Brake Fluid Container Empty But No Obvious Leaks

[feb 47]

So today was the first time I started up the car after 6 weeks, I thought of taking it home to charge the battery since it has been sitting since after the new year.

 

The first thing I noticed when I pushed the brake pedal was that it went almost to the floor while hearing a whistling sound (as if you are trying to inflate a tyre/matress with a foot pump).

 

I thought the master cylinder had gone.

I continued my journey to charge up the battery keeping long distances and taking it easy.

It gradually got worse and I had to stop at a petrol station to have a look.

To my surprise the brake fluid reservoir was empty.

It took about 200-250ml to fill up, I had to push the pedal a few timesand refill to bring it up to level.

 

I can brake now although the pedal still goes almost to the floor (I guess air has gone into the system so the brakes need bleeding now) but I wouldn't want to drive the car like this as for anything more than a gentle stop it is just not efficient.

 

I parked home and checked the level again after a few hours and it hasn't gone down, I took a look in the engine bay, around the rear hoses and under the front and couldn't find any obvious leaks.

 

So the question is where has the fluid gone?

 

I'll take a better look tomorrow, jack up the car and remove the wheels.

 

Would it be possible that the master cylinder has gone and would that have the symptoms I see?

 

If so what is the part number/brand of the master cylinder I need?

 

Thanks.

Edited February 17, 2012 by feb

[Toddy 7]

Obviously you have a leak somewhere, I would wedge the pedal firmly down with a metal bar/jack handle during daylight and check for leaks underneath the car periodically, you may need to bleed the brakes to get a firm enough pedal to carry this out. Then resolve issue and bleed the brakes.

 

You only need to do the above if the leak isn't obvious.

 

The whistling noise will be when you pressed the brake pedal without the engine running and this released the vacuum in the servo.

Edited February 17, 2012 by Toddy

[feb 47]

The whistling noise will be when you pressed the brake pedal without the engine running and this released the vacuum in the servo.

 

OK, I'll ask my wife to push the pedal down while I look around for leaks.

 

Regarding the whistling noise, I hear it everytime I break suddenly/push the pedal to the floor (which is really easy to do now).

 

Btw, we had down to -17C a few weeks ago, could that have caused the brake fluid to freeze hence bursting a union or something or is my imagination too wild?

Edited February 17, 2012 by feb

[Daviewonder 533 3 Cars]

Master cylinder seal has probably gone and all your brake fluid is sitting in the servo.

[feb 47]

Master cylinder seal has probably gone and all your brake fluid is sitting in the servo.

 

Thanks Dave, how do I go about resolving this, just replacing the O ring or new master cylinder altogether? (obviously I'll take it to a garage but it helps to know what the problem is and have the parts I need at hand otherwise it will be a head scratching moment and I might be skinned off)

Edited February 17, 2012 by feb

[Paul_13 212 1 Cars]

I'd have a good check of all the rubber flexi hoses, I had a flexi split and there was no obvious sign of a leak.

[feb 47]

I'd have a good check of all the rubber flexi hoses, I had a flexi split and there was no obvious sign of a leak.

 

No rubber hoses AFAIK, the car has almost new copper brake pipes and SS hoses.

[Daviewonder 533 3 Cars]

Best to buy a complete new master cylinder if that is the problem as they're not expensive. Should take about half an hour to fit if all the pipes come undone ok.

[Paul_13 212 1 Cars]

No rubber hoses AFAIK, the car has almost new copper brake pipes and SS hoses.

 

Ok sounds like master cylinder then

[welshpug 1,657]

20.6mm Bendix item is what you need same as a mk2 golf amongst a few other vehicles.

[feb 47]

Now that you say I realised it is in the list of parts Anthony gave me when I bought the car

 

Question, how do I blank off one port of the new master cylinder? Weld or screw?

[Paul_13 212 1 Cars]

Is there a blanking plug already in place on the existing MC?

[feb 47]

I have to check, no idea

[Anthony 1,003]

Yes there is - it's a 4 port MC that's has a blank fitted to make it a 3 port.

 

Are you sure that there's no leaks, as that MC wasn't very old and was a decent item so surprising if it's died already? Indeed, the whole braking system isn't that old and was completely replaced 3-4 years back.

 

MC failures don't typically lose fluid unless it is leaking into the servo.

 

Double check that it hasn't spat a rear brake pad.

[jason7579 5]

If it is master cylinder it's a very easy job And the new Bendix one I got the other day from gsf came with 2 blanking screws in the box.

[feb 47]

Thanks guys.

 

I had another look today and there are no leaks so I am going to bite thet bullet and want to replace the master cylinder and the cylindrical thing (what's it called? - brake booster/servo unit?) that I assume the liquid has leaked into?

 

I guess the arctic circle temperatures we had killed it.

 

Can someone confirm what parts I need from

 

http://public.servic...A&idFct=FCT0039 : just 4601 A9 (diam 20.6 Bendix) will do, or should I order 4633 96 (master-cyl kit) ?

 

and http://public.servic...A&idFct=FCT0039 - 4535 F0 (diam 200 Bendix) ?

 

Do I need any other parts (I assume O-rings etc.) and are the above part numbers correct? I'd rather replace more than necessary for peace of mind since brakes are important!

 

I appreciate if someone with a 1.9 could PM me their VIN as if I order wihtout part numbers, Peugeot parts are a pain in the ass (my car was initially a 1.6 that uses the 1.9 setup)

 

Jason, out of interest how much did the Bendix master cylinder set you back?

 

Thanks for letting me know what to get!

Edited February 18, 2012 by feb

[jason7579 5]

Gsf no. 652vg0200 part no. 65268 desc. Brake mas cyl -20mm total including vat £40.14. Also got 1l of dot 4 brake fluid £5.40 Inc.

[feb 47]

Gsf no. 652vg0200 part no. 65268 desc. Brake mas cyl -20mm total including vat £40.14. Also got 1l of dot 4 brake fluid £5.40 Inc.

 

Thanks! Good I didn't buy one from the local motor factors they wanted 95 f€cking euros!

[sensualt101 31 1 Cars]

clearly you have a leak somewhere feb and i hope you find and solve it soon.

 

the only time my brake pedal dropped to near the floor on a 205 gti was my old phase 1 graphite 1.9.

 

in extremely hot weather on long journeys involving summer traffic jams driving quickly then stopping and starting a lot.

 

strangely i never found any fluid loss and the pedal feel always returned when cool so it put it down to the fluid boiling but never rally got to the bottom of it?

[jason7579 5]

If it helps I found fluid in my drivers footwell, not sure were exactly it came from so maybe it could get soaked up in the underlay?

[feb 47]

Anyone?

 

Assuming I have no leaks (I can't see any) I will start by replacing the master cylinder and brake servo, I appreciate if you could confirm me the part numbers mentioned 5 posts above

Edited February 19, 2012 by feb

[omega 82]

if its still a 1.6 set up on the back have you checked if the wheel cylinders are leaking?

[feb 47]

Omega, the car has discs on the back.

 

I did a search in the forum but couldn't find an answer to this: if the MC was leaking into the servo unit, wouldn't the servo leak through the pedal box and into the cabin? I don't see any fluid in the cabin.

 

We had a look under the car on a ramp (calipers, brake lines, hoses) and there are no obvious leaks, I have no leaks in the cabin and after refilling the brake fluid container as mentioned earlier (took about 250ml) the level hasn't dropped at all since (did about 500km+ on a private test track afterwards).

 

Rear pads are in place.

 

I am really puzzled and don't have much confidence in the car.

 

Where the car was parked for 6 weeks there are no traces of fluid on the floor either.

 

Is there a way to check if the fluid has leaked into the servo without making a mess?

 

Once the servo arrives, my plan is to get someone to replace it together with a new MC.

 

Do you guys have any better ideas?

 

My lack of ability/confidence working on a car (apart from basic things) together with the lack of 205 specialists around here might make 205 ownership difficult in the long run.

We'll see.

It's always difficult until you find a local garage that knows what they are doing and which you can trust. This is the main problem anywhere. Until then ...

 

Btw, do you want to hear how much Peugeot wanted to charge for replacing the MC and servo?

 

I only asked out of curiosity (since I was there to enquire about parts prices) as I have no intention of being skinned off alive.

 

20.6mm MC: 111 euros

servo: 200 odd euros

labour 2h (at 100 euros/h)

Total: 500 euros

Ha!

 

The culture here is replace the car with a new one and not fix. A friend of mine was telling me the other day about his collegue who was quoted 5k euros to have the clutch changed in his BMW. In the end he sold the car!

Edited February 25, 2012 by feb

[jason7579 5]

If you can get the old master cylinder off without snapping anything it really isn't hard to replace. I am not a mechanic by any stretch of the imagination but I don't mind getting diry and it took me about an hour. Just soak the bolts that you will be undoing in some kind of penetrating fluid if possible ( although I just used wd40 and grease).

 

As said before I had oil in the footwell but not sure if it may leak elsewhere, I'm sure I have seen it mentioned that it could leak into the servo and remain in there but I'm not 100%

 

I havent changed a servo so can't help with that.

[feb 47]

A "strange" thing that has happened is that the brake pedal has gained much better feel over the last few days and doesn't need to be pressed to the floor as previously (in the past it would almost sink to the floor - would that indicate there was air in the system that has been purged now over a period of time or does it still indicate a misbehaving MC/servo?)

 

Also the brake performance has increased now.