golfdave
Autocross Champion
- Location
- Scotland (U.K.)
- Car(s)
- Mk7 Golf GT Estate
While I haven't looked at the ROW cars, it is important to note that for USA, the master cylinder and reservoir ARE different for the Sportwagen with 288mm brakes vs the Alltrack with 312mm brakes:
AT master cylinder is 8V1611021B
AT reservoir is 5Q1611301 or 5Q1611301C (depending on build date)
GSW master cylinder is 5Q1611021A
GSW reservoir is 5Q1611301B or 5Q1611301D (depending on build date)
I then looked up a 2015 A3 Quattro 2.0T, a car which we know comes with the 312mm brakes and it lists the same exact part numbers as the AT, which makes sense since they share the same 312mm front brakes.
So yes, the hydraulics are different between the two different rotor sizes. If you put 312mm brakes on your GSW or Golf, you are not matching them to the correct hydraulics. What the effects are, if any, I do not know.
Looking at ETKA for Europe market
Master cylinder 8V2-611-021(ATE type) or 021 B (TRW type).... has the following PR codes to cover front discs:-
1ZA & 1ZD = 312mm (GTD & DCC cars)
1ZE & 1ZF & 1ZP = 288mm
Master cylinder 8V2-611-021 A.... has the following PR codes to cover front discs:-
1LJ & 1LM = 340mm (R & PP)
1LV & 1ZB = 312mm GTI with 300mm rear discs
So this how to guide is written correctly & my new 312mm brakes are correctly matched to the master cylinder fitted at the factory for the 288mm originals..
Looking at ETKA for USA market
In USA the Master cylinder 8V1-611-021 or 5Q1-611-021 A.... has the following PR codes to cover front discs:-
1ZA & 1ZD = 312mm (GTD & DCC cars)
1ZE & 1ZF & 1ZP = 288mm
https://nemigaparts.com/cat_spares/etka/volkswagen/go/746u/611000/
So a GSW fitted with 288mm brakes in USA will have a master cylinder which will work with 312mm brakes...you are WRONG!!
& to finally knock this on the head it doesn't matter WTF the master cylinder is ...
IF your caliper has "57" stamped on it that caliper is what is used for both the 288mm & 312mm brake disc set-ups as it has a 57mm dia piston, & therefore the hydraulics are the same!! I just had to get a new caliper CARRIER.
Before trying to correct my "How to guides" please read them thoroughly as there is information covering this at the start of this thread!!
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