Volvo 940 with ABS - Spongy break
I wonder if anyone can help me. I renewed the pads in my 940 and as the brakes were slightly spongy {more spongy than in my 740} I bled them.
The result was worse - I could press the pedal to the floor, I went for a test run - clearly not safe.
This morning {Sun 19th may 2002}, I?ve bled the breaks again. Still the same. I am 100% confident that there is no air in the system.
I has a similar prob. a few years ago with a Rover GSI. Even after bleeding the breaks were far too spongy. Upon slackening the retaining bolts on the master cylinder, a quantity of brake fluid ran out - clearly the seals had gone on the master cylinder.
I did the same on the Volvo, no fluid is present at the back of the master cylinder. I?ve checked he whole braking system - no evidence of fluid loss anywhere.
The breaks were q. good before the initial bleeding - no almost useless.
Has anyone one any suggestions. Will it be the master cylinder and if so , then where is the fluid going?
Where is the best place to get a master cylinder {on the Fylde in Lancashire} or should I wait ?till next week.
Could it be anything other than the master cylinder, or could the fluid be passing the sails on the piston of the master cylinder, but not escaping?
How much will a dealer cage, or Volvo / Audi mail order parts supplier for a master Cylinder, or do Halfords stock master cylinders, so should I try a scrap years / Volvo breakers?
Thanks
Paul.
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Not sure about modern cars, but i once found the vacuum unit seals had gone and filled with fluid, replaced it with a unit from the scrap yard, but that was 30 years ago
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What method are you using to bleed the brakes? I have found that the old fashioned pedal-pumping-with-assistant technique doesn't always give good results on modern cars with dual circuit brakes and ABS. I used a Gunsons pressure bleeder (the kind where you attach an air line to the spare tyre) on my Audi with 100% perfect results. I think you can get these kits for about £15 from Halfords.
The other possibility is that you may have fitted the new pads incorrectly. I'm not trying to suggest stupidity on your part - I did the same thing once on a Citroen AX, got the retaining spring in the wrong place so it was pushing the pads away from the discs.
Richard Hall
bangernomics.tripod.com
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Paul,
Richard gives good advice. First you need to think am I sure the bleeding operation was 100%, next have I done something else daft. Only then is it time to consider a master cylinder or further faults.
I would only consider bleeding systems these days with a pressure bleeder as Richard mentions. Also are you sure you have followed any special instructions re bleeding the ABS. Might there be an extra bleed nipple on the ABS unit?
Have you got those odd rear calipers with apparently two bleed screws each? I think only one is for bleeding with that arrangement.
Good luck.
David W
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