kboustani

need helo.when i start my 89 c4 in the morning to back up,the explanation,brake,hood lights come on and beeps until i go in first gear,then it stops right away.this only hapens when car is cold.is this normal.

Andy Roe

I used to get this on my C4 sometimes for the first start in the morning. The brake pressure/4WD system needs to get up to pressure within a certain amount of time or else you'll get a warning beep which will stop once it's up to pressure. As the car has been left overnight, then the retained pressure will have dropped lower than what it would have been if you had driven the car 30 minutes earlier etc. I don't think it's something to be too worried about as long as it doesn't beep for long and happen every time you start the car.

I'm sure some C4 owners will chime in, but you should probably check the archives as this will have been covered in more detail before as it's about 8 years since I sold the C4, so I'm certainly not an expert on this!

dfinnegan

How long has it been since the hydraulics have been bled?

- accumulator (bomb)
- valve block
- trans lock
- long lock
- clutch
- brakes (8 nipples)

The accumulator can impact the pressurization time.

Also, check around the pressure switch for any leaks. The switch is a green spark plug-like item that is attached to the pump, which, in turn, is attached to the front of the trunk above the battery. These are known to give up and, if they do, leak hydraulic (brake) fluid into the trunk which eats your paint, and, more importantly, causes near brake failure. The brakes will still work, but require herculean effort to engage; basically, they don't work. Just have a look.

And, bleed the system. All of it.

The pump should run about 40 secs, or less, on start up. If it runs more than a minute you should be looking into things; for sure.

vasculardoc

The other thing is that the brake fluid reservoir level on the C4 seems to be much more sensitive to being under absolutely full - seems that once it is just off being full the alarms go off, and more so on a cold am.

kboustani

how full is absolutley full.i checked it earlier and it looks full but not to the rim.

kboustani

bump

KirkF

Mine does this as well, and has since I bought the car 10 years ago.


Kirk

Laker

Full is up to the full mark on the reservoir, with the car running and the system fully pressurized. The fluid level drops once the system is fired up.

kboustani

ok.thanks to all for the help/

911URGE

+1 on everything dfinnegan wrote. Bleeding the accumulator (bomb) made the biggest impact on reducing pressurization times for me. I went from 30-40 sec to approx 15 sec and over time its slowly getting longer again.

windblown

I love this forum... the search feature is such a great tool when there is so much information to be found here!!!