Brake Basics

[Mr Cerbera]

Hi Y’All

Well, it’s Bank Holiday over here so I am busily trying to bleed the brakes and have discovered an anomaly.
I am using one of those air-pressure-driven, solo, hydraulic, bleeding kits which has worked well on the Clutch previously.
The system pumped in litres of Oil with almost none coming out at the calliper nipple point. I was confused. I checked under the car to make sure that there were no leaks and all was fine.
Luckily I then remembered to check in the driver’s footwell and was astonished to find that it was absolutely pi55ing out at the junction block there.

Is the system not designed to be used with these air pressure systems (currently about about 20psi) or is it a weird leak.

What causes self-doubt is that my brakes have been flawless right up until the moment that I jacked her up

Please point out the essential thing that I’ve forgotten whilst doing this job on a Cerb

Ta !

Mr. Confused

[Tanguero]

Drivers footwell or the drivers wheel arch? The brake junction block is in the wheelarch and definitely shouldn't leak with any amount of pressure. If its leaking visibly form the distribution block could it have been damaged while you were jacking it up?
If the fluid is in the footwell inside the car then the suspect would probably be the master cylinder or assist servo.

[Mr Cerbera]

Tanguero said:

Drivers footwell or the drivers wheel arch? The brake junction block is in the wheelarch and definitely shouldn't leak with any amount of pressure. If its leaking visibly form the distribution block could it have been damaged while you were jacking it up?
If the fluid is in the footwell inside the car then the suspect would probably be the master cylinder or assist servo.

Definitely Footwell here....



I thought that this was a distribution block for the system. Am I wrong in this assumption ?

Oh, Good Grief ! Well, with me it's easily possible to bust summat
BUT
I don't think so this time.

OK, I will try and get a better definition of the leak point.

Ta VM

[Englishman]

Think the brake junction block is in the footwell on early cars and in the wheelarch with a protective panel on later ones.

[Mr Cerbera]

Thanks Englishman. Mine's a Sept 2001 4.5 - which I thought was 'later' but there you go.

Another pic of the current state of affairs...



Looks, at second glance, as if the leak is coming from somewhere North East of the Junction Block - Oh Joy !

(Now where do I go for 'Removal of the Master/Servo')

ETA

Thanks Tanquero - have just found the details on your website - Ta !

Edited by Mr Cerbera on Thursday 5th May 16:12

[billybradshaw]

So, could possibly be that the 20psi has screwed the master cylinder seals.

Here's hoping you can get a quick fix and enjoy the weekend

[gruffalo]

I would take the master cylinder off first and see if that is wet where the actuation rod goes into the servo, if so get a seal set for the master cylinder.

The servo is a pain to get at to say the least and does not have brake fluid in it.

[Mr Cerbera]

billybradshaw said:

So, could possibly be that the 20psi has screwed the master cylinder seals.

Here's hoping you can get a quick fix and enjoy the weekend

Oh that's so sweeeet, Ian.

If I get her back on the road this summer I will be doing well

---

Cheers Gruff, that's brill' advice.
Will concentrate on the Master Cylinder.

Does anyone know if there is any resemblance with the Clutch MS coz I have a spare one of those on my Desk

Edited by Mr Cerbera on Thursday 5th May 16:26

[Englishman]

Mr Cerbera said:

Thanks Englishman. Mine's a Sept 2001 4.5 - which I thought was 'later' but there you go.

Could be the other way around as mine is a July 2001 car, or it could just be the location depended on who was building the car!

This is from the workshop manual, like yours:

Edited by Englishman on Thursday 5th May 16:28

[FarmyardPants]

Is the brake master cylinder reservoir integral with the cylinder itself (like the clutch master), or is it the kind that has a plastic reservoir sitting on top of the aluminium cylinder? If it's the plastic variety you might be pushing fluid out where the plastic joins the main body, since that seal doesn't experience positive pressure under normal use.

Edited by FarmyardPants on Thursday 5th May 16:33

[Mr Cerbera]

Englishman said:

Could be the other way around as mine is a July 2001 car, or it could just be the location depended on who was building the car!

This is from the workshop manual, like yours:

Edited by Englishman on Thursday 5th May 16:28

Ta VM !

[Mr Cerbera]

FarmyardPants said:

Is the brake master cylinder reservoir integral with the cylinder itself, or is the kind that has a plastic reservoir sitting on top of the aluminium cylinder? If it's the plastic variety you might be pushing fluid out where the plastic joins the main body.

Hi Rog,

It's a plastic reservoir that fits flush with the interior bodywork a la ....



Guess I'll have to undo the six screws which locate the bodywork plate surrounding the reservoir first ??

[Tanguero]

Mr Cerbera said:

Tanguero said:

Drivers footwell or the drivers wheel arch? The brake junction block is in the wheelarch and definitely shouldn't leak with any amount of pressure. If its leaking visibly form the distribution block could it have been damaged while you were jacking it up?
If the fluid is in the footwell inside the car then the suspect would probably be the master cylinder or assist servo.

Definitely Footwell here....



I thought that this was a distribution block for the system. Am I wrong in this assumption ?

Oh, Good Grief ! Well, with me it's easily possible to bust summat
BUT
I don't think so this time.

OK, I will try and get a better definition of the leak point.

Ta VM

Definitely the distribution block in the footwell on your car. Good old TVR variability. On my '97 4.2 it is in the wheelarch. Sorry for the confusion.

If its leaking from that, then it definitely shouldn't be, under any amount of pressure! The hydraulic pressure when you are braking is much much more than 20psi

[Mr Cerbera]

Tanguero said:

Definitely the distribution block in the footwell on your car. Good old TVR variability. On my '97 4.2 it is in the wheelarch. Sorry for the confusion.

If its leaking from that, then it definitely shouldn't be, under any amount of pressure! The hydraulic pressure when you are braking is much much more than 20psi

Cheers squire,
thanks for confirming

Now that I've removed the reservoir cover I am convinced that the leak has been coming from the reservoir cap/adapter on the bleeding system.
(Hopefully) will be able to confirm this when I've bribed someone to take part in the tried and tested foot on the brake pedal bleed attempt tomoz.

Thanks all for your speedy suggestions and help

PISTONHEADS ROX !!

[Supateg]

Hello!

Make sure the rubber seal in the bleeding kit cap is present, about 15psi is plenty. Does sound like a poor seal, pressure issue, it's happened to me.

After I consigned the ezi bleed to the bin, I found an easy way....

Put the pipe from bleed nipple submersed in fluid in a jar so air cannot be drawn in and pump away with the break pedal.

Be careful as the reservoir is split in two and the from section you cannot see easy is for the front brake and it is easy to run the system dry even though the reservoir appear to have fluid inside.

Have fun

[Mr Cerbera]

Supateg said:

Hello!

Make sure the rubber seal in the bleeding kit cap is present, about 15psi is plenty. Does sound like a poor seal, pressure issue, it's happened to me.

After I consigned the ezi bleed to the bin, I found an easy way....

Put the pipe from bleed nipple submersed in fluid in a jar so air cannot be drawn in and pump away with the break pedal.

Be careful as the reservoir is split in two and the from section you cannot see easy is for the front brake and it is easy to run the system dry even though the reservoir appear to have fluid inside.

Have fun

Cheers ST

[totalpetrolhead]

Thought this would be the most relevant thread to resurrect rather than starting a new one. Can anybody shed light on what wheelarch side copper line goes into what port of the aluminium brake distribution block? Finally putting the swine back together, and realise I took no reference pictures for what line goes where - I have two front connections and one rear. (New lines follow routing of originals).

[GermanCerb]

From left when you look into the wheelarch:
Clutch - Right Front - Left front - Rear

Good luck
Michael

[totalpetrolhead]

Perfect, thank you very much kind sir!