More 480 Brake Issues!

Brakepads, discs, handbrake. The brakes are crucial for your Volvo 480. Use this category to learn all you need to know!

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eEm
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More 480 Brake Issues!

Post by eEm » Sun Sep 21, 2008 9:08 pm

I've had 198 back on the road for less than a month and BOSH! Noticed what I thought was dew on the tyre from the morning, but then looked at the time! Took a closer look and realised it was brake fluid!

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Leaking from the piston...

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So whipped the caliper apart and got a shock...

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Not as much of a shock as when I got the O-ring out...

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I've done about 1,200miles since I got her back on the road with no problems, I've only just run the discs in. Had the calipers grit blasted and electroplated around xmas time and replaced all the rubber components in all 4 calipers. What I'm concerned about is the electroplate lifting from inside the cylinder and being forced up the sides of the piston causing the above. Obviously I cleaned the calipers with petroleum ether and an airline before reassembly, and used fresh brake fluid etc etc

O-ring appears to be damaged in both directions of movement!

Could have been curtains for me!
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martinholmesuk
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Post by martinholmesuk » Mon Sep 22, 2008 6:54 am

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That's my rear caliper and it's also plated but it was new rebuilt by a company before I got it and I really hope it's not plated inside! TBH your piston looks like it's had a lot of movement to score it like that.

Maybe sand was caught inside? It's a bitch to remove!! Glad you spotted it before you got into problems :D

The piston... is it brand new? it looks healthy. I had to rub mine down on a stone to make it good as it had pitting on the head.


Before and after crap pictures :-(


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How did you insert the piston? I used a g clamp.
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eEm
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Post by eEm » Mon Sep 22, 2008 3:25 pm

Just pushed it in 90% of the way by hand with plenty of fresh brake fluid. Had the calipers grit blasted and electroplated at a classic car restorer's. First thing I said when he handed them back was he should have blanked the cylinders off but he said no. 40 years of experience and he's never had a problem as its the O'ring that seals the piston not the finish on the cylinder.

I must have spent hours just wet&drying the cylinders to get the rough finish of the electroplate off, then blasted with an airline, petroleum ether, then in to an ultrasonic bath, fresh fluid and clean hands then back together. I wouldn't take chances with brakes which is why I'm nearly 100% that they were clean.

Even if they were dirty it doesn't explain the damage to the O'ring. Once the piston is back in it only moves in one direction which is out and I certainly don't have the strength to have damaged it when I was pushing it in.

The crown of the piston was as it should have been although I did give them all a tidy up. I can't explain it. Although you are right, it does look as if the piston has moved the wrong way and yes all pistons were replaced when the calipers were renovated.
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eEm
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Post by eEm » Wed Sep 24, 2008 8:59 pm

Went and saw those lovely people at partsforvolvosonline yesterday to pick up a new set of seals and when they saw the old one they were as shocked as me. They gave me a refund which was nice, although I never even implied the part might be faulty, but never look at a horse's gift in the mouth or whateva.

Got the caliper cleaned up and polished the piston and today I spent about 2hrs with a G-clamp easing the piston back in. It was a much tighter fit than before so I was confident about it all working out. Until I had the whole lot back together and on the car.

I slowly depressed the brake pedal and fluid literally SPRAYED out from behind the pad! :angry: :badmood: :kill:

What am I doing wrong? Why haven't the other calipers gone the same way? I am so angry with this car I could puke blood.
Why won't God heal amputees?

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martinholmesuk
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Post by martinholmesuk » Wed Sep 24, 2008 9:38 pm

how are you fitting the seal? You know it does have a right and wrong way up? It's got a taper fit on the seal.
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martinholmesuk
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Post by martinholmesuk » Wed Sep 24, 2008 9:40 pm

other thing which I don't know but might be true is.... Are the vented and non vented calipers meant to have different seal kits?
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eEm
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Post by eEm » Wed Sep 24, 2008 11:49 pm

54mm piston in both vented and non and one repair kit for both. There is a slightly different kit for pre 89' cars but its quite different so haven't got that.
I put the seal in so that it tapered towards the back of the cylinder ie. thinner end towards the pads, thicker end towards the back, if it went in the other way round the cylinder either wouldn't go in at all or kink the seal.

I'll check the piston for ovality tomorrow and try turning the seal round if its not damaged. I'm going to have one last try and then trade the calipers in for refurbed ones, maybe go for the bigger vented ones and lose the chav discs.
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eEm
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Post by eEm » Thu Sep 25, 2008 9:39 pm

Sorted!

partsforvolvosonline have been sending the wrong size seal. Or my caliper has an odd bore and piston because I found the original seal and its a fair bit smaller than the two new ones that have been mangled.

I had it apart again today and found half the seal in the bottom of the cylinder and the other half where it should have been! And it was still a biatch to remove the piston, but no fresh scoring so I think we're alright.

Put the original seal back in and reassembled the caliper and no leaks so far, although I've only pumped the pedal a few times.
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rgreenhalf
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Post by rgreenhalf » Fri Sep 26, 2008 8:52 am

Well if you need new seals I've rebuilt 480 rear calipers using seal kits from brake parts - http://www.brakeparts.co.uk/

Never leaked so far....
1998 Nissan 200SX - RWD / 260 BHP :)
1990 Volvo 480 Turbo - Sold
1994 Volvo 480 Turbo - Sold
1990 Volvo 480 ES - Broken

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eEm
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Post by eEm » Tue Sep 30, 2008 4:54 pm

Nice one, been drivin this weekend and so far no leaks from the old seal.
Why won't God heal amputees?

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