Wedge Brake Problem

[Graham]

Ok then one for the tech heads... Last time out in the wedge racer the brakes went from normal to prdal to the floor nothing at all between Lodge and old hall, which at full race speed means you dont need an added fibre diet. After letting everything cool down in the paddock they came back and then would do another 4or 5 laps before the same again.

brake spec is...

All new calipers last season ( front granada rear jag) front pads Ferodo ds3000.
brake fluid brand new castrol SRF ( 40 quid a litre )
brake lines flused with ethanol during off season ( although calipers not pushed right back)
master cylinder replaced over off season.
dual circuit brakes ( front rear)
system checked and re checked for leaks...

Now that symptom suggest boiling fluid, but as i've never boiled the standard dot 4 unlikley to boil SRF. But trapped ethonol in one of the calipers a possibility.

thing is though surley if say the rear caliper had trapped ethonol that boiled when the pressure came off after braking for old hall, wouldnt that mean only the rear circuit would fail and the fronts would still work or am i missing somthing....


any ideas..


G

[wedg1e]

Wild stab in the dark: air got in the system via the master cyl reservoir under hard braking?
I'd agree about one circuit not affecting the other if it failed. Can you blank off the rears and test?
How about the m/cyl seals failing at high temps/ pressure?
Of course if you'd used AUSTIN PRINCESS CALIPERS :cough: it may not have happened...

Ian

[shpub]

Master cylinder seals gone or boiled fluid.
As for Austin Princess callipers... against regs and they are also susceptable to leaks.

[Graham]

But if it was boiling fluid in one caliper wouldnt i get braking in the other circuit ?


Princess calipers, still looking for em mate, when i find them you can have them

G

[wedg1e]

:-D

Not very good at subtle hints I'm afraid!

Just had some arsepiece in a Laguna doing 50+ in a built-up almost take the front end off my car. Looked about 12, the little twat.....

Ian

[350zwelgje]

Graham,

What happend to me on the road seems similar.
Problem: pistons didn't return, and the pads continued to be pushed against the rotor. In the end the result is that your brake fluid is boiling (I use DOT 5.1) with the known result.
I use Green Stuff pads, and they held out! So must be good, and I will stick with them in the future.
Solution: got the callipers revised, with proper tolerance pistons.

All problems now solved, and enjoy proper braking again.

Rob (350i, 300 mm 4 pot callipers)

[Graham]

wedg1e said: :-D

Not very good at subtle hints I'm afraid!

Just had some arsepiece in a Laguna doing 50+ in a built-up almost take the front end off my car. Looked about 12, the little twat.....

Ian

which car not the wedge? how is it you ok

[wedg1e]

Graham said:

wedg1e said: :-D

Not very good at subtle hints I'm afraid!

Just had some arsepiece in a Laguna doing 50+ in a built-up almost take the front end off my car. Looked about 12, the little twat.....

Ian

which car not the wedge? how is it you ok

Yeah, I was coming home in the Wedge. I tend to pootle through the local roads as the pipe is a bit antisocial: don't want to upset the neighbours anymore than the assorted power tools, air compressor and V8s being fired up do already...
Anyway, the main access road runs alongside a council estate, which when I lived there a decasde ago was one of the nicer ones around here. Then the council started moving scruffy bastards from the problem estates in and sure enough they drag things down to their level. Not a day goes by that some 2@ in a Transit dropside full of scrap doesn't cut me up. Of course I have to let it go as my car is a bit high profile around here (and the logo'd company van is too!).
So I was coming into the estate and this little **** in a Laguna exited the road I was about to enter, at the aforementioned high velocity and with, of course, no indicators. Trouble is, he was also on the wrong side of the white line from the side road, and nearly took me out. I stood the car on its nose to avoid him. As I said he looked about 12. Even if he WAS 17 AND had a license, I doubt that he could have afforded the insurance for a Laguna.
There seem to be a lot of cars around here with drivers that look suspiciously too young; considering that my daughter's 19 and was quoted £850 to insure a 20-year-old Fiesta 850 I very much doubt that most of them have any insurance, let alone licenses etc. It looks like the late 80s/ early 90s all over, except that instead of nicking cars they're just buying them and driving them anyway.
Watch out for these tossers, 'cos they aren't watching out for you...

Ian

[DEXY350]

[

wedg1e said: :-

Yeah, I was coming home in the Wedge. I tend to pootle through the local roads as the pipe is a bit antisocial: don't want to upset the neighbours anymore than the assorted power tools, air compressor and V8s being fired up do already...

Even more annoying when theres 2 wedges start up Neil

[DEXY350]

[

wedg1e said: :-

Yeah, I was coming home in the Wedge. I tend to pootle through the local roads as the pipe is a bit antisocial: don't want to upset the neighbours anymore than the assorted power tools, air compressor and V8s being fired up do already...

Even more annoying when theres 2 wedges start up Neil

[wedg1e]

DEXY350 said: [

wedg1e said: :-

Yeah, I was coming home in the Wedge. I tend to pootle through the local roads as the pipe is a bit antisocial: don't want to upset the neighbours anymore than the assorted power tools, air compressor and V8s being fired up do already...

Even more annoying when theres 2 wedges start up
Neil

Would I do that?