Rear Discs and Wheel Bearings

[kerrinmay 0]

I had new brake discs fitted to the rear of my C yesterday and was told that the wheel bearings also had to be done as they were sort of integral with the disc and if they tried to remove and reuse them they probably wouldn't be any good. Does this sound correct?

[gibber 0]

Its not far from the truth!

And would be wise to do them both at the same time.

[Andy T 0]

Yeah the outer race of the bearing is pressed into the brake disc, well worth changing at the same time because you don't want to have to strip it all down again six months later when the bearings get noisy

[kerrinmay 0]

OK, thanks for the advice. I was just wondering how much to trust the garage that I took my C to yesterday as when they replaced the brake discs and pads they didn't bother to bleed the system properly or top up the brake fluid, resulting in a problem with lack of pressure in my clutch and them telling me to take the car back to the main dealer because they had fitted a new clutch slave cylinder in November and it looked like there was a problem with that!

 

Subsequently took the car back to main dealer last night, made a big fuss/scene about the problem and them not having a courtesy car for me and not wanting to pay for a hire car, and now VW have rang and said it's all related to the brakes being replaced yesterday! So wasn't anything to do with work they had done! All a bit embarrassing really :oops:

[kerrinmay 0]

The problem with the clutch started on Saturday when I was sat in stop-start traffic for 1 1/2 hours. Is it possible that constant up-down of the clutch pedal could bring any air in the system to the surface and result in a drop in pressure on the pedal?

 

The pedal had got to the point where it wouldn't return completely to the top using hydraulic pressure, the last bit of return was just on the spring. Then when the garage changed the brake discs and pads this just got a lot worse, I guess as a result of them loosing some fluid in the process and then not topping it back up.

 

Does the first bit about constant up down of the pedal sound feasible?

[Roger Blassberg 0]

Mmmm. A bit surprised that changing the brakes caused the fluid level to drop. Normally it would rise as the pistons were wound back into the caliper to accommodate the new pads. Maybe they opened the bleed nipples on the calipers in a vain attempt to just push them in, and then the light dawned and they wound them back in the correct way.

 

Best wishes

 

RB

[kerrinmay 0]

Not sure who to believe now. The main dealer or the VW (so called) specialist. I shall have to quiz the dealer a bit more when I go and collect the C to find out why they believe it was low due to the brake change yesterday. Was there something that pointed them to that conclusion?

[Supercharged 2]

Hmmm, strange one, as RB says the fluid will rise as they wind the rear calipers back altho they may have bled the rears and not topped up the fluid?

 

Depends if the slave is leaking or not really but this is hard to tell at first as they start to leak internally...

 

kerrinmay, suprised the local garage refered you back to the main dealer unless they were sure the slave was faulty, it does make sense what you said about the pedal btw...

 

Jeezz - can we trust any garages any more, my mates at work think i'm mad when i take a day off work and do a 300mile round trip to stealth just because I don't trust anyone round here to work on my car...

[kerrinmay 0]

Can't even get hold of the local garage now, phone has been engaged all day! It must be off the hook or something. I'd like to find out if they did bleed the brakes etc (if they remember). The slave cylinder was new back in November so I'd like to think there isn't a problem with that.

[kerrinmay 0]

Just spoken to the local garage and they say that they didn't bleed the brakes at all. However I then spoke to main dealer and they say they found spilt brake fluid on the gearbox that isn't near anything that could have leaked and points to the fact that someone looked to top up the reservoir. The main dealer also say they fully tested everything and found no leaks or fault components in the system!

 

Who do I believe???!!

[Roger Blassberg 0]

Curiouser and curiouser!!

 

Unless you have a LHD car, the reservoir is on the offside and the gearbox is on the nearside, so I don't understand this line of thought.

 

Best wishes

 

RB

[kerrinmay 0]

Great, just when I was beginning to believe the dealer I'm now unsure again! Will just have to chat to the Technician at the dealer when I pick up the C to try and find out exactly what they've looked at and what they found. I've been speaking with an After Sales Advisor so it might be that they didn't understand everything the technician told them or it's a bit of chinese whispers!

 

All I want to be sure of is that there is nothing wrong with the clutch hydraulics and that everything is ok. Although I would like to understand how it got so bad. I can sort of believe that my constant gear changing of 1 1/2 hours sat in slow moving traffic (pumping the clutch up and down) contributed to the slight problem I had with the clutch before the brakes were done yesterday, but it's more why they had got increasingly worse with the pedal almost all the way to the floor when I collected it from local garage after the brakes were done yesterday.

[Andy T 0]

To me it sounds like your clutch problem is pure coincidence.

 

I had exactly the same problem with my clutch last year, even with a new slave cylinder I would loose the clutch pedal after a longish drive, but it never occured after 20-30 minute drives.

 

Your problem is the Clutch Master Cylinder (on the bulkhead, connects to the clutch pedal). The seals will be on their last legs, and the heat build up from a long drive causes air to get past the seals into the master cylinder.

The problem will get worse and worse until the clutch will not disengage at all!

 

I did find that if I Bled the clutch system afterwards, it would work again for ages (at least until I next went on a long drive!)

 

So you need a new Master cylinder, GSF & ECP don't sell them any more for Corrado or Passat, (unless things have changed) It was about £90 from VAG but at least cured my clutch completely.

 

I think even if the garage did disturb the brake hydraulics, its unlikely to affect the clutch as the systems are seperate apart from sharing the fluid resevoir. You would of had no brakes though!

[Supercharged 2]

Leak ontop of gear box = Leaking Slave cyl.

 

kerrinmay, clean a fluid off the top of the gearbox and keep an eye on it, I reckon the new slave may be leaking (this could happen if they didn't bleed new fluid into it when it was changed and water in the fluid has just knackered it)

[Henny 0]

could also be that the pipe TO the slave cylinder has become porus... I've seen a few of these do this recently... :|

 

It's the flexible pipe with the coiled metal bit which attaches to the slave cylinder... if the outside of the rubber bit feels oily and damp then it's time to replace it... ;)

[geordiedubber 0]

I have the same problem with my clutch at the moment, After a longish drive the pedal goes to the floor, Iam hoping its the slave cylinder as the master seems to have been replaced at some time. Got a price for the slave: stealers £80.06 ,Ecp £35.00 :shock:

 

I bled the slave and it lasted a day...

How do I bleed the master cylinder ??

[Andy T 0]

The fluid on top of the gearbox could just be from the old slave cylinder or when they bled the new one - worth a closer look.

 

I'd of thought that if a VAG garage fitted the slave cylinder the system would of been bled throught with new fluid..??

[kerrinmay 0]

Thanks for all the advice.

 

Got C back from dealer last night and everything seems fine. They had their 'Master' Technician work on it and they bled the system through, topped up the fluid and say they found not faulty components or signs of leaks.

 

So fingers crossed for now, however if it happens again then I'll take a look myself, bearing in mind the potential problems that you've all suggested!

[kerrinmay 0]

Clutch pedal started going a bit again yesterday (i.e. stopped returning properly). I'm thinking 'Andy T' that it might well be the same as your problem. Is there any easy way to tell if the Master Cylinder is on it's last legs? Perhaps I should just get a new one and change it. Is this a difficult and time consuming job to replace? Any ideas on how long it should take and will I have enough access to it if I put the front of the car up on axle stands?

[Supercharged 2]

It may have gone when the slave was playing up - A faulty slave will put more stress on the master...

 

The master cyl is the bit that the pedal connects to, right next to the brake servo/and brake master - have a look at it and check that for fluid leaks...

 

Should take a garage 1 hour to swap and bleed fluid.

[kerrinmay 0]

Was considering buying the part and replacing it myself, should this be easy to do?

[Andy T 0]

Replacing master cylinder is fairly easy...

 

Working inside car at clutch pedal, prise off clip that connects master cylinder to clutch pedal, and undo the two bolts that hold the unit to the bulkhead.

 

Remove some fluid from the brake reservoir until it is just below the braided pipe that goes to the clutch master cylinder cyl(but not low enough to get air into the brake pipes!)

 

Pull of braided pipe that connects master cylinder to the brake fluid reservoir, at the reservoir end. you'll need a bowl & rags to catch any fluid that may come out. Undo pipe union on the cylinder (possibly 11mm spanner) to remove pipe that runs to the slave

 

Remove master cylinder from engine compartment (bit of a squeeze past the brake servo!)

 

Fit new cylinder, connect pipes & pedal and secure bolts. Top up brake fluid reservoir and bleed the clutch system with new dot 4 fluid in order of Master first then slave cyl.

 

Easiest way is to use a tyre pressure bleeding kit (works fine for me), or the two man bleeding method which will be explained on here somewhere.

 

I reckon its an hour / hour & half job. Warning the clutch will feel bizarre for first few hours of driving... will feel stiff then sometimes soft but it will settled down eventually!