Brake Master Cylinder

[andyjstone 6]

I have read some stuff on this, but can't find a definitive answer and specific reasons!

 

Car still has a 1.6 master cylinder, which was replaced earlier this year along with all the brake lines.

 

Have recently changed the front calipers to GTI6 units and about to change the rear drums to calipers.

 

With the GTI6 calipers everything seems to work great, I have no issues, but I see some posts on here that say you should change the master cylinder to a 405 unit.

 

Three questions:

 

1. Is this really necessary and why?

2. Would the 405 master cylinder fit on the 205 servo or do I need to change this as well

3. Are the above much bigger than the 205 units as there ain't much space between the '6' lump and the head for anything bigger

[swordfish210 20]

You can use the 23.8mm master cylinder from a 406 without any problems. You may want to tilt the servo up a bit to gain some extra clearance between the master cylinder and the rocker cover.

[andyjstone 6]

You can use the 23.8mm master cylinder from a 406 without any problems. You may want to tilt the servo up a bit to gain some extra clearance between the master cylinder and the rocker cover.

 

But is this necessary?

 

I read some other post that said that this really doesn't make much difference to the braking force, but does it give a different front/back split or something?

[swordfish210 20]

Depends whether you're happy with the amount of pedal travel you have with your current master cylinder or not. If you fancy a bit less travel then change the master cylinder.

[Anthony 1,002]

As said, it's pedal travel that the size of the MC effects - 23mm 406 MC noticeably reduces the pedal travel over a standard 20.6mm GTi MC, but if you're happy with the travel as it is, why change?

[andyjstone 6]

As said, it's pedal travel that the size of the MC effects - 23mm 406 MC noticeably reduces the pedal travel over a standard 20.6mm GTi MC, but if you're happy with the travel as it is, why change?

 

OK, pedal travel seems a bit long at the moment, but I'll check it again after we've changed the rear brakes and then decide - just wanted to make sure there wasn't any safety issue, just an operational one

[andyjstone 6]

As said, it's pedal travel that the size of the MC effects - 23mm 406 MC noticeably reduces the pedal travel over a standard 20.6mm GTi MC, but if you're happy with the travel as it is, why change?

 

So where do I get a new one of these from, is there a part number or a specific model/year it comes from??

Edited September 24, 2009 by andyjstone

[EdCherry 34 1 Cars]

GSF or Peugeot, be prepared to remortgage your house for it though.

[Anthony 1,002]

So where do I get a new one of these from??

New? Most places should do them - it's an early 406 non-ABS master cylinder that you're after. Be warned though that they're quite expensive - something like £80-90 from memory

 

You'll also need a blanking plug to turn it into a 3 outlet MC seeing as yours originally started life out as a 1.6 GTi

[andyjstone 6]

GSF or Peugeot, be prepared to remortgage your house for it though.

 

Yes, I found a new on the net that looked a bit steep, but there seem to be a few different types

[andyjstone 6]

You'll also need a blanking plug to turn it into a 3 outlet MC seeing as yours originally started life out as a 1.6 GTi

 

Does it matter which of the outlets gets plugged up?

[swordfish210 20]

You'll also need a blanking plug to turn it into a 3 outlet MC seeing as yours originally started life out as a 1.6 GTi

 

The last M/C i bought came with 2 spare blanking plugs. Ideal

[Anthony 1,002]

Does it matter which of the outlets gets plugged up?

The MC is split circuit (like 205 ones), so put the two front calipers on one circuit, and the rear line on the other (with the spare blocked).

 

Basically, copy how it's done on the current MC(rear and blank nearest the servo, two front brake lines furthest from the servo) and it'll be fine

[andyjstone 6]

The MC is split circuit (like 205 ones), so put the two front calipers on one circuit, and the rear line on the other (with the spare blocked).

 

Basically, copy how it's done on the current MC(rear and blank nearest the servo, two front brake lines furthest from the servo) and it'll be fine

 

Thanks for clearing that up - not sure I'm going to do it yet, but I've banked the info in case!

[andyjstone 6]

OK, been looking into this a bit more. The MC was changed earlier this year when the brake lines where replaced and looking at it maybe it has already been upgraded. These are some pics:

 

 

 

I'm assuming this isn't the standard 1.6 unit which would have had 3 pipes I assume and this has four with one blanked off, so is this a 1.9 unit or one from a 406 or something else??

[EdCherry 34 1 Cars]

That could just be the 20.6mm Bendix unit that GSF etc supply now, I have exactly the same for my track car, and when they get it right one for my road car as well!

Edited September 26, 2009 by EdCherry

[Redtop 14 2 Cars]

You can't get the 3 outlet master cylinder for the 1.6 gti anymore from pug as I tried to get one last week. They don't do a seal kit for them either. The link below is the standard 1.6 mc that should be on your car but that bedix one you have is a 4 outlet with 1 blocked off. I'd say thats why it was put on it.

 

http://forum.205gtidrivers.com/index.php?showtopic=109676

[tony perks 1]

On my car I have the 406 turbo diesel M/C this one had ABS and is 23 mm and only 2 out lets which is great for a rally car, the pedal travel has been much reduced and much firmer too.

[mr_exe 1]

Going slightly o/t here but in there any merit in using an uprated master cylinder (say a 406 non abs) with the 1.6 brakes with a view to reducing the pedal travel?