Iron/steel master cylinder change

[Arthur 20]

Hi all.

 

Sorry if i open the gazillianth topic about master cylinders. I have a 1985 lacoste. I have upgraded to 9 inch booster vessel years ago and I run 266 fronts discs, gti drums at the rear. ( about 200 bhp EC8 engine now)

 

I assume the cylinder is still from 1985 and 19mm since it's cast iron/steel and has 4 brake lines. The mounting holes to the booster is 180 deg. (horizontal)  The only reason I want to change is the rust on the cylinder outside. It's fine but it just looks scrappy. I'm fine with pedal travel but would not mind a bit firmer feel at the expense of having to put in a bit more force. 

 

What would be best? Getting any 20,6mm alu one with 4 holes would do the trick? 

[Leslie green 159]

I think they are all cast iron , gti 1.9 one is anyway so that would be a good upgrade .

[Arthur 20]

Realy, even the 406 ones? Some look so alu on the pictures.. On the site where I buy my parts some are listed as alu as well but then again 23,6 which might be overkill for me

 

Perhaps I could also just get it realy clean and metal paint it. 

Edited Friday at 11:32 AM by Arthur

[welshpug 1,722]

yes a 20.6mm item would bolt straight on, later 205 gti had those as standard anyway,   shared with a MK2 golf from memory. 

[bacardincoke 48 1 Cars]

Ate 03.2120-2031.3 is the iron bodied / 4x outlet MC that fits straight on to 205's, plus a range of different MK2 Golfs, Renault Clios, 19's, Talbots and others etc.etc.

 

If you find one that interests you, stick up the numbers and may be able to confirm it'll work for you.

 

When you see 20 (or 22, 23 etc) at this point on an Ate MC part number, it denotes the bore, helps when searching.

 

Be careful though if you find old stock for example... some were originally 2x outlets (or 3, like the Horizon), and left or right sided, but their latter day replacements are frequently 4 outlets as standard, with plugs to seal off the redundant ones if required.

 

If you're particularly after an alloy one try Ate 03.2120-3943.3 that's pictured below (VW  1H161101019C), fitted to various Golf 2's and 3's plus a few Seats... running one on my own car (when it's not in bits!)

 

23.6 may be a bit of a leap, there's 22.2's  on some 16V MK2 Golfs that may be a lesser alternative if that's what you're after.

 

Searching eBay under the MC's non Peugeot / VW numbers can occasionally throw up a bargain.

 

 

 

 

 

 

 

 

Edited Friday at 01:37 PM by bacardincoke

[Arthur 20]

Wow. Indeed all 19mm seem to be cast iron. Some 406 seem to be alu but 23,8 mm.

 

I have a 306 9 inch booster drum. That used to be 45° off, so I opened that, turned it 45° and put it back together. (with 200% amount of  mounting/rivet points as to original just to be sure)  Been good for 10 years. Simple reason to do that was 306 being 60 EUR and GTI was 200 EUR back then. 

 

But 9 inch booster drum is not on option for right hand drive afaik. There is a dome on the left that let's one fit the 9 inch drum in LHD, but not in RHD afaik. Or is this only mk1 body? Did the French assume you have stronger legs on your side of the pond so you don't need the bigger drums? 

 

Above means I think all 306 cylinders are 45° off. They do however have alu that are 20,6mm and 20,6 would be fine I think. I'm worried bigger would be too hard/short travel for 266 setup or will the bigger booster drum compensate that a bit? I guess no RHD run 9 inch boosters? I guess no-one bothers to go bigger for 266 setup either? 

 

Sorry, was writing this before a had a chance to see the above one.  03.2120-3943.3 is priced as where it made of gold. 

Edited Friday at 02:01 PM by Arthur

[bacardincoke 48 1 Cars]

Which was why I suggested searching under alternate part numbers -

 

Ate

 

Eg., Renault Clio MC, picked up recently for £18 posted, so very doable.

 

[Arthur 20]

Thanks

[welshpug 1,722]

phase1 406 all use the same 23.8mm aluminium master,  phase2 have the mounting studs at a different angle, just like phase2 xsara.

[Tom Fenton 1,633]

Buy the 20.6mm cast cylinder, paint it silver then fit it is what I did.

[bacardincoke 48 1 Cars]

Had a very quick 5 minute look last night Arthur, but remember I'm set up for eBay.co.uk, and didn't have the time to adjust things to include the German and other sites that're likely automatically open to you being in the EU/Netherlands.

 

You may well find better examples.

 

03.2120-2031.3

 

Not saying this is a good seller, feedback is a little iffy, but useful to highlight you can get quality Ate ones at a fair price (not saying other makes aren't, just my preference).

 

Excluding their feedback and the high postage to the UK, if I were after a new MC, that'd be in the running at that price.

 

They're accepting offers too, interesting that it's been listed since early December 2025 and no sales... so could potentially be got for a lot less if you want to be cheeky!

 

Alternatively search solely under the car model, without the part number... for example MC for Renault Clio / relevant year etc., sometimes non business sellers may either not know or bother listing it (that's how I found the one pictured above).

 

Iron Ate's are usually painted (black) and it does seem to preserve them for a long time, plus very easy to redo and bring them back up to like new.

 

 

 

 

 

 

 

 

 

  

 

 

 

 

[welshpug 1,722]

I buy a lot from Autodoc in germany.

 

a silver bosch cast iron 20.6mm unit for £31   

https://m.autodoc.co.uk/bosch/1207030

 

 

 

its probably zinc coated, so a coat of primer then some industrial black or silver paint will do.

Edited yesterday at 10:49 AM by welshpug