delay in braking / harsh ride?

deian · Unread post by **deian** » 21 Apr 2006, 11:56

Ever since i changed my accumulator sphere, my brakes have been a slow to react.

Story goes like this, i changed the acc.sphere and of course made a bit of a mess due to a badly designed seal, all is ok now, but i lost some fluid, but i put a 1 litre bottle into the LHM tank to top it up. Which I believe was enough to recuperate the loss. I also do citroebiotics all the time. It's quite cool to do, so I do it! Especailly after the sphere change.

But lately the brakes have been slow to react and fierce upon gripping. So much so that the ABS kicks in often. Along side this I've noticed the suspension has been a little harsher than usual.

Another clue I have is when i do citroebiotics when fully down and going to the top the ((!)) and STOP lights comes, then goes off after a few seconds. There are no external leaks to my knowledge.

So have you guys got any ideas at all? I can't really check my LHM level as the float is stuck (at the top, always, even when lowered)

. I guess some Hydraflush will be needed. But is there any other obvious ideas that could be shared.

Thanks

Unread post by **RichardW** » 21 Apr 2006, 12:04

The braking delay is usually caused by gas in the brake lines. Most likely the rear lines, and the most likely cause is the anti sink sphere rupturing. So...bleed the brakes first off and see what comes out.

It's OK for the light to come on when selecting high from low - you open the height correctors and they suck all the pressure out of the system so the light comes on for a couple of seconds whislt it repressures. Nothing to worry about as long as it goes out and she comes up again

The level should be checked on high with the engine running. Unlikley the float is stuck, more likely the tank is overfull.

If the LHM in the tank is yellowy green, then it could do with a change. If it's v dirty then yes hydraflush it.

PS: It says in your title 'harsh ride' - has it gone hard at the back? That may indicate a failed rear wheel sphere rather than the AS one.

deian · Unread post by **deian** » 21 Apr 2006, 12:20

Ok thanks, I have plans to hydraflush her, it will do a lot of good to her I think. And I also plan to change all the sphere over the next few months. First one i did was the accumulator sphere which was easy.

So if I change the rear anti-sink next? i understand this acts as the centre sphere too right? hence the harsh ride? or is it the rear accumulator that acts as the centre sphere? (it's hydractive 2, so i have 8 spheres)

Also I will bleed the brakes, can't think how air got into the brakes though. So how do I do this... just open the bleed nipple, put a pipe over it and feed the other side of the pipe into the LHM tank?

As for the sticky float, it's on high when the car is low too, and i look in to the LHM top up hole when it's high and it still seems half way, where should the fluid be by looking into the hole?

Also, the rear doesn't sink to the bottom when sitting in the boot as it should (which is why i changed the front accumulator sphere), still the same, so I guess the rear spheres need changing, all of them!

Honestly now, I've never seen the STOP light come on before when doing citrobeotics until i change the accumulator sphere. Funny.

I'm very fussy and a perfectionist here so I will get to the root of the problem. With your help.

Thanks

Mandrake · Unread post by **Mandrake** » 21 Apr 2006, 12:36

When you changed the accumulator sphere, its possible to get a bit of air into the system if you don't follow the right procedure...

The best approach is to have the suspension right down, open regulator bleed screw, do the sphere change, then start the engine with the regulator bleed screw still open and watch through the top of the tank - you'll probably see a bit of frothing as the air pocket that was sitting at the end of the sphere is expelled.

You can also close the bleed screw for 30 seconds to let pressure build up then open it again to eject any remaining gas. Finally with the bleed screw closed if the surface of the oil in the tank is calm you can raise the car to normal height.

Keeping the suspension right down while bleeding the regulator prevents any air finding its way into the suspension or rear brakes. Provided you don't press the brake pedal during this none should go into the front brakes either.

If you started the engine up with the bleed screw closed immediately after changing the sphere some air may have got into the system, doing Citrerobics should expell it from the suspension but the brakes may need bleeding.

As for the anti-sink sphere, as mentioned by RichardW it won't affect the ride but the rear "centre" hydractive sphere certainly will. (Which is actually mounted off to the right a bit, facing downwards)

For bleeding the brakes (assuming you're doing it by yourself without a helper to press the pedal) the way I find works well is:

Lift the suspension right up, jack up one corner at a time with a trolley jack under the corner of the suspension chassis (near the bolts that bolt the chassis to the body) and remove that wheel, then wedge the brake pedal down with a piece of 4x2.

Now you can either attach a pipe from the bleed nipple back to the tank or to a small jar. I just use a small plastic peanut butter jar with a hole in the lid for the pipe. Closing the bleed nipple before releasing the brake pedal gives a better result, so having the pedal held down with a piece of wood works well.

If you use a container be sure not to take too much oil at once - no more than about 1/4 of a litre, then stop and tip it back in the tank, otherwise you run the risk of running the resouviour low in level and pumping MORE air into the system than what you're removing

You can't really judge the level of the oil by looking into the hole due to the wideness of the tank, suffice to say at maximum car height the oil in the tank is at minimum level and vica versa, and the gauge is calibrated to read the minimum level that occurs at maximum height.

At normal height or if its overfull the gauge will be pinned to the top. (It's just a plastic ballcock float) The full range of the gauge is equal to less than half a litre of oil.

Regards,
Simon

fastandfurryous · Unread post by **fastandfurryous** » 21 Apr 2006, 12:56

Mandrake wrote:If you use a container be sure not to take too much oil at once - no more than about 1/4 of a litre, then stop and tip it back in the tank, otherwise you run the risk of running the resouviour low in level and pumping MORE air into the system than what you're removing

Just to add to that, if you use a super-long length of clear hose (washer hose from the front of a car to the back window is ideal) and poke the other end back into the tank, then you can bleed litres and litres from the brakes with no fear of drawing air back in. Works particularly well on the rear brakes, as you may have to bleed nearly 2 litres of fluid before some trapped air comes out.

Unread post by **Peter.N.** » 21 Apr 2006, 13:20

If the ride at the back has gone hard, I would try the centre sphere first. The most difficult to remove but most rewarding when replaced

deian · Unread post by **deian** » 21 Apr 2006, 14:16

i was thinking the same thing fastandfurryous, pipe back into the lhm tank,

what i will do is bleed the brakes, change the accumulator and centre sphere in the back, and hydraflush her

as for changing the sphere technique mandrake, it's all done now, but i will bare it in mind next time, i did do citrobeotics after the change,

thanks guys

Homer · Unread post by **Homer** » 21 Apr 2006, 20:15

deian wrote: As for the sticky float, it's on high when the car is low too,

With the suspension on normal or low the float should be stuck against the top.

When you have the suspension on high and the four suspension cylinders full of LHM the level should drop enough for the float to come down so the marker is between the lines.

As has been said, it is very unlikely the float has stuck since there is very little to "stick" it. It works pretty much like a fishing float, siting on top of the LHM.

deian · Unread post by **deian** » 21 Apr 2006, 21:43

I guess i'm ok there then, the LHM looks green enough, a little cloudy maybe but i'm sure it could be a LOT worse.

AndersDK · Unread post by **AndersDK** » 21 Apr 2006, 22:33

Delay in braking is caused by air/gas in the FRONT brakes system. Not the rear brakes.
Front and rear brakes circuits are completely isolated to each other - even the pressure source to the brake valve is isolated. The delay is caused by the time it takes for the system pressure to compress the gas. When you release the brake pedal the pressure releases and the gas expands again - ready for next delay cycle ...

Any gas in the rear brakes circuit will cause the rear end of car to shoot up on braking as there is no braking force on rear wheels to pull down the rear end.

deian · Unread post by **deian** » 21 Apr 2006, 22:49

Mandrake about bleeding during acc.sphere change said above:

Provided you don't press the brake pedal during this none should go into the front brakes either.

So there I was, the new boy opening the bleed valve when the suspension was on high, and pressing the brakes, etc, THAT explains it all, definately a bleed job soon.

Lesson learnt!

Thanks guys.