squidgy brakes first pump, then firm. worrying?

[shivars]

Hi,

My brakes recently seem to be quite squidgy iin the first press, with lots of travel in the pedal

But if I then press again within 10-15 seconds its firm, quickly, and with not anywhere near as much travel. (feels much better).

Does this sound like anything to worry about to anyone?

cheers

[Twerlie]

Do you have the Porsche rear hub nuts? if not then they can work loose and cause this! Or your breaks need bleeding!

[V6GTO]

That's classic "Loose hubnut"

Martin.

[shivars]

lol, mine's an older 2.5 so unlikely to have had the nuts changed!

Could I have done anything to cause this or would it likely be natural causes (damn my utter lack of automotive knowledge)? (Went to Goodwood recently, wondering if that could cause it - or if perhaps anything more serious)

[Twerlie]

shivars said:

lol, mine's an older 2.5 so unlikely to have had the nuts changed!

Could I have done anything to cause this or would it likely be natural causes (damn my utter lack of automotive knowledge)? (Went to Goodwood recently, wondering if that could cause it - or if perhaps anything more serious)

If it is the hub nut then it's not your fault. The near side drive shaft should be a left hand thread, but as it is off another car and is a right hand thread, it can sometimes work loose Jack the back up and see if there is any play in the wheel top to bottom, or take the wheel off and tighten the nut until your new Porsche ones come through! Part number: P999.084.641.02 LOCK NUT. About £2.90 each!

Edited by Twerlie on Wednesday 26th September 13:29

[GreenV8S]

Conceivably it's a hydraulic problem but more likely imo you're suffering from pad knock-back. Check the wheel bearings all round and see if you have any flex anywhere.

[shivars]

thanks all for your help!

been avoiding driving, but took it out today and it made some nasty noises from the rear nearside.

So I lightened my pocket by replacing its contents with a socket set and torque wrench and jacked the back up...

Rear nearside was wobbling all over the place; at least 1/4" travel! Ripped it off, gave the hub nut a good seeing to and its all now rigid as it should be!

Next to order those Porsche jobbies...!

Thanks again guys!

[Twerlie]

shivars said:

thanks all for your help!

been avoiding driving, but took it out today and it made some nasty noises from the rear nearside.

So I lightened my pocket by replacing its contents with a socket set and torque wrench and jacked the back up...

Rear nearside was wobbling all over the place; at least 1/4" travel! Ripped it off, gave the hub nut a good seeing to and its all now rigid as it should be!

Next to order those Porsche jobbies...!

Thanks again guys!

Anytime..

[sean_goodman]

is there a visable way to tell the difference between standard and porsche nuts?

[F.C.]

sean_goodman said:

is there a visable way to tell the difference between standard and porsche nuts?

Porsche hub nuts are castellated and cadmium plated (gold colour) they are also very antisocial, straight laced and usually in the throws of a mid-life crisis.
F.C.

[sean_goodman]

is there a hole in the shaft for a spilt pin then? or does one fit them without

[V6GTO]

No split pin.

Martin.

[shivars]

hey if I've now done this and there's no movement in the wheel - but the rear nearside is making shitloads of really loud rubbing/weird noises as the wheel/shaft rotates.

The noise is kinda louder/harder when turning left, and isn't there when turning left.

Its going into the dealer on Friday anyway - but does this sound to peeps like wheel bearing damage from when the nut was loose?

[ThatPhilBrettGuy]

shivars said:

does this sound to peeps like wheel bearing damage from when the nut was loose?

[V6GTO]

New bearing time

Martin.

[shivars]

damnit

safe to drive in the meantime? (incl. 70 mile journey to dealer!?)

[Iaing01]

Probably safe to drive to the dealer to get fixed. Having said that it depends on how long the bearing has been knackered for. The last thing you'd want is for it to seize.

Iain

[shivars]

Ok been to dealer, all exciting.

Out of interest - anyone got (or know where I can get) part numbers for the wheel bearing and the flange? (apparently Ford flange, BMW bearing).

I fancy a bit of DIY...

S