burst sphere ?

BX Tech talk
Post Reply
User avatar
barry badger
BXpert
Posts: 341
Joined: Sun Feb 12, 2012 10:17 am
Location: north west.
x 7

burst sphere ?

Post by barry badger »

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 sorn
Kitch
Over 2k
Posts: 6417
Joined: Sun Jul 03, 2005 9:36 pm
Location: Fareham, Hants
My Cars: Too many to list
x 88
Contact:

Re: burst sphere ?

Post by Kitch »

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.
One third of a three-spoke BX columnist team for the Citroenian magazine.

CCC BX registrar: The national BX register - click to submit a car!

1983(A) 16TRS (Rouge Valleunga)
1990(H) 16Valve (Rouge Furio)
User avatar
Jaba
1K Away
Posts: 1893
Joined: Tue Jul 05, 2005 7:54 am
Location: Usually in the garage
My Cars: BX GTi, C3 Auto
x 80

Re: burst sphere ?

Post by Jaba »

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 BX to my name now. Will I sing Bye Bye to my GTI or will it be Till death us do part.
User avatar
barry badger
BXpert
Posts: 341
Joined: Sun Feb 12, 2012 10:17 am
Location: north west.
x 7

Re: burst sphere ?

Post by barry badger »

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 sorn
rutter123
Over 2k
Posts: 2695
Joined: Sun Sep 02, 2012 9:54 pm
Location: South Lincs
My Cars: 90 Bx Tzd turbo ven red 295k
74 D Super 5 black
05 Volvo V50 2.0d 180k
65 Peugeot Boxer work van 280k
x 136

Re: burst sphere ?

Post by rutter123 »

You fitted the accumulator sphere on the suspension?
90 BX Tzd turbo 294k SORN undergoing major surgery
90 BX Tzd turbo estate 46k awaiting surgery
65 Peugeot Boxer Van the new workhorse
52 Toyota Rav4 180k Bulletproof Jap reliability
User avatar
Jaba
1K Away
Posts: 1893
Joined: Tue Jul 05, 2005 7:54 am
Location: Usually in the garage
My Cars: BX GTi, C3 Auto
x 80

Re: burst sphere ?

Post by Jaba »

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 BX to my name now. Will I sing Bye Bye to my GTI or will it be Till death us do part.
User avatar
barry badger
BXpert
Posts: 341
Joined: Sun Feb 12, 2012 10:17 am
Location: north west.
x 7

Re: burst sphere ?

Post by barry badger »

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 sorn
Post Reply