brakes loosing pressure.

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gsa60
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brakes loosing pressure.

Post by gsa60 » Sat Dec 28, 2013 7:12 pm

Hi;
My turbo is fitted with an abs brake system that is causing some issues. the system is an ATE.
when I press the brake, the low pressure light lits up for about half a second. I can hear the relay of the pump switching on and then off this half second. If i push the pedal further, the relay turns on and off again.
Also, with the car standing still, after some time the pump turns on for a while which makes me believe that the accumulator is leaking.
The question is: is this part serviceable. If not how hard is it to replace the hole abs unit (accumulator; pump and master cylinder)
Thanks and happy new year

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glasgowjim
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Re: brakes loosing pressure.

Post by glasgowjim » Sun Dec 29, 2013 12:47 am

Ate means nothing to me , a photo would help as I have spare abs unit(might even have 2 or 3) also brake master cylinders 2 types so a picture or description would help . does it have a controller unit in the rear ?

what year is your car?

am working with very limited internet access just now.

gsa60
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Re: brakes loosing pressure.

Post by gsa60 » Mon Dec 30, 2013 8:39 pm

Hi Jim;
I think ATE is the brand.
I have no pic of the pump here but mine is equal to the car in the "car of the month" of the site. Namely the car from March 2004. Here is the link http://www.volvo-480-europe.org/clubdat ... h/0403.php.
Cheers

gsa60
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Joined: Tue May 21, 2013 10:18 pm

Re: brakes loosing pressure.

Post by gsa60 » Tue Apr 01, 2014 8:30 pm

Finally got a replacement pump from a scrapyard. Looks good.
So.... risking looking like a fool: has anywone replaced an ABS pump in these cars? can anyone give me any general steps and tell how hard it is.
I have a bit of mechanic diy experience (replaced head gasket and similar dificulty jobs) but I've never replaced an ABS pump.
cheers

Alan 480
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Re: brakes loosing pressure.

Post by Alan 480 » Wed Apr 02, 2014 8:52 pm

depending on the type of ABS you 'might' be lucky and only need to change the controller unit.

this means that you do NOT have to touch the hydraulics in any way!!

what year is it (a turbo I guess) but cant see the ABS unit in photo :-(
Alan

480 ES 2litre x 2, C30 1.8ES, SS1

gsa60
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Joined: Tue May 21, 2013 10:18 pm

Re: brakes loosing pressure.

Post by gsa60 » Wed Apr 30, 2014 12:28 pm

Hi Alan.
The issue was a leak in the master cylinder and also on the accumulator.
Anyway it's replaced. Had a little trouble bleeding the rear brakes though.
This one works .
Only doubt that I have is that after some brake pedal applications the relay clicks. But I'm 90% sure that's supposed to be that way so pressure is kept.

Flying Dutchman
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Re: brakes loosing pressure.

Post by Flying Dutchman » Thu Jan 08, 2015 6:54 pm

This worked for you in long term? Got similar problems with mine. Exact same unit..

Mine does the fanatic "clicketyclick" when braking to often, and then the ABS lights up. Think the mian problem is leaky accumulator or main cylinder? Or both?

Brakes very good, but pedal feels spongy in the upper part.

Any suggestions would be much appreciated. :)

gsa60
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Re: brakes loosing pressure.

Post by gsa60 » Thu Jan 08, 2015 11:21 pm

HI,
Yep! It's still working.

I'm in no way an expert on that breaking system. But I believe that the symptom of a leak in the accumulator is: When you have ignition key in pos. II (engine does not need to be running) after the braking system is pressurized, wait some minutes. If the pump kicks in I believe its a leaky in the accumulator.

Note that on my faulty unit, every time I pressed the break pedal, even lightly, break pressure light would turn on. I'm not sure what does it mean when only the abs light turns on.

In the "new" unit the pump turns on after I press the pedal a few times, but no light turns on. I believe this is normal behaviour.
There was, in fact, one time the pressure light turned on. This was after the installation of the new unit. In order to test it pressed the break pedal many times as fast and hard as I could :bla: the light turned on briefly.

NOTE: I might be wrong.

Sorry I can't be of any more help.
BR

Flying Dutchman
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Re: brakes loosing pressure.

Post by Flying Dutchman » Fri Jan 09, 2015 2:58 pm

Thanks!

Did, or do you experience any sponginess in the pedal? Mine is quite soft in the upper half.

:)

gsa60
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Re: brakes loosing pressure.

Post by gsa60 » Thu Jan 15, 2015 10:36 pm

Hi,
I can't fell any sponginess. There's however, a little slack on the pedal. I mean there is a (very) little distance that the pedal descends without engaging the brakes.
Hope it helps

Flying Dutchman
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Re: brakes loosing pressure.

Post by Flying Dutchman » Fri Jan 16, 2015 9:18 pm

Helps alot! Tells me theres something wrong with mine.. Bet there is some air left even though Ive bled them twice. ;)
Thanks! :rofl: :rofl:

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