burst sphere ?

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barry badger
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burst sphere ?

Post by barry badger » Wed Mar 28, 2018 11:19 pm

I had a really bizarre problem with my 4x4 today.
1 week ago I fitted 5 exchange spheres which totally transformed the ride, however whilst driving today i felt a sensation through the brake pedal, like when abs is triggered, only my car hasn't got abs, when i was stationary i pressed the brake pedal really hard, which caused the rear brakes to stick on so that the back end was dragging. They slowly released whilst i was driving but still didnt feel right, I got the car back to my workshop and took the pads out of the rear to check them, they were ok and weren't sticking, I then bled them in case the sensation through the pedal was caused by air, i had the suspension in the high position and when i lowered it there was a lot of burbling and hissing from the reservoir. I didn't think too much of it at the time other than it was strange, but when i road tested the car the back right suspension was rock hard. The brakes now feel fine.
I'm convinced the diaphragm has ruptured on the sphere, but could it have released pressure into the rear brake circuit causing the brakes to lock on, i've done 4,000 miles in this car since july and had it for seven years, it seems odd this brake problem has happened since fitting the spheres and now seems to have rectified itself now that ( i think ) the sphere is empty.
If the sphere really has burst i've not really got faith in all of the others.
1993 tzd estate, on sorn
1992 tzd estate, slowly being raided for parts
1992 txd estate, "doom blue" on the road
1991 4x4 estate, on the road

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Kitch
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Re: burst sphere ?

Post by Kitch » Thu Mar 29, 2018 10:00 am

Certainly sounds like possibility, though I can't see how a sudden shot of Nitrogen into the system would make the brakes jam on. If anything, they'd lose effectness, as all brakes do when they've got air in. Plus, the rear brake circuit isn't linked to the suspension after the DV, so I don't know how it could get on there. The brake circuit is a dead-end too.

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Jaba
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Re: burst sphere ?

Post by Jaba » Thu Mar 29, 2018 10:21 am

I think your diagnosis is spot on Barry. It is certainly possible for a diaphragm to rupture and for the N to find its way into the brake lines and I suppose into the doseur but how it then holds the brakes on with gas pressure is difficult to imagine.
I have had a rear sphere which leaked its N into the brake lines, but very slowly over a period of many months. The rear suspension would rise, or was it drop, when reversing and applying the brakes. Bleeding the brakes effected only a temporary fix. Eventually when I changed the spheres one of them was very full of LHM.

I need to buy some new spheres soon for my GTi. What make were yours as they are probably best avoided even though this would probably be just a one off manufacturing failure.
The Joy of BX with just one Citroën to my name now. Will I sing Bye Bye to my GTI or will it be Till death us do part.

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barry badger
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Re: burst sphere ?

Post by barry badger » Fri Mar 30, 2018 11:24 pm

Update on this, the right rear sphere had ruptured, it was still bubbling when i took it off. I've put the old accumulator sphere in place of it for now and the suspension and brakes feel fine . I'll have to see how the brakes go, hopefully it was to do with the sphere and not something else developing.
The sphere suppliers were very helpful and are sending me another one to replace it, don't really want to name them as they have been very good and hopefully this is a rare event.
1993 tzd estate, on sorn
1992 tzd estate, slowly being raided for parts
1992 txd estate, "doom blue" on the road
1991 4x4 estate, on the road

rutter123
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Re: burst sphere ?

Post by rutter123 » Sun Apr 01, 2018 8:36 pm

You fitted the accumulator sphere on the suspension?
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Jaba
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Re: burst sphere ?

Post by Jaba » Sun Apr 01, 2018 9:48 pm

Yep, it could be called the (temporary) 2CV comfort conversion if it rides as we would expect.
The Joy of BX with just one Citroën to my name now. Will I sing Bye Bye to my GTI or will it be Till death us do part.

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barry badger
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Re: burst sphere ?

Post by barry badger » Thu Apr 05, 2018 10:52 pm

The rear spheres don't have valves on the 4x4, i've had accumulator spheres on this for the last 5 years, but it feels better now with the proper 500s. My replacement sphere arrived yesterday, so car is back as it should be.
It's got me wondering though what a non 4x4 would feel like with accumulator spheres on the back!
1993 tzd estate, on sorn
1992 tzd estate, slowly being raided for parts
1992 txd estate, "doom blue" on the road
1991 4x4 estate, on the road