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Fitting Brake Master cylinder
Posted: 12 Dec 2017, 19:19
by itchyfeet
Never fitted one before.
Any pointers so I don't make school boy errors gratefully received
P1080926 by
Paul_Barr, on Flickr
Re: Any tips on fitting this?
Posted: 12 Dec 2017, 21:37
by captain Byrne
Yes.. make sure you fill it with brake fluid first so it's well primed. The rest is pretty straightforward, have plenty of rags knocking around to wipe up inevitable spillages. Other than that it's just a straight swap.
Obviously bleed the system as you'll no doubt know.
Re: Any tips on fitting this?
Posted: 12 Dec 2017, 21:46
by bigbadbob76
Never done one on a T25 but done a couple on cars and it's pretty straightforward.
(except on the wife's old renault, i had to do it through the pedal plate cos it was hidden behind the engine.
)
obviously you want to drain the level down a bit first so you don't get fluid everywhere, the fluid attacks paint something hellish.
Don't drain down any more than you have to or it makes bleding the system more difficult. just down to below the outlets is good.
You'll get some drips anyway so covering things up in that area is worthwhile.
Re: Any tips on fitting this?
Posted: 12 Dec 2017, 22:34
by nevill3
I remember doing mine on an early (1983) 1.6D and found that there was an extra hole in the new one compared to the one that was on. ( It is for an extra "brake failure sensor??) I couldn't get a blank for it so I just inserted another brake switch sensor as a bodge!
Re: Any tips on fitting this?
Posted: 12 Dec 2017, 23:16
by volks_womble
It's not a bodge... the US models have 2 brake light switches in case of failure. There is an additional socket on the loom for a second bake light switch...
What I would say is - do not over tighten the brake light switch, as it splits the boss (and is why I now know how to change the master cylinder...)
Re: Any tips on fitting this?
Posted: 13 Dec 2017, 07:44
by itchyfeet
Thanks for the tips
Re: Any tips on fitting this?
Posted: 13 Dec 2017, 07:59
by slowcoach
volks_womble wrote:It's not a bodge... the US models have 2 brake light switches in case of failure. There is an additional socket on the loom for a second bake light switch...
What I would say is - do not over tighten the brake light switch, as it splits the boss (and is why I now know how to change the master cylinder...)
Oh! Makes sense now. Mine has two sensors connected and is an oz model. Three pin switches too, which confused brickwerks at the time
Re: Any tips on fitting this?
Posted: 13 Dec 2017, 08:56
by itchyfeet
volks_womble wrote:It's not a bodge... the US models have 2 brake light switches in case of failure. There is an additional socket on the loom for a second bake light switch...
What I would say is - do not over tighten the brake light switch, as it splits the boss (and is why I now know how to change the master cylinder...)
not just us models, my late vans both have two switches
P1060232 by
Paul_Barr, on Flickr
Re: Fitting Brake Master cylinder
Posted: 26 Dec 2017, 16:48
by itchyfeet
Fitted this today, pics as usual
clocks off and check the old one looks like the new one before removing it, had wrong parts before
P1090096 by
Paul_Barr, on Flickr
top off and filter out
P1090102 by
Paul_Barr, on Flickr
syphon off the fluid
P1090101 by
Paul_Barr, on Flickr
I could not believe the black dirt at the bottom
P1090104 by
Paul_Barr, on Flickr
clutch master cylinder feed off
P1090105 by
Paul_Barr, on Flickr
goes to clutch master here, that will need bleeding later too.
P1090099 by
Paul_Barr, on Flickr
brake switch connections off and then 11mm spanner removed1st brake pipe, bit of tube on so nothing gets in
P1090107 by
Paul_Barr, on Flickr
then the other brake pipe off
P1090108 by
Paul_Barr, on Flickr
then you can release 2x m8 nuts
P1090109 by
Paul_Barr, on Flickr
and it comes off
P1090110 by
Paul_Barr, on Flickr
Re: Fitting Brake Master cylinder
Posted: 26 Dec 2017, 16:55
by itchyfeet
Pulled the reservoir off, best wear goggles it went suddenly and sprayed me with brake fluid
plugged holes, added some fluid and shook it to release the dirt
P1090112 by
Paul_Barr, on Flickr
refitted clean tank to new cylinder, swapped switches over, these are tapered thread so don't want to be silly tight.
P1090114 by
Paul_Barr, on Flickr
refitted it and filled reservoir
I didn't fill the cylinder I wasn't sure how to without it pouring out all over the dash
P1090116 by
Paul_Barr, on Flickr
pressure bled kit on, tyre down t 15psi
P1090117 by
Paul_Barr, on Flickr
went round once but air was still inside, so I went around again but this time I pressed the pedal while it was bleeding, then bled the clutch and finally went around one last time.
each fill of the pressure bleed bottle is 0.5 litres, best not to let it run out or you get lots of air bubbles, stop just before release tyre pressure and refill.
I put 1.5 litres through.
P1090118 by
Paul_Barr, on Flickr
refitted clock and test drove it, seems fine now
Re: Fitting Brake Master cylinder
Posted: 26 Dec 2017, 17:15
by colinthefox
Itchy
Thanks for that, a really good clear explanation.
Re: Fitting Brake Master cylinder
Posted: 26 Dec 2017, 17:55
by Oldiebut goodie
While you were there, did you happen to notice where the fluid level connector drops down to when it falls down? Can't find mine for love nor money after last fluid change!
Re: Fitting Brake Master cylinder
Posted: 26 Dec 2017, 18:26
by itchyfeet
Oldiebut goodie wrote:While you were there, did you happen to notice where the fluid level connector drops down to when it falls down? Can't find mine for love nor money after last fluid change!
where it ends up is any bodies guess but this is the cable, may help to find it?
level sensor cable by
Paul_Barr, on Flickr
Re: Fitting Brake Master cylinder
Posted: 26 Dec 2017, 18:26
by itchyfeet
colinthefox wrote:Itchy
Thanks for that, a really good clear explanation.
Thanks for he encouragement
Re: Fitting Brake Master cylinder
Posted: 26 Dec 2017, 18:37
by Oldiebut goodie
Thanks -I am very wary of pulling on just any cable in there given how delicate the wiring is. Knowing my luck something else will get disturbed.