressure, I'd say it's normal. Not sure about the light though.

[Error404]

Sounds like the check valve in the bomb is leaking pressure back to the pump. You should discharge the bomb before working on the hydro circuit really.

[Ian Simmonds]

Run the engine, shut down, pump the brake peddle (not agressive as it can shag the master and slave cylinders), until the brake goes properly hard...When you get to 50/60 pumps, it's a healthy bomb, check the fluid levels, adjust and repeat...

Purging the system of air means getting the front steering wheels off the ground and getting 'lock to lock' as air in the system tends to rock up in the rack...

Having just mastered the issue with our Ur, its imperative the air is 100% purged, and the system is 100% charged... It does take some proper time.

[UrS4boy]

How our UrS Power Brake System Works

When I start the car up in the morning I always get the warning light on the dash for around 20 seconds then it goes away. What do you guys think?

I've had that light for more than 18 years. Brakes still work. (It's just the PB pump getting the system up to pressure after sitting overnight - might be a slight leak in the pressure accumulator check valve but nothing to get real excited about (in my opinion). As long as its only 15 to 20 seconds, not minutes that is.

How our UrS Power Brake System Works:

http://forums.quattroworld.com/s4s6/msgs/25095.phtml

[Error404]

You can "fix" that annoying light by unplugging the pressure sensor on the servo

[ash2050]

Thanks for the replies.

My light does go off after a few seconds.

I've noticed that my brake pedal is a little spongy when driving and the brakes don't feel as responsive as they used to.

At a traffic light, if I pump the brake pedal continuously, the brake pedal is a lot stiffer when I drive off and the brakes are a lot more responsive.

After braking a few times when driving, my pedal is a little spongy again and there is more travel on the pedal and the brakes don't feel as responsive.

Could this be something to do with the brake bomb or a bit of air in the brake fluid?

[ash2050]

Thanks for the replies.

My light does go off after a few seconds.

I've noticed that my brake pedal is a little spongy when driving and the brakes don't feel as responsive as they used to.

At a traffic light, if I pump the brake pedal continuously, the brake pedal is a lot stiffer when I drive off and the brakes are a lot more responsive.

After braking a few times when driving, my pedal is a little spongy again and there is more travel on the pedal and the brakes don't feel as responsive.

Could this be something to do with the brake bomb or a bit of air in the brake fluid?

Anyone got any insight on this??