Ford Galaxy - Brakes fault finding master cylinder calipers - Sailor

In recent weeks, when braking the brake pedal gave very slightly. I assumed this was the master cylinder, as I had been advised to change it some months back, by an RAC mechanic that checked the fluid and found it in extremely poor condition. Then I bled the fluid right through, but couldn't replace the MC due to difficulties buying one.

I have today replaced the master cylinder, but found when fitting it that the plunger that engages it does so later - about 5mm - as it has slightly differnet dimensions! Which I didn't notice until after fitting it! However now when breaking the pedal "gives" more quickly in sustained braking.. that is: when I press the pedal, once the brakes come on, in order to maintain breaking I have to push the pedal down further and further. It is not driveable.

I expect that one or more of the rubber seals on the calipers are giving up. I've read Heynes on replacing them, but have had difficulty trying to buy replacements. I'm intending to isolate each wheel by clamping the flexible break pipes to see which one is the problem, although really they should all be replaced.

Does anyone have any general advice on all this? Is it worth replacing the seals, or should I replace the whole caliper(s)? Could the master cylinder operate at a different pressure? (It is "supposed" to be the correct one... despite the different dimension mentioned above).

Thanks in advance!!!!

Ford Galaxy - Brakes fault finding master cylinder calipers - Sailor

Since there is no fluid leaking from any caliper, I now think its obvious that they are not part of this problem! A couple of local mechanicis both said it sounded like the Master cylinder, and since I have replaced that it must be AIR. So I've bled it all round, and sure enough got some out! The brake performance is better but still not solved. In the morning more bleeding! Hopefully the bubbles don't get stuck! (Today it seemed that no more were coming out!)

Ford Galaxy - Brakes fault finding master cylinder calipers - Quicksilver

A long time ago I had a 1996 VW Sharan VR6 as a company car. It was the worst lease car I ever had in the UK, (I had one in USA that was even worse).

From new the brakes were very poor with a “soft pedal”. This was the term used by the service garage to try and reassure me it was OK.

After about 6 months so many faults developed that it was returned to the main VW garage for extensive repairs. I had another VR6 as a loan car during this period which had perfect brakes so there was something specifically wrong with my vehicle.

After 4 weeks they told me the car was repaired, (they complained I had put 2000 miles on the loan car!). I went to collect it and the brakes were much better. Apparently they had bled them several times to get them to a more “normal” state.

So if your Galaxy has the same brakes, (very likely) I would say you need to keep bleeding them. Use a pressure bleeder if possible and pay attention to the order of the wheels being bled since on most cars this is important.

Q.

Ford Galaxy - Brakes fault finding master cylinder calipers - jc2

The brakes on your Galaxy are VW parts.

Ford Galaxy - Brakes fault finding master cylinder calipers - Sailor

TY jc2.

Ford Galaxy - Brakes fault finding master cylinder calipers - Sailor

TY Quicksilver. I'll do as you suggest. Your message is the prompt I needed to buy a pressure bleeder.

Ford Galaxy - Brakes fault finding master cylinder calipers - TeeCee

Seconded. I had a company Galaxy for a while, brakes were never great. According to the garage mechanic I spoke to at the time the LHD ones are fine, it's just that the RHD conversion makes a total dog's breakfast of the pipe runs and makes it nigh-on impossible to bleed properly.

I've never managed to get a "hobbyist" pressure bleeding kit to work properly. I am firmly convinced that all the alleged one man bleeding solutions are purest snake oil and that there is no substitue for having someone else shove the pedal firmly.

Ford Galaxy - Brakes fault finding master cylinder calipers - madf

I've never managed to get a "hobbyist" pressure bleeding kit to work properly. I am firmly convinced that all the alleged one man bleeding solutions are purest snake oil and that there is no substitue for having someone else shove the pedal firmly.

Never had any problems at all with pressure bleeding kits. And I am no genius... Easy to use.. Just check tyre pressure is OK, and everything is properly fastened. Of course if you use more than 24psi in the tyre pressure (mine anyway), it leaks fluid and does not work properly.

But then I read - and keep - instructions.

Ford Galaxy - Brakes fault finding master cylinder calipers - Sailor

Just pushed 1 1/2 litres of fluid through using "easybleed" kit with additional pedal here and there. Loads of air on RR. Now when engine run feels much better but not perfect! Heynes says ABS can give probs if air has git into it and its then an expert job.

I'm going to repeat blead all round again and hope I don't have to pay for experts... I'm in East London if anyone has any recommendations here!.

Ford Galaxy - Brakes fault finding master cylinder calipers - bathtub tom

Half a litre's not enough. Try pushing a couple of litres through the system.

Edit . Sorry, mis-read your previous post.

Edited by bathtub tom on 29/07/2011 at 00:53

Ford Galaxy - Brakes fault finding master cylinder calipers - madf

Just pushed 1 1/2 litres of fluid through using "easybleed" kit with additional pedal here and there. Loads of air on RR. Now when engine run feels much better but not perfect! Heynes says ABS can give probs if air has git into it and its then an expert job.

I'm going to repeat blead all round again and hope I don't have to pay for experts... I'm in East London if anyone has any recommendations here!.

Try pushing down on the brake pedal very slowly.. very slowly when bleeding. This may dislodge any small bubbles which are trapped.

Another trick is if on your own is to wedge the brake pedal down to the floor (length of wood between seat and pedal) before tightening up the bleed screw. Stops air re-entering via the bleed screw.

Ford Galaxy - Brakes fault finding master cylinder calipers - Sailor

Hi yes madf, ty.

Well more air came out, and then none as I went four times round the bleed sequence. Now the brakes work and I've driven it. However it feels quite soft, although the brakes respond well.

When stationary with the engine running the original symptom of the pedal giveing after a couple of seconds of pressure is still there, but with firm(er) foot pressure. (than you would need in normal braking)

However there is another problem that I hadn't been certain of before, but has now happened a couple of times as I've test driven it; occasionally the pedal comes up firm without the brakes applying sufficiently. I'm very suspicious of the ABS unit, as I can't thimk what else could interfere! This is quite worrying, and I'm going to have a search for a specialist.... I'll proably try another bleed especially if there's any delay booking it in.

Edited by Sailor on 29/07/2011 at 11:32

Ford Galaxy - Brakes fault finding master cylinder calipers - Sailor

A helpful person from a Clutch Autocentre, suggested I could try bleeding at the ABS unit as the galaxy ABS bleeding is not as specialist as often made out.

If I don't get it sorted I'll probably take it into them tomorrow.

Ford Galaxy - Brakes fault finding master cylinder calipers - Sailor

(After bleeding just the RR which is the one that has yealded air in the past and didn't this time,) I bled each of the 6 connections to the ABS unit one by one, using the easyblead at 20psi (I'd guessed before and it was lower than that), and jamming the brake pedal down whilst retightening each. I think iheard a little air hiss on the two lines from the master cylinder, but it wasn't cleear.

Now braking seems to be reliable on normal driving, coming on consistently at the same pedal depression, and feeling consistent. However three issues remain, The pedal action is quite soft, which I don't thunk is right, the "give" under firm (firmer than needed for normal braking) foot pressure has not gone away completely, but is not apparent when driving (or parking etc), and third and worrying, when heavy breaking, release and immediately reapplying the brakes, full braking isn't available... the pedal feels very firm, as if blocked. This also happens when making two hard dabs at the brakes. (It doesn't seem to happen in more normal braking.) I am suspicious of the ABS, however the ongoing changes after bleeding attempts do suggest that I'm making slow inroads into hidden air pockets!

I'm going to take it to the "Clutch Autocentre" place for some free testing in the morning, and see where we go from there.

Ford Galaxy - Brakes fault finding master cylinder calipers - TeeCee

Define "properly".

If it's supposed to be quicker and easier, yet by the time I've got it all set up, leak free and ready to go I could have had all four wheels off and bled, it ain't right in my book.

Best bits in the kits are the different sized pipes to put on the bleed nipples. Those and an old jam-jar are just so much quicker and simpler.

Last time I tried, I had everything sorted and then the brass nut securing the pipe to the M/C cap thing elected to unscrew itself at an inopportune moment (and yes, I had checked the ruddy thing thoroughly for leaks first!). As I was doing the opposite corner of the vehicle at the time, it put the entire contents of the bottle onto the floor via the engine bay before I noticed something was up!

The one I have now says 20psi. Would it really kill 'em to fit an inline limiter to remove the requirement to deflate and then reinflate the tyre used?

Ford Galaxy - Brakes fault finding master cylinder calipers - Sailor

Driven around today, to garage then back. Mostly fine to drive . Brakes feel comfortable and effective, if soft onder the foot. However the latest problem (see above) of the brakes being very weak and the pedal seeming to resist when re-applying the brakes quickly fter releasing them happens every time.

The garage said there was no air in the system (they bled all wheels and the M/C.). And thought that nothing could account for it except the M/C. They said a Ford dealer/expert was the only chance of a clear diagnosis. (I had thought they initially claimed sufficient expertise!)

However if the vacuum pump is poor, or the vacuum leaking, do you think this could give these symptoms, as after brakeing the vacuum is too slow to be sufficiently re-established?

TY fot your help so far, but if anyone has any further ideas or opinions it would be helpful.

Ford Galaxy - Brakes fault finding master cylinder calipers - Peter D

Is this a diesel engine or petrol. Regards Peter

Ford Galaxy - Brakes fault finding master cylinder calipers - Sailor

Diesel, 1.9TDi. So it has a vacuun pump, not a feed off of the inlet manifold. Not examined pumpat all (yet).

Ford Galaxy - Brakes fault finding master cylinder calipers - Sailor

Well I've just retreived it from the Ford garage, as I was short of time and they didn't have a clear diagnosis. I got a list of other problems, and quotes for dealing with them, but as for the brakes; "we think it best to replace the brake fluid first, then if that doesn't solvie it, we'll need to replace the pump". Unfortunately the customer cannot speak to the mechanic, only the pleasant desk staff, who was not rable to convince me what was really meant by "pump". We agreed it was probably the servo unit, or perhaps the master cylinder, although I also mentioned the vacuum pump.

Next time I take a car inot that kind of garage I will write in advance a detailed description of symptoms, details, and my expectations. eg a list of things to test!

I was told that the ABS unit was fine as there are warning lights on the dash, if it has faults!

I had assumed the specialist tools mentioned in the Heynes manual would be used to check the ABS, etc. But the garage never mentioned any such!!!

Cost £65, plus a cab at£8 and 30 hrs without the car - meaning I had to use the new HS1 train to Faversham!!!

So MY DIAGNOSIS

I think the vacum hose connection to the vacuum pump has been leaking for a while, and perhaps the pump is not working at proper efficiency. This would account for another symptom- the power steering cannot cope with spinning the wheel quickly when parking etc. It certainly explains not restablishing the vacuum quickly after breaking.

The new M/Cyl I fitted, engages with the pedal closer to the floor and therefore more vacuum is used now when breaking than before. This means that a lack of vacuum would now have a greater effect than previously, ie previously it would not have been noticeable.

I still think there was a problem with the old M/Cyl that was solved by changing it, but I let air get into the ABS (with the battary connected etc), and it was only after extensive bleeding and finally bleeding at all the ABS unions that the air was finally cleared (if it IS completely cleared?)

ACTION NEEDED Initially a £1.00 hose clip on the vacuum hose! then strip the vacuum pump and service or replace it.Check all vacuum connections and seals. If it is defective or these actions solve it, then thats all thats essential. If not then investigate the servo unit, howeverthe face the powersteering also seems to lack vacuum indicates a comon fault, ie with the vacuum.

I will probably also source an identical m/Cyl to the original, in order to get the brake to engage at the "proper" depression of the pedal. (there doesn't seem to be an adjustment).

Question Does the power steering use vacuum? I'll look this up. But if not It doesn't invalidate the overall conclusion.

Thankyou all for your help. I hope this story helps others. I will post how I get on.

Sailor.

Ford Galaxy - Brakes fault finding master cylinder calipers - Sailor

P.S. I had pulled the vacuum hose off the V pump, and refitted it, resulting in a reduced problem with loss of vacuum. If it wasn't for the assumption of an expert and definitive solution I would have cancelled the booking at the Ford Garage at that point!

Ford Galaxy - Brakes fault finding master cylinder calipers - bathtub tom

The power steering's only linked to the vacuum pump by (probably) being driven by the same belt, although the vacuum pump may be driven otherwise, camshaft perhaps?

Have you checked your auxiliary belts for tension?

 

Ask Honest John

Value my car