i have a 97 840 with a washer bottle in the boot (filled from the bumper with the boot open)and a two in one bottle in the engine bay. the larger part of the two piece one doesn't have a cap? and appears to leak .There are motors on all three vessels and they appear to work but no water to the jets and the jets are clear. Can anyone explain the principal of this weird set up. and possibly a solution. If I knew the set up I will be able sort the problem

Your bottle in your boot is for your headlight wash system, which fills the bottle on the right (the one with no cap)
The bottle on the left is for your windscreen washers.
Do your headlight washers work when you activate your intensive wash?

I'm not sure of a solution if all the motors appear to work. Your best bet for the leak is to replace the bottle, just give a breaker a call they should have them.

Good luck.

Good idea or you may have to go to a main dealer to get the bottle.

The front bottle with no cap is filled by the one in the boot to the level of the float.

The problem is very often the float in the front tank. Orientation of the connector on the float is the first thing to check--the connector should point up.

If the float orientation is correct the rear pump should run if there is fluid in the tank but the float location does not allow the front bottle to ever appear full :(

The float in the front tank is closed when full and the one in the boot tank is closed when empty. Both feed the body electronics module and are not directly connected to the washer system.

I had big problems with the same washer setup and as Terry suggested it turned out to be the float in the washer bottle that was playing up. I cleaned it up and made sure it was pointing in the right direction and everything seems OK.

If i were you I would start by getting some washer fluid into the main bottle under the bonnet. While it doesn't have a cap it does have a breather hole and you can get fluid in there with a bit of patience (funnel or sports drink bottle inverted and squeezed worked for me). With the bottle half full at least does the normal (not intensive) washer work? If not then don't worry about the boot reservoir, you have a more basic problem. If the motor runs but there is no fluid coming out then I would pull the pipes from the jets and see if there is fluid coming out of the pipes. One of my jets looked OK but was in fact blocked.

You say the bottle appears to be leaking, is it visibly leaking? Or is the fluid level making you suspect it's leaking? If it's dripping, you need to take a trip to your champagne BMW dealer as I can't find any UK breakers that have anything for these cars (some claim to have 8s, but they never have the parts I want... :() although ebay.de is worth a look.

Good luck. Nick

The bottle on the right of my car only fills 1/4 from the reserve tank in the boot, does this mean I have a problem with the float?

No, that's what it's supposed to do. The float is positioned at about the 1/4 full position in the bottle, so when the water level gets to that point the float switch tells the pump from the rear reservoir to stop and the water level sits at 1/4. It's like an over-complicated electric toilet cistern! Good news is that with 9L in the boot you virtually never need to refill. My headlight washers don't work so it's not all good....:( I really have better things to worry about though.